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Iron, Angel Or Demon? Iron Deficiency, Foods, Lab Tests, And Overload

Jan 10, 2019


You may think:

"C'mon, ANOTHER mineral I need to care about?"

"You've been bugging me about how important magnesium and zinc are as well. Surely iron cannot be important ALSO?"

"You're fear mongering (yet again). If I JUST eat a high-quality diet, there's NO need to worry about getting iron deficient."

"Balanced diets automatically contain the right iron-rich foods."

"People on the carnivore diet consume lots of iron and they're very healthy. So no need to worry about excess iron either!"


Well, I'm telling you anyway (yes, I'm stubborn): iron can be a silent killer that you barely notice.

Smoking cigarettes and air pollution are similar in their effect: they damage you imperceptibly over an hourly, daily, weekly, monthly, and especially yearly basis.

Imperceptible damage is the worst damage, because you never correct for that kind of damage like you do when you cut your finger..

To get back to my point:

The main claim of this blog post is that managing your iron status is important, and that many people do have an iron deficiency or overload.

To be more precise, an "iron deficiency anemia" entails that your body does not have enough iron to create properly functioning red blood cells. Red blood cells carry oxygen throughout the body. All your body's cells depend on that oxygen for their proper functioning.

At the most basic level, an iron deficiency anemia ends up in an inability of your body to perform well.

Even cells themselves become dysfunctional with an anemia, because the "mitochondria" in your cells are directly dependent on iron operate. Mitochondria are the energy producing factories of your cells, and iron deficiency thus causes very low energy levels.

An iron overload, on the contrary, leads to excessive amounts of that mineral being stored in your blood and organs (such as the liver and brain).

The end result of that overload is an increased risk for many modern diseases, such as cancer, heart disease, diabetes, and nervous system problems.

Optimizing your body's iron levels has many benefits though - even though few people take proper action in that regard:

Examples of benefits are better brain performance, improved sleep quality, more overall energy, a stronger immune system, enhanced athletic performance and beauty, plus more...

You don't want to miss out on these benefits, right?

tiger that displays energy, as an analogy of why your iron status is important
Just to visualize optimal iron levels...


So what's the solution? 

How do you optimize your "iron status"?  

With "iron status" I denote the iron stores in your body, whether that's the blood, liver, spleen or other locations. 

Answer: don't guess--use lab tests instead.

While many different iron-related lab tests are explicated in the full blog post, I'll briefly just consider two of them in this summary: hemoglobin and ferritin.

Hemoglobin helps carry the oxygen in your blood, and is dependent on iron in order to be created. Hemoglobin is part of the routinely taken "complete blood count" test, which you can often order through your physician. 

The outcome on the hemoglobin blood test should be 14 and 17 grams per deciliter if you're male and 12 to 15 for females. Lower outcomes entail that you may have iron deficiency anemia. Higher levels entail an overload of iron instead.

Next, I'd recommend a ferritin test. 

Ferritin encompasses the long-term iron storage in your body, and is also a routinely taken lab test. Ferritin levels should be located at 20 - 150 nanograms per deciliter (and somewhat higher for men). Babies and children want minimum levels of 30-50.

(The other diagnostic tests in the full blog posts also help you differentiate between iron deficiency, overload, and other disorders).

Let me explain why I strongly recommend lab testing:

150,000 people die every year due to iron deficiency on this planet. Billions of people are also deficient in iron.

Up to 1 in 9 people are genetically predisposed to accumulate too much iron in their bodies.

Do you know whether you're predisposed?

Do you know what your ferritin levels are?

If not, continue reading... 

If you end up with either a deficiency or overload on lab tests, I highly recommend 1) changing your diet; 2) using one of the 20 strategies in this blog post to manage your iron status.

In this summary section, I'll briefly describe the foods that contain the highest iron content, and 5 of the 20 strategies to manage your iron status yourself.

So let's first consider iron-rich foods...

Seafood and land-based meats, especially organ meats, are the richest sources of iron on this planet. These foods specifically contain what is called "heme iron".

Heme iron is very well absorbed by the human body.

Plants contain "non-heme iron", on the contrary, which is absorbed more poorly than the heme form. While animal foods contain non-heme iron as well, their heme contribution makes them the ideal candidate to increase the amount of iron in your body.

Whether or not you want to increase your iron stores depends on your lab tests. 

In addition to seafood and (organ) meats, other iron-rich sources are (dried) spices, beans, legumes, nuts, and grains - all these contain the non-heme form.

So let's now consider 5 important strategies to manage your iron status:

  1. Take the effects of vitamin C into account.

    Vitamin C can dramatically increase iron absorption from both heme and non-heme sources. If you add vitamin C to beef, for example, the amount of iron you absorb from that meal can increase 2 to 3-fold.

    Vitamin C also counteracts a plant compound called "phytic acid". Phytic acid lowers the absorption of iron from plant foods.

    Raw whole grains, nuts, seeds, beans all contain phytic acid. By soaking, fermenting, germinating, or sprouting these foods that phytic acid content can be reduced--but vitamin C thus also lowers the iron-absorption-inhibiting effect of phytic acid.

    In plain English, eating a simple orange with your oatmeal will improve the amount of iron you absorb from that oatmeal.

  2. Sweat a lot--or not.

    You lose some iron through your skin everyday. Sweating more increases the amount of iron you lose.

    One reason your ancestors may have had lower risks for iron overload is because they didn't spend most of their time in air conditioned buildings and more time in sunlight.

  3. Consider your calcium intake.

    Eating lots of cheese or drinking tons of milk with your meals? That action alone makes a dramatic difference in your iron intake. Calcium lowers the net amount of iron you absorb from a meal - and thus has the opposite effect of vitamin C.

    Simple but effective...

    Of you course, don't take large doses of calcium with your beef if you're iron deficient.

  4. Donate blood.

    Blood donations are the quickest way to reverse an iron overload. A 500 milliliter blood donation contains about 250 milligrams of iron, which equal 10-30 daily the recommended daily iron intake.

    Of course, always consult your physician before deciding to donate blood - advice that rings true for any suggestion I make, but especially this one.

  5. Know your genetics. 

    You can get your DNA tested for your susceptibility of iron overload at or Ancestry DNA.

    Make sure to order these tests as anonymously as possible, so that any data that originates from these tests is untraceable to you as a person.

    Some genetic changes which are more often present in Northern Europeans, for example, increase the amount of iron you absorb by a whopping 3-fold.

    Might genetics thus matter in relation to iron? Damn yes...

For a far more elaborate description of these strategies read the full blog post. 

There are two last issues to tackle in this summary: 1) the issue of whether iron fortified food is healthy, and 2) whether supplementing with iron if you're deficient is healthy

I'll keep it short: while iron fortified foods and supplements can be good (in some instances), they're far from great (in most instances).

Food that's fortified with iron causes lots of gut issues, and hints at a far more fundamental problem: if your food needs to be fortified then it's low quality food anyhow.

Supplementation is far from great either because iron can displace other minerals in your body, such as zinc, manganese, and copper. If you supplement with just iron then you're at a greater risk for creating problems down the line.

The solution?


Either eat foods that are high in iron, such as beef liver (which is extremely cheap as well), or use organ meat extracts to reverse your deficiency. With whole foods or whole food supplements you're not risking mineral imbalances.

In the latter case the safest option is to use some beef liver extract or beef spleen extract:


Liver extract

Beef Spleen


With these caps you can secure your iron intake in seconds a day. There are some instances in which I wouldn't recommend taking oral iron supplements - an example is if you've got gut issues. 

Using canned oysters is a last (but amazing) alternative:

 Canned Oysters.

Buying fresh oystes is better of course...

Ready to see the full picture?

Let me take you on a 20,000 word journey about iron...

Don't want to read the entire blog post? Grab my 10 essential iron laws infographic below:


Last updated: March 25 2019

Save to Pinterest:

cover photo of this blog post

Table Of Contents

Iron Basics:

1. Introduction: Iron, Double Edged Sword?
2. Iron's Role In Human Health

Iron Deficiency And Overload In Context:

3. Iron Lab Tests: Hemoglobin, Ferritin, Transferrin, And More.
4. Iron Deficiency, And Related Conditions Such As "Iron Deficiency Anemia"
5. Iron Overload, And Related Conditions Including "Hemochromatosis".

Why Iron Status Matters:

6. Thirteen Amazing Benefits Of Optimal Iron Levels

Managing Iron Status:

7. Iron-Rich Foods, Your Daily Requirements, And Optimizing Absorption
8. Iron Fortification: Necessary Intervention Or Dangerous Practice?
9. Twenty Strategies To Manage Iron Absorption And Status: Genetics, Blood Donations, And More
10. Iron Supplements: Angel Or Devil Once More?

The 30,000-Foot View:

11. Conclusion: Iron's Role In Health Remains Underappreciated

*Post can contain affiliate links. Read my affiliate, medical, and privacy disclosure for more information. 

Author: Bart Wolbers. Bart finished degrees in Physical Therapy (B), Philosophy (BA and MA), Philosophy of Science and Technology (MSc: Cum Laude), and Clinical Health Science (MSc). 



Just another mineral like zinc, magnesium, selenium, manganese, iodine, calcium, and many others.

I get it...

really do...

Health should be simple, right?

And yet, you may think:

"you're telling me that I need to mind whether I breathe in polluted air, use several strategies to improve my sleep quality, may need to meditate to calm my mind, and even monitor my mineral intake?"

Too much work...

Grandpa and grannie didn't meticulously watch their health either and lived over 90 years old. 

So why worry about iron?

Or air pollution?

Or sleep quality?

Or meditation? 

Why worry?

Simple answer: your life will be much better if you invest in your health. Small changes such as optimizing your mineral intake can have a huge impact on your life over time:

Let me give you an analogy. Let's say you've got a good friend who is great in predicting when the economy enters a recession.

Every decade or so, that friend signals you to sell all of your stock, just before the crash hits.

During a recession, stocks are usually devastated with 50% losses or more, and with his advice you prevent that loss. 

It's a small adjustment that takes you very little time, but if you listen to your friend, your investments would double in value every decade compared to what you'd otherwise get.

In four decades, by preventing all those downturns, your stocks would be 16 times as valuable. Imagine what kind of difference a 16-fold value increase would mean for your retirement age or the money you can pass on to your kids...


Managing your body's iron levels is the same: checking up on that mineral with lab tests just once, and more often if necessary, will have enormous health benefits in the long run.

Solutions are also easy to find if you know how you're doing:

Excess iron can be very quickly removed by donating blood, for example. Living decades with an iron overload, on the other hand, has devastating consequences over time.

Think about that compound effect.

Just imagine if every day of yours was a little bit better.

The principle is the same as walking 30 minutes a day instead of watching television - what difference would that behavioral change make in the long-run?

You may think: "but problems with iron are really rare..."

Not so quick...

Iron deficiency is not a side-issue. More than 150,000 people die every year because of having an iron deficiency.[3] 

Most of these deaths occur in developing countries. 

Up to a mind-boggling 30% of the world's population is so deficient in iron that their health suffers big time.[81; 129; 231] 

That's a whopping 2 billion people. Another 3 billion people have at least a mild deficiency. In total, 5 billion people thus have a deficiency or worse.

And there's more:

16 million women are pregnant while having an iron deficiency worldwide.[439]  Such deficiencies impair the development (unborn) children. A total of 240+ million women of the childbearing age have iron deficiencies.

Still believe I'm fear mongering?

different types of plant foods that cannot prevent an iron deficiency anemia properly
Great foods to prevent iron deficiency--or not? 
Stay tuned to find out...


Even more tragic is that many of people don't even know whether they have a deficiency or excess. You may not know either...

Let me explain:

Many people have genetic predispositions to accumulate iron. Chances are about 1 in 9 to 1 in 300, depending on your genetic traits. 

At least 3 million Americans have a predisposition to accumulate iron--but most of them just don't know they've got the problem. 

That's sad.

This blog post attempts to rectify that mistake.

No mineral may be so controversial and misunderstood as iron. Some institutions and health coaches assume that many people are anemic due to insufficient iron levels. Others claim that an excess in iron intake is extremely widespread, wreaking havoc on almost everyone's health.

Both excessive iron levels and deficiencies matters a lot. 

I'll break the problem down into intricate detail...

So I've got a quick question: do you know what your iron levels are? Iron is a double-edged sword because both deficiencies and overloads are more common than you'd think.

I'll tell you everything you need to know about preventing both.

In the past I've written about other minerals, such as magnesium, zinc, and sodium (or salt). This blog post on iron is a continuation of that series. The reason for the series is that many people can improve their health for pennies a day - even in developed countries.

If you're deficient in magnesium or zinc, almost every area of your life will suffer: your sleep, your thinking ability, your energy levels, mood, social relationships, etcetera. 

The same is true for iron - so let's explore the role of iron in your health.

So let's get started: fasten your seatbelt...




Return To Table Of Contents


As a kid, I remember my mother telling me in the morning I needed apple butter on my bread, because apple "contains lots of iron which will make you strong".

The iron content in apple butter is sourced from the sugar beets that are often included in the product--apples themselves contain almost no iron. But thanks anyway for the good food I had in my youth mom...

Since that time, I knew that iron was important for me, although I didn't know about any of the specifics. You probably know that iron is important for energy production in your body as well, but you may not know all the roles iron plays - this section changes that .

For much of human history, your ancestors were in the dark about the health role(s) of iron as well. I ron nonetheless had a surprisingly long history in relation to human health.

About 5,000 years ago, humans learned to create objects out of iron, and the "Iron Age" began. The mass production of iron objects started around 3,200 years ago, and by that time, many cultures already knew that iron plays a significant role in human health.

2,000 years ago, for example, Romans carried iron tablets with them on ships.[5] The earlier Egyptians, Hindus, Greeks, and Chinese also had a rudimentary understanding of iron's role in health.[6]

The essential role of iron in transporting oxygen, however, was only discovered in 1932.[4] And it turns out that transporting oxygen is just one of the many functions of iron.

So let's consider the full role of iron in human health.

Iron has many very fundamental functions in your body, such as creating and repairing DNA, maintaining proper brain function, keeping your body temperature up, and much more.

a picutre of DNA that is created out of iron
DNA: partially created with iron


Red blood cells cannot be created without iron either. It's precisely red blood cells that carry oxygen in your blood to the other cells in your body--without red blood cells you would die quickly. 

Iron, moreover, is not only found in your blood, but also in the liver, heart, muscles, and many other places.[14-19] The mineral is absorbed from the food in your gut, mostly the small intestine, and then spread throughout many places. 

Almost all organisms on this planet depend on iron, and human life cannot possibly exist without it.[10; 11] 

Fortunately, there's a lot of iron on this planet--the downside is that most iron is oxidized, i.e., has reacted with oxygen.

That oxidized form is unusable for many organisms, and as a result, they need to exert considerable effort to find highly absorbable forms of iron in their environments.[12; 13] Many organisms therefore automatically strive to prevent a deficiency in the mineral.

An excess or overload of iron, on the other hand, is just as damaging as a deficiency. 

During an excess, "free radicals" are created in higher quantities in the body. While free radicals are always produced as a by-product of energy creation, iron excess dramatically increases that process. 

The number of free radicals produced is proportional to the excess of iron. 

These free radicals can damage cells and speed up aging - a problem I'll get back to. Free radicals can also damage fats, proteins, and DNA. You'll thus want to prevent that free radical buildup in order to stay young.

And there's a surprise:

Your body does not have a mechanism to excrete excessive iron.

Let me explain...

Every day you lose 1-2 milligrams of iron - menstruating women lose additional milligrams during their period.[36-38] 

You lose that daily dose because iron is present in the gut lining and skin. Your gut lining rebuilds very quickly, and thus leads to daily iron losses. And because the skin in your body is also continually being replaced, you lose a couple of milligrams per day in total.

Food intake is the main mechanism by which your iron stores increase. You'll absorb about 8-10% of iron from food on average, depending on the food types you're eating. With more animal flesh, that absorption percentage is going to be higher--more plants make that number go lower.

Some of the iron in your body is also recycled. Red blood cells "die" over time, for example, and some of the iron contained in those red blood cells is re-used.[230]

Yes, your body knew about "recycling" millions of years ago...

Bottom line: the amount of iron you consume through food is the main determinant of how much iron you'll absorb.[30; 31] 

Except for menstruation and bleeding, there are not many mechanisms by which you can get rid of lots of iron.

As the body only contains several grams of iron, preventing both an excess and deficiency requires tight regulatory mechanisms. Your liver plays a major role in that regulation, controlling the amount of iron in the bloodstream.[29; 32; 33]

If a compound called "hepcidin" is highly active, iron absorption levels of the body are reduced--with inactive hepcidin, more iron ends up being stored.[34; 35]

You may think: "why is iron a problem in the first place?"

In other words, why modern humans have to manage their iron intakes today? Why does the body not manage its iron intake automatically?

Great questions...

I've got a theory about that process:

During pre-history, our relationship to iron may have been very different.

In a previous blog post on the carnivore diet, I've described how animal foods became more important for our ancestors a few million years ago - especially for human brain development.

More meat and shellfish being ingested entails that more (highly absorbable) iron is consumed. 

So how did your ancestors prevent toxic iron levels in their body, when many people get an overload on a primarily animal food based diet today?

Two likely explanations are parasites and blood losses from a more dangerous lifestyle. If you're living in a developed country you're probably not exposed to parasites and occasional blood loss to the extent your ancestors were.

The fact that the human body doesn't have a mechanism to excrete excess iron also entails that iron overdoses were much less likely than deficiencies in the past. Higher levels of meat were thus not necessarily damaging to your health back then - now they may...

A last variable is that your ancestors exercised a lot. Sweating can increase the iron loss of your body--many modern people never sweat anymore. 

regular bleeding, which hunter gatherher societies experience, lower ferritin levels
Are you living dangerously enough to lose some iron today?

Summarizing this section: you ingest iron mainly through food--your body cannot get rid of an excess. Animal foods are the best iron source, and iron is necessary for many important processes in your body.

In the next section, I'll consider the role of lab tests in assessing your own "iron status". With "iron status" I mean the iron levels that are stored in your body.

health foundations program



Return To Table Of Contents


I've got a very specific reason for treating the topic of lab tests before considering other subjects such as deficiency, excess, or strategies to lower your iron levels:

You need lab tests to understand what a deficiency or excess is, and whether you've actually got an iron deficiency or overload - only then can you manage your status.

I.e., only by understanding the situation you're in can you apply the correct strategy.

to know how iron is affecting you lab tests are needed - a blinded woman is a metaphor for that principle
Trying to lower or increase your iron levels without
lab testing is like trying to navigate a car blindfolded:
you don't know whether any action is the right one.


On the bright side: very basic and inexpensive lab tests already give you a basic impression of your iron status.

One example is the "Complete Blood Count (CBC)" panel, which included both hemoglobin and hematocrit. The CDC is a widely available routine blood test.

Hemoglobin denotes the amount of oxygen carrying red blood cells you have--hematocrit measures red blood cells as a percentage of your blood.

Because the CBC is so widely used, it's often possible to have this lab test paid through your insurance. You can ask your physician about this test.

Regarding the topic of iron, if either hemoglobin or hematocrit are (too) low, then you're at greater risk for iron deficiency.

In that case, certainly consider using the additional lab tests I've included below.

Lab tests are the only method to find out whether your iron levels are too low, normal, or high.

Contrary to your expectation, taking a lab test is not as simple as drawing a sample of blood and putting that blood under a microscope.

Iron is stored at different places, and many different compounds play a role in iron transport throughout your body. Different lab tests thus exist to test iron levels that are stored at different locations of your body.

There's no need to know the exact procedure by which lab tests are carried out. I've done some lab tests myself in the past, but I'm no master in execution of these tests - I'll leave them to the laboratory personnel.

Fortunately, the outcomes of lab tests are mostly standardized so that almost anyone can interpret the outcomes of iron lab tests.

blood samples that can be used to measure hemoglobin or hematocrit
 A blood sample that can be used to test your iron status


Let's consider which specific lab tests to use when investigating your iron levels:

  • Hemoglobin (HgB) are proteins in red blood cells made up of iron. That hemoglobin is necessary for your body to carry oxygen.

    If HgB levels are low, it automatically becomes likely that you'll also have low iron levels. If you're healthy, most iron in your body is found in hemoglobin. 

    HgB levels have to fall between 14 and 17 grams per deciliter if you're male, and 12 to 15 for females. Higher levels than that denote iron overload, and lower a deficiency.

  • Hematocrit, as stated before, measures red blood cell volume as percentage of your blood.[500] 

    Males should have a percentage between 40 and 52%--female slightly lower between 36 and 48%. Children have slightly lower levels than adults.

    Again: lower levels signify an iron deficiency, while higher levels an overload. 

  • (Serum) ferritin denotes the long-term storage of iron in your body.[448-450]  Your body contains a couple of grams of iron, and generally about 30% of that iron is stored in ferritin--most of the rest is stored in your blood.

    As an analogy, you can simply see ferritin as a long-term depot of iron that's available for use when it's needed. If excessive iron is stored (and your ferritin levels are high), then iron can be stored in places it shouldn't go and wreak havoc - such as organs.

    Ferritin is a tremendously important lab test, as ferritin storage of iron is different than hemoglobin storage. 

    You'll want to keep ferritin levels between 20 - 150 nanograms per deciliter (the maximum is somewhat higher for men). Babies and children need minimum levels of 30-50.

    Now, having your ferrritin level located closer to the the lower end of the range, such 20 nanograms per deciliter, may be more proper if you're prone to get iron excess. If you're prone to be anemic on the contrary, then make sure you're hitting at least the mid-range.

    There are no hard rules for ferritin levels. Different laboratories also use different standards for ferritin, but having very high ferritin such as 400 nanograms per deciliter is certainly damaging.

    Caution: the ferritin lab test is probably unreliable if you've got heart, kidney, or liver problems, cancer, or if you drink too much.[456; 457]

  • Transferrin signifies your short-term iron storage. 

    When iron is absorbed in the gut, it's actually transported by transferrin.[21; 22; 451; 452] Iron is transported from the gut to the bone marrow, where the iron is necessary for the creation of new red blood cells.

    Transferrin levels should be kept between 200 – 370 milligram per deciliter. Tranferrin acts as a basis to calculate transferrin saturation, to which I'll return in a moment.

  • Serum Iron (SI), which is made up of both ferritin and transferrin.[455] The common reference range for men is 65 to 176 microgram per deciliter of blood. For women the outcome ranges from 50 to 170 microgram per deciliter of blood.

    A microgram is one thousands' part of a milligram. Observe that women have slightly lower iron levels in their blood (which is also seem on other tests I've included here).

    The serum iron test is best conducted in a semi-fasted state, after you've not eaten for a couple of hours. 

    If transferrin and ferritin are available, the serum iron test is redundant in some cases - the latter tests are more valid.[455] 

  • Transferrin can also be used to calculate a saturation level which is called "transferrin saturation".

    Transferrin saturation simply measures to what extent iron is bound to transferrin. If the saturation is low, the transferrin molecules do therefore not have iron bound to them.

    When the saturation levels of transferrin saturation increase over a period of time, part of that iron gets stored in ferritin. Continually high transferrin saturation levels thus eventually lead to increased ferritin levels.


    If I'm eating lots of red meat that contains highly absorbable iron, and if I'm also susceptible to iron overload, then my transferrin saturation increases, and if I continue with that behavior, eventually my ferritin levels become very high as well.

    Transferrin suturation levels should come in at between 25 and 40%. A lower percentage denotes an iron deficiency--higher an excess.

    For the best results, I recommend combining transferrion saturation and ferritin, as transferrin saturation can be imprecise.[451-454] Several diseases, as well as general inflammation make the transferrin saturation also more imprecise to measure.

(Nerd section: additional lab measurements include:

(Skip this section if you don't like to read the intricate details of lab tests)

  • Total Iron-Binding Capacity (TIBC).[340; 341]

    The TIBC is related to transferrin's capacity to bind to iron. The TIBC number is mainly used to calculate transferrin saturation from serum iron. TIBC can be used to indirectly determine how much transferrin can be used.

    No need to spend much time on TIBC, unless you're curiuos or need more data. TIBC is fascinating as a benchmark for potential transferrin that can be created in your bloodstream - i.e., the amount of "active short-term iron" that your blood can potentially carry.

    A higher outcome on the TIBC entails that less iron is bound, and that you're more prone to be anemic (or iron deficient).

    Normal TIBC ranges are generally located between 250 - 450 micrograms per deciliter.

  • Non-Transferrin Bound Iron (NTBI).[336-339]

    NTBI is the percentage of serum iron that's not bound to transferrin.  NTBI levels are important because this form of iron may be toxic even if there's not an iron overload in the rest of the body.

    I'm not going to treat NTBI in extreme detail here--suffice it to say that you'd want to take a closer look at NTBI if you've got iron overload symptoms without high ferritin or transferrin saturation.

    NTBI can also become very high if transferrin is fully saturated and iron "spills over" into the blood serum - causing damage.

  • Unbound Iron-Binding Capacity (UIBC).[342; 343]

    Transferrin is "saturated" iron". Unbound iron is un-saturated, and UIBC thus denotes the amount of iron that can be potentially carried by transferrin.

    HIgher UIBC levels entail that you're more prone to be anemic, while low levels are associated with an overload. 

    UIBC is used to calculate TIBC, by adding serum iron to UIBC.

  • Gamma-Glutamyl Transferase (GGT)[458-462]

    GGT is an enzyme and plays a major role in the antioxidant system of the body. GGT is located in several organs, and produced by the liver. 

    GGT is important because it measures oxidative stress. While commonly used to assess liver damage, elevated GGT levels can also be a sign that iron is wreaking havoc in your body.

    Elevated GGT levels have been linked to many different diseases. 

    You'll want to keep the GGT number low. You don't want this lab test to exceed above 65 units per liter if you're a man, and 40 if you're a woman - but around 20 and 10 (for women) is better.

    When you get older, GGT levels can increase somewhat, and somewhat higher levels are acceptable.

    In relation to iron, the most important reason for GGT is to assess liver damage due to iron accumulation. Higher GGT levels are also associated with higher ferritin levels.

  • Ceruloplasmin[469-473]

    While ceruloplasmin is mainly a copper carrier, it plays an essential role in iron metabolism as well. Copper is needed to transfer iron into cells.

    Having very high copper (or zinc or manganese) levels also antagonizes iron absorption.

    If ceruloplasmin levels are low, iron levels in the blood can be low, despite having stored lots of iron in organs - iron may not be properly released into the bloodstream, and damage organs.

    Low ceruloplasmin and low ferritin thus warrants additional lab testing...

    Normal ceruloplasmin levels are located between 18 and 50 milligrams per deciliter (40 max for men).

  • Liver biopsy

    A liver biopsy can only be carried out by a medical professional, and can be used as a follow-up test if you've got excessive iron levels in the blood (e.g. high ferritin). 

    The reason for using a liver biopsy is to check whether any organ damage has occurred due to iron accumulation.

  • MRI (magnetic resonance imaging) 

    In an MRI scan, iron overload can also be detected in organs such as the liver or brain.[239] As an MRI scan is invasive, expensive, and time-consuming, it should not be your first option.

That's it: all important iron lab tests

Keep in mind that most of the aforementioned lab tests require fasting, such as TIBC, transferrin, and transferrin saturation. Ferritin is an exception, because it measures the long-term iron status of your body, and is less affected by what you've eaten in the previous hours.

Most blood tests carry very little risks. You may end with some bruises on your arm due to blood drawings, or poor wound recovery around the point of incision.

The biggest problem with taking these tests is if you have an adversity to needles - beware...

"Yes human, lab tests can be complicated, just as the two of us"


The goal in managing your iron status is to prevent ferritin and transferrin (saturation) levels from becoming exceedingly high.

The specific consequences of iron excess (and deficiency) will be treated in the next sections.

While the process of accumulating iron is very complex, the basics can be visualized very easily: you ingest about 10 milligrams of iron a day. A few milligrams of that iron is actually absorbed by the body.

Remember that the human body also loses a few milligrams per day (depending on your needs and lifestyle), and if you're consuming iron in excess of what you need that iron is stored.

The body normally only stores a couple of grams of iron, first in ferritin. If you're consuming lots of foods with a high iron content, those stored grams will thus keep on increasing, and may accumulate in places iron shouldn't go.

And precisely because of the slow (and imperceptible) accumulation of the mineral makes managing your body's iron levels an important long-term process.

Iron levels are deceptive, because you don't immediately notice that you're being harmed. Even if you're in poor health due to iron deficiency or overload, you don't know that iron is causing these issues.

For that specific reason, lab tests are so important.

In most cases getting rid of excess iron is easy. Taking care of deficiencies is also straightforward. And fortunately, deficiencies are rare in developed countries - if you're eating meat once in a while at least.

Now, the complete picture regarding iron status is more complex that I'm letting on here.

Let me give you an example:

In some instances, you can have high ferritin levels without having high transferrin levels. In such cases, more diagnostic investigation is necessary. Kidney or liver problems can cause that scenario, for example.[473; 474]

In other instances, you may not differentiate well between anemia that's caused by insufficient iron, and anemia due to chronic inflammation levels. If your immune system is continually activated, hepcidin levels can increase, which lowers iron uptake, and can make you look deficient.

Increased iron consumption, however, is not the solution in this case, but will make matters worse.

If you find anomalies in your lab tests, I recommend consulting an experienced clinician to evaluate your labs.

That's it: the basic of iron lab testing.

In summary: focus on hemoglobin and hematocrit first, and use transferrin (saturation) and ferritin to gain more clarity. If necessary, order additional lab tests.

In the next two sections I'm teaching you about deficiencies and excesses.



Return To Table Of Contents


Let's start with a definition: 

Iron deficiency can lead to a condition called "iron deficiency anemia", in which your blood contains too little iron.

Anemia and iron deficiency are thus not the same.

The reason for distinguishing between these two concepts is because anemia can be caused through several mechanisms--iron deficiency being merely one of them. I had mentioned that difference in passing in the previous section.

Anemia simply means that the body does not create sufficient red blood cells or that existing blood cells contain very little hemoglobin.



If you've got low hemoglobin, you'll automatically have low iron in these blood cells as well, as iron is needed to create hemoglobin. Remember that iron is needed in blood cells to carry the oxygen that you breathe throughout your body.

You can also be anemic due to hereditary conditions, for example, which is not directly caused by having too little iron available, even though the consequence of anemia is the same.

Blood loss or a diet that doesn't contain essential vitamins such as vitamin B9 or B12 can be other reasons for anemia.[7-9] 

(Both vitamin B9 and B12 are also needed to create homoglobin.)

an animal that eats meat and gets all their nutrients through that means
B vitamins and iron: everything covered.


Additionally, iron deficiencies without anemia also exist.[127; 128]

In that non-aenemic variation, iron stores are still sufficient that hemoglobin levels are not lowered, even though the total body store of iron has dramatically declined.

The problem is that you'll already start experiencing negative health effects with a non-anemic iron deficiency - this circumstance is thus far from optimal.[136]

So how do you know whether you're at risk for getting anemia? 

Let's find out:

The following population groups are at most risk for iron deficiency:

  • Children, especially adolescents, because they're growing and therefore need higher iron intakes.[129-133] 

    Anemia during childhood can bring lasting health impairments, which is devastating. Examples of lasting effects are poorer functioning of the visual and auditory system in the brain, defective brain structure development, declining hormone levels and responses, and poorer sleep patterns,[210-213]

    Around 20% of adolescents are anemic today even in developed countries, which is truly tragic. Parents, please feed kids and teenagers well before buying them an Iphone.

  • Women who are regularly menstruating. As you know now, menstruation leads to iron loss.[134-136] 

    During pregnancy, women also have increased iron needs. More than 20% of women problematically experience an iron deficiency during their reproductive years.[138]

    If you're a young female, I highly recommend to get your iron levels tested. Living with an iron deficiency is like trying to swim against the current...

  • Elderly people[145-148] One problem of iron deficiency in the elderly is that they may indicate the presence of disease, which should make you question whether iron deficiency is a cause or symptom.

    Ferritin levels, on the contrary, are increased with many diseases.

    For that reason, using the transferrin saturation over a longer period of time is a better diagnostic if you're of older age.

    The topic of iron deficiency if you're older is complicated--I don't recommend increasing your iron intake without spending lots of time diagnosing (possible) underlying problems.

  • Athletes, especially if you're an endurance athlete.[149-150] That iron deficiency is even encapsulated in the term "sports anemia", denoting lower hemoglobin and ferritin levels that are often observed in athletes.[152-156] 

    One reason for those lower levels is that athletes simply have more blood in their bodies, which entails higher iron requirements.

    If you're an athlete, you've also got somewhat higher iron demands because exercise destroys red blood cells, and thus iron - which needs to be re-filled.[476] 

    That exercise-induced iron destruction may be another reason why our ancestors had fewer iron overload problems 100,000 years ago.

  • If you're obese.[139-143] Yes, I find this outcome surprising as well. There's a specific link between inflammation in obesity on the one hand, and lower iron levels in the body on the other hand. 

    Ferritin is probably an invalid lab test if you're obese though, as the outcome can be obscured by the inflammation that's associated with obesity.[144] 

    The issue of iron status and obesity is complex, as obese people may store less iron in their blood, while storing more iron in tissues such as the brain and liver.[433; 434] Measuring ferritin in the blood can thus be deceptive. 


    Biopsies and MRIs may have additional benefits if you're obese, as they're a means to double check whether stored iron doesn't cause organ damage.

    Those lower blood iron levels may also explain why obese people can feel more tired.

  • Digestive problems, such as inflammatory bowel disease, in which iron deficiency anemia is a frequent side-effect.[117-121] 

    If you cannot tolerate gluten, then you're also more at risk for getting anemia.[157- 160] Gluten is a protein that's most people consume through wheat and some people don't tolerate. It's not quite clear yet whether gluten intolerance causes anemia, or the other way around - they may be interrelated.

    Bacterial infections with Helicobacter pylori, moreover, are yet another gut-related cause of iron deficiency.[163; 164] Many people have that bacterium in their gut, but it doesn't create problems for everyone.

    Parasites or worms, lastly, are one more cause of iron deficiency.[165; 166] Simply put: an unhealthy gut or digestion causes you to absorb less iron.

  • Any condition with bleeding in the gut.[169-174]

    Bleeding causes an increase in iron loss, giving you an anemia risk over time. Examples of bleeding conditions are stomach or gut ulcers, intestinal cancer, or inflammation in that location.

    The aforementioned parasites can also cause internal bleeding. I'm not going into detail regarding these conditions.

    Suffice it to say that if you find blood in your stool, an iron deficiency is more likely (also get checked by a physician if you've got blood in your stool - it's a red flag.)

  • Skin conditions.[167; 168]

    As some iron is excreted when the upper layer of the skin dies off, some skin conditions can increase the iron demand of your body,

    A higher skin turnover means higher iron demands. Simple, but important to keep in the back of your mind...

  • Vegetarians and vegans are at greater risk because they don't consume the foods that have the highest iron absorption: animal flesh, from either land animals or seafood.

a pale puppy that's an analogy for an iron deficiency anemia
Pale and young. Anemia? Probably not...


So, what are the consequences of being deficient in iron?

Iron deficiency (anemia) causes many problems, such as:[129; 132; 137; 198; 199; 318; 319]

  • Impaired mental performance, such as a lowered attention span or memory problems.
  • Decreased energy levels and fatigue, and poor exercise capacity.
  • "Restless legs" syndrome, which is a nervous system disorder. With restless legs syndrome, you'll have a strong desire to move your legs.
  • Sub-optimal pregnancy outcomes, leading to developmental issues in newborns. Examples are babies being born too early, and getting a depression after birth as a mom.
  • Decreased productivity, and anxiety, worry, anger, and depression.
  • A painful tongue or mouth sores, and poorer nail condition (such as brittle or splitting nails, or abnormalities in nail aesthetics, such as white spots),  
  • Developmental disorders in children if they get anemic, such as problems in the nervous system
  • Hair irregularities, such as worsening hair condition and even hair loss.
  • Slower wound healing

Keep in mind that you don't have to experience all these symptoms in order to be iron deficient. If you've got iron deficiency, for example, you may only experience tiredness and slower healing, while not having nail and hair problems.

The more extreme the iron deficiency gets (as measured by ferritin, for example), the more symptoms you'll probably experience. As iron is so important for most processes in the body, you can also experience symptoms not included in the above list.

With a lower calorie intake, you're automatically more at risk for having iron deficiencies. The reason for that relationship is simple: with lower calorie intake you're more prone to consume fewer milligrams of iron.

Several diseases also cause you to have lower iron levels.[428; 429] Your immune system can be very active and dramatically lower the iron content in the blood, for example, in order to starve pathogens from their iron needs.

Iron deficiency anemia is not benign and increases overall disease risk.

An impaired immune system (making you more defenseless against disease) and heart problems (e.g. heart failure, in which your heart doesn't pump strongly enough for the body's needs) are examples of eventual consequences of a deficiency.

If low iron levels show up on your lab test, it's thus imperative to consider how much iron you're taking in from food (a topic that will be treated later). If you do consume enough iron, it's necessary to check why you've become anemic.

So that's deficiency--let's now look at iron overload:



Return To Table Of Contents


In the previous section I've talked about the dangers of iron deficiency--iron overload or "hemochromatosis", on the other hand, is also threatening.

The word "hemochromatosis" can literally be translated into "iron colored blood". In reality, the name is often used to not only denote excesses of iron in the blood, but also in other places of the body.

So let's consider that hemochromatosis danger: 

Remember the "hepcidin" I talked about in the second section?

If you're predisposed to iron overload, then you can be deficient in that "hepcidin" compound.[215] Hepcidin is necessary to regulate iron absorption in the intestines - lower hepcidin levels lead to greater iron uptake.

With unfettered iron absorption, the mineral will eventually be deposited in several organs, such as the heart, liver, joints, and even skin.[103]

Having a genetic predisposition to accumulate iron and blood transfusions are the main two causes of iron overload.

Some diseases also exist in which you can get an iron overload, such as "β-thalassemia".[216-218] No need to remember that difficult name though. 

Lastly, aging is another cause of iron overload (in the wrong places).

sprinting rabbit to exemplify that both excessive exercise and mineral intakes can be dangerous
An excess in most things is dangerous -
both excessive exercise and iron are damaging.


(Nerd section: because hepcidin function also originates in relation to the liver, it's simple to hypothesize that liver function is integral to iron metabolism. Studies confirm that hypothesis, hepcidin functioning is off in multiple liver diseases.[225-228] While more research is needed, liver function looks closely related to iron status in the body. Supporting evidence: alcohol consumption is also tied to excess body iron stores.[231-234])

Now, hepcidin not just regulates how much iron is absorbed, but also helps control how much is deposted in various organs, such as the brain, kidneys, and liver.[219-224]

If you have a genetic predisposition to accumulate iron, you'll retain up to three times as much iron as a person who does not have the genetic disposition.

Possible consequences?


Just as a deficiency, iron overload increases your risk for getting several diseases:

  • Liver conditions, such as an enlarged liver due to iron accumulation in that organ, liver cancer, or failure of the liver due to diabetes.[319-321]
  • Heart disease, again, reflected in a bigger heart, or the heart's inability to pump strongly enough (called heart failure).[302; 304-308; 322-323]
  • The spleen and pancreas organs may also be enlarged and get damaged.[333-335] The spleen cleans blood and removes old red blood cells. The pancreas creates the "insulin" hormone that helps carbohydrates get into your cells, and damage to that organ creates problems with handling protein and carbohydrates in your body.
  • Autoimmune conditions - such as "Parkinson's", and "Alzheimer's", and "MS".[324-332] In autoimmune disease, your immune system turns against your own body.
  • Gut issues, potentially even colon cancer.[250]
  • Joint and bone problems, such as bone loss or joint inflammation (osteoarthritis).[242]
  • Diabetes, even though iron overload leads to weight loss.[245] You may thus end up with both diabetes and being underweight.
  • Problems with your thyroid organ, specifically "hypothyroidism" - a name for a slow thyroid.[282-285] The thyroid is central to your body's energy production.

And more..

Furthermore, you can recognize iron overload by several symptoms such as:[236-249; 463; 464]

  • Overall fatigue and tiredness, and/or mental problems (such as depression).
  • Shortness of breath, and higher blood sugar levels (due to malfunctioning cells)
  • Possible heart rhythm irregularities
  • Joint pain, especially in the hands
  • Gut issues and pain, and lowered immunity
  • Brain problems, such as poor memory
  • Organ damage, such as to the spleen, heart, thyroid, or liver
  • Losing weight and bone problems (such as osteoporosis)
  • Lower libido, and an absence of menstruation for women, and even infertility. The testicles of men can even shrink with more problematic iron overloads.
  • Changes in skin color - the skin usually begins to look gray or pale.
  • Hair loss

Being tired and joint problems are the most commonly experienced symptoms...

Please observe that many iron deficiency anemia and overload symptoms overlap - testing is thus key (a point I'll keep re-emphasizing).

So what's the catch?


Even in developed countries like the US iron is actually a massive problem.

Let me convince you with some statistics:

1 million Americans have a strong genetic predisposition of excessive iron accumulation in their bodies.[235] Roughly one in 8-10 Americans also carry the gene that puts them or their children at risk for iron accumulation.

15 million Americans, moreover, are currently living with excessive iron levels.

You can assume that these numbers are roughly the same if you're living in Northern countries, as Caucasians carry the biggest risk for the aforementioned genetic predispositions.

How many people do you know who are aware of their body handles iron?

Let me guesstimate: 1% of your acquaintances?

2% tops?

Those percentages lead me to a simple logical inference: 

According to the statistics, at least 8% are at risk, meaning that only 1 in 8 is aware of how their body handles iron - that's far too little.

While I'm not considering all negative health effects of iron overload in this blog post, let's zoom in on a single very important side-effect: "insulin resistance".

In insulin resistance, the body's cells don't take up carbohydrates (mainly glucose) the way they should.[348; 349]

Opinions differ as of why cells don't take up that glucose anymore. One explanation is that insulin no longer does it job, so that glucose remains the bloodstream and cannot be transferred to the cells.

Another explanation is that the cells are already filled up with glucose, and that glucose is not properly used within these cells, which ensures that most glucose remains in the bloodstream.

Many indications exist that iron overload decreases the cell's ability to take up carbohydrates.[350-355] The relationship between increased iron stores and insulin resistance seems linear in many studies. 

In other words, the higher your iron stores, the lower your cell's ability to process carbohydrates (sugars).

Now, the main problem is that insulin resistance and/or diabetes both increase your risk for several other diseases, such as heart and blood vessel problems, brain disease (such as Alzheimer), increased inflammation, obesity, and others.[356-363]

You'll thus want to prevent insulin resistance if at all possible. 

Want more proof of the relationship between iron accumulation and insulin resistance?


Astounding fact: blood donations and blood transfusions (e.g. a decrease or increase in iron-rich blood) instantly affects that insulin resistance.


Insulin resistance immediately decreases after a blood donation--transfusions generally have the opposite effect.[365; 366] A straightforward relationship between excess iron and insulin resistance thus exists.

Summary of the previous sections: how you manage your iron status can thus have an enormous effect on your overall health. Joint health, overall metabolism, energy, brain functioning, and the handling of oxygen are all adversely influenced by iron deficiency or overload. 

In the next section, you'll learn more about the benefits which optimal iron status can confer upon your health.

Stay tuned...

Want my take on iron? Grab my 10 essential iron laws infographic below:


Return To Table Of Contents


managing iron has huge benefits for your overall health, such as increased energy
Finally arriving at iron's benefits...


So let's consider what all that hassle was all about. 

You now know all about iron deficiency and overload, but not yet about what massive benefits optimal iron levels can have...

The following section hopefully convinces you that optimal iron levels in your body are worth having. 

Let's grab the keys to the kingdom...

Keep in mind that you get all the benefits listed below with neither a deficiency nor an iron excess, and thus exclusively with optimal iron levels. Iron: 

  • 1. Helps your brain perform optimally.[175-177; 179-181]

    Having an iron deficiency decreases brain performance so much that it can be compared to a "mild cognitive impairment". Raising your iron levels from a deficiency gives you a couple of additional IQ points, which is incredible.

    Some studies show that iron deficiency can reduce IQ in children by up to 12 points, which is only partially reversed by correcting the deficiency.[178] 

    12 IQ points make a huge adjustment to your life, as, for example, there's generally a 10 IQ point difference between applied science and university graduates.

    Memory, the general processing speed of your brain, the capacity to focus, and overall learning ability may also improve with an adequate iron status in your body.[182-185] 

    Brain signaling substances called "neurotransmitters" also depend on iron. "Dopamine",[187-193] "serotonin",[194; 195] and "(nor)-adrenaline"[196; 197] are examples of neurotransmitters.

    Dopamine makes you motivated, assertive, and happy. Serotonin is more controversial, but it's generally accepted that this signaling substance helps you be calm and accepting - although serotonin may have downsides. (Nor-)adrenaline involve stress responses.

    The gist is that you need iron to create these neurotransmitters in the first place. Without neurotransmitters your brain cannot function properly. Keep in mind that excessive iron is dangerous and reverses these positive effects.

    With iron levels that are too low, you may experience headaches. Why? Well, your body always prioritizes oxygen delivery to your brain. If the brain does not get enough oxygen, blood vessels expand to compensate, which explains why your head feels like it's about to blow off. 

    Headaches inhibit your brain performance, and consuming enough iron can prevent headaches and improve brain function.


  • 2. Boosts your metabolism.[201-204; 477]

    Simply put: having too little iron in your body makes you fatigued while having optimal levels increases your energy levels.

    If you have non-anemia iron deficiency, improving your stores will mostly decrease your subjective experience of fatigue, but not improve your (objectively measured) overall energy levels.

    Iron also boosts your metabolism. A higher metabolic rate entails that you simply burn more calories, even in rest. Upside: losing fat and gaining muscle becomes inevitably easier with a good metabolic rate.

    To understand that metabolic rate, just think of teenagers' energy consumption. Teenagers usually have a very high metabolic rate, and easily burn off any excess food they consume, even if it's junkfood.

    Most people's metabolic rate slows down once they get older, and by that time you'll no longer get away with eating junkfood (or lots of healthy food either).

    And there are more benefits:

  • 3. Improves sleep quality.[205-209]

    Yes, no surprise here: iron even affects your sleep quality - minerals that I've previously written about such as magnesium and zinc do so as well.

    If you don't have a sufficient iron intake, some studies show that you'll move more during your sleep - in other words, you're more restless.

    In a related sense, a condition called "restless legs syndrome", during which you'll get a very strong incentive to move your legs at night, may also be prevented by optimizing your iron levels.

    With anemia, you can also have either a shorter or longer sleep duration than what you'd otherwise have. That longer sleep duration is simple to explain: you need more hours to recover, and you're thus sleeping less efficiently.

    Overall, optimal iron levels are a big win for your sleep quality.

    sleep quality is one main benefit
    Optimal iron levels, or just a kick-ass sleeper?

    Let's move on:
  • 4. Keeps your immune system strong.[252-257]

    Many cells of your immune system are dependent on iron, such as "macrophages", which destroy pathogens, "lymphocytes", which act as a defense in your lymph system, and "monocytes", which are a type of white blood cell.

    Let me explain:

    A harmful substance such as a virus or bacteria may enter your nose, gut, or skin, and trigger an immune response. That immune response is only adequate if immune cells contain the right amount of iron.

    As a result of sufficient iron in these cells, for example, the body can protect itself against infections. Without sufficient iron you'll be more susceptible to diseases such as tuberculosis or malaria.

    Hence eat some meat to keep your immune system strong...

    Moving on again:

  • 5. Helps your body create more energy while decreasing fatigue.[258-262]

    Again, weakness, fatigue, and low energy levels are all symptoms of being iron deficient. These symptoms disappear with the right iron levels in your body, .

    Fatigue almost always have a big effect on your life. High level of fatigue can even lower your overall quality of life. One of the reasons women can be really tired during pregnancy, for instance, is because of the increased iron needs.

    An example of optimized energy levels...

    The next benefit should be pretty self-evident by now:

  • 6. Improves oxygenation.[264-270]

    Improving the availability of oxygen will help almost any process in your body, either directly or indirectly.

    The "energy powerhouses" of your cells, called "mitochondria", straightforwardly use the oxygen that you breathe in. Iron is also in those mitochondria. Without sufficient iron, mitochondria can thus not properly function, and oxygen cannot be used correctly.

    As a result, iron has a huge effect on your athletic performance. The more athletic activity you engage in, especially endurance sports, the greater the number of red blood cells your body contains. Your overall endurance also increases with sufficient iron.

    Having more red blood cells entails that you've got more iron stored in your blood. 

    But let's look at the flipside of the equation: blood donations can lower your exercise capacity if your iron levels are barely sufficient. If you go too far in donating the opposite effects thus occur: remember that shortness of breath is a common symptom of having low iron levels, which is indirectly caused by having lower oxygen levels.

    With excessive blood donations, maximum power output (your explosiveness as an athlete) and maximum oxygen consumption can take weeks to fully recover. Replenishing to sufficient iron levels achieves reverses that effect.

    The bright spot is that you can have increased performance the next day if you ingest adequate iron after having a deficiency. You'll learn about that strategy in a later section.


  • 7. Simply makes you stronger.[271; 272]

    When female athletes were given iron supplements, they got stronger on many weight lifting exercises such as the "clean and jerk" and "power clean". In another study, strength was better maintained throughout the season with iron supplements, on exercises such as bench presses and squats.

    Iron is directly necessary for a compound called "myoglobin" in your muscles. Myoglobin transfers oxygen from hemoglobin into your muscle cells. Next to the blood, the highest percentage of the iron in your body is actually stored in that myoglobin.

    That myoglobin may also increase your performance. 

    Again, keep in mind that athletes deplete iron somewhat faster than the general population.  

    Yet there's more:

  • 8. Helps gut function.[273-276; 281]

    Fascinating fact: the iron you ingest, either from food or supplements, changes the bacterial makeup of your gut.

    Iron can have very detrimental effects when supplemented, as pathogen susceptibility can increase - possibility in relation to the poor absorption of supplemental iron as opposed to food sources.

    Gut inflammation is another possible end result of high-dosed iron supplements. I'll exhaustively treat supplementation in a later section. 

    You may remember that iron is also a necessary prerequisite to build the lining in your gut. Without sufficient iron you will thus not optimally absorb nutrients from the food you ingest. As you know, gut problems also inhibit iron absorption, creating a vicious cycle of poor gut function, less available iron, and poorer gut function (yet again).

    Iron's effect of inhibiting the intestinal structure has mainly been demonstrated on animals, not humans.[277; 278] In humans, however, supplementing with iron does show negative effects on gut disorders, such as "colitis" and "irritable bowel syndrome".[279; 280]

    Stay tuned...

  • 9. Keeps you warm.[282-285]

    Feeling cold all the time?

    In that case, your thyroid gland may be not working properly. The thyroid is located at the front of your neck. 

    The thyroid's main functions are regulating energy and temperature. Iron is necessary for that thyroid to function properly, just as many other minerals (such as iodine and zinc).

    By optimizing thyroid functioning iron is thus able to keep your body warmer (which is a sign of higher metabolism as well).

  • 10. Repairs your DNA.[161; 162; 229] 

    Without sufficient iron, new DNA cannot be created and existing DNA cannot be properly copied. Iron is also necessary for repairing damaged DNA.

    Again, these benefits only exist with optimal iron levels, not an overload or deficiency. In fact, an overload may have the opposite effect, causing DNA damage.[287]

    No bueno...

    Remember that DNA is a kind of "blueprint" of your body, and with damaged DNA you're at increasing risk for aging and disease. 

    Let's continue, in this case for the women (and vain men) out there:

  • 11. Improves your beauty.[200; 248; 249; 288-296]

    Yes, shocker! Hair, skin, and nail growth are all affected by iron in your body.

    With sufficient iron, you'll have normal hair growth, for example. Low iron levels may even play a role in premature hair graying. Hair loss may also result of iron deficiency, which is cured by getting your iron levels up.

    How about skin health?

    You probably know about the effects of iron in that case: remember those pale looking people? 

    While pale skin is a very poor predictor of iron deficiency anemia, lots of people with anemia do in fact have pale skin. Because of lower hemoglobin levels you'll have discolored skin with anemia. Lower hemoglobin causes less oxygen to be present in the skin.

    With sufficient iron levels, on the contrary, you'll have a glowing pink skin that looks really healthy. 

    Iron is also required for proper wound healing, moreover. Iron deficiency, on the contrary, is just one of the reasons of slow wound healing.

    Nails, lastly, are affected in their shape through the iron status of your body.[291] Unfortunately, the effects of iron on nail health are not studied well yet, although a deficiency will cause problems.

    Next, a benefit everyone loves:

  • 12. Helps your organ function better.[297-308]

    Many organs - such as your heart and liver - depend on adequate iron status.

    (Keep in mind that I've already considered some organs in this section, such as the thyroid and intestines.)

    As always, both high and low iron levels are damaging. Additionally, if you've already got a liver disease, then you may also be at greater risk for accumulating excessive iron. Iron accumulation can thus result in a vicious cycle of liver damage, which causes further iron overload, and yet more liver damage.

    While the role of iron in heart and blood health is complex and even controversial, what's very clear is that both a deficiency and overload are damaging to your health. 
    While I'm not going to treat the relationships between iron and disease exhaustively, an iron deficiency, for example, puts you at greater risk for getting heart attacks. 

    Iron overloads increase the risk for "heart failure", in which your heart does not pump blood strongly enough through your body. Additionally, an iron excess can deteriorate your blood panels such as your cholesterol readings.


  • 13. Boosts your appetite.[309-311]

    Interesting finding right?

    In a previous blog post I've mentioned that zinc increases appetite - the same is true for iron.

    Are you underweight, or an athlete who's trying to build muscle? Make sure you're not iron deficient, as you may not be able to crave enough food to increase your weight (and hopefully muscle mass.)

  • 14. Makes you more fertile.[312-315]

    Yes, that's surprising...

    If you're severely iron deficient as a female, it may becomes harder to conceive. The female cycle, and whether you get a monthly egg, can also be influenced through your iron status.

    Men don't get off scot free though, as in fact, iron overload is especially dangerous to men. The structure of the male testicles, for example, is directly affected by an overload. Overload also results in reduced libido, damage to the testicles, and lowered sperm quality.

    Yes, excess iron may be one of the reasons why there's an infertility epidemic in men...


happy dog that signifies brain health and fertility
Brain function? Check. Energy? Check. Great mood? Double check. Optimal? You bet!


So that's it, the full list of benefits you'll get when your body has optimal iron levels.

In the next section, you'll learn how to manage your iron status through your food intake, and how different foods affect that process.

Health Foundations Program


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Food is and should be the primary method by which you manage your iron levels. In fact, in a subsequent section I'm going to make the argument that ingesting iron through food is far superior than using supplements.

But let's first consider different types of foods first, and the different types of iron they contain: 

Remember I mentioned that iron is absorbed in the gut? A specific type of iron, called "heme iron", is found in animal flesh. Heme iron and is absorbed much more readily than non-heme iron from plant foods:

meat as a perfect iron-rich foods
The quickest way to increase your iron status...


Due to the higher absorption levels, heme iron also puts you at a higher risk for iron overload than non-heme iron.[26-28] 

Non-heme form of iron is found in eggs, dairy, and plant foods. About half of the iron in meats--whether sourced from seafood or land animals--is non heme iron as well. In other words, meat from land or sea-based animals contains about 50% heme iron.

About 20-25% of heme iron absorbed, meaning that if you consume 10 miligrams of iron from meat, you'll end up with a net 2 - 2.5 milligrams of iron in your body.

So let's consider the non-heme variant:

Plant foods contain different types of non-heme iron: 

One non-heme type, called "ferric iron" (Fe3+), needs to be converted into ferrous iron (Fe2+) before it can be properly absorbed by the gut. Your stomach acid accomplishes that transformation.  "Fe2+" and "Fe3+" denote the chemical structure of these iron types.

There's a third non-heme iron form, called "Carbonyl iron", but that type is mostly found in supplements.

As heme iron absorbs about 3 times as well as non-heme iron, absorption of non-heme iron is about 6-8%. Non-heme absorption levels can be as low as 1% (in the case of eating raw legumes, for example).

Now you know about the absorption of different types of iron, let's look at how much you actually need:

The daily iron requirement - or the "Recommended Daily Allowance (RDA)", categorizes iron the requirement over different age group:

  • Between 0 and 6 months of age: 0.27 milligrams
  • Between 7 and 12 months of age: 11 milligrams
  • Between 1 and 3 years of age: 7 milligrams
  • Between 4 and 8 years of age: 10 milligrams
  • Between 9 and 13 years of age: 8 milligrams
  • Between 14 and 18 years of age: 11 milligrams (plus 4 additional milligrams for women).
  • Between 19 and 50 years of age: 8 milligrams (10 additional milligrams for women).
  • Over 50 years old: 8 milligrams

Additionally, pregnant women need 27 milligrams and lactating women need 11 milligrams. Athletes also have slightly higher requirements, especially when you've just started exercising.

Let's subsequently consider how you can actually reach these daily requirements...

Below I've included a list of the top-100 iron foods:[447]

Iron content is calculated on a 100 gram (3.4 ounce) of product basis.

Foods containing heme iron are listed in bold. Duplicate foods have been excluded. The highest reading in each food category has been included - e.g., if whale meat had a 72 and 63 milligram reading, the 73 milligram data point was included on the list.

Lastly, I gave preference to whole foods in the list above, instead of their processed counterparts. So if sesame paste and sesame seeds were both available, the latter option was preferred.

So here you go:

  1. Several dried spices, such as thyme, parsley, spearmint, marjoram: 80-120 milligrams
  2. Whale meat: 72 milligrams
  3. Cumin: 66 milligram
  4. Beef organ meat, spleen: 45 milligrams
  5. Celery seed: 45 milligrams
  6. Oregano: 44 milligrams
  7. Bay leaf: 43 milligrams
  8. Walrus meat: 43 milligrams
  9. Lamb organ meat, spleen: 43 milligrams
  10. Coriander: 42 milligrams
  11. Ground turmeric: 41 milligrams
  12. Anise seed: 37 milligrams
  13. Unsweetened cacao powder: 37 milligrams
  14. Fenugreek seed: 34 milligrams
  15. Dried tarragon: 32 milligrams
  16. Duck liver: 31 milligrams
  17. Goose liver: 31 milligrams
  18. Rosemary: 29 milligrams
  19. Black pepper: 29 milligrams
  20. Spirulina: 28 milligrams
  21. Sage: 28 milligrams
  22. Clams: 28 milligrams
  23. Paprika powder: 24 milligrams
  24. Pork spleen: 22 milligrams
  25. Agar seaweed: 21 milligrams
  26. Chives: 20 milligrams
  27. Seal meat: 20 milligrams
  28. Pork lungs: 19 milligrams
  29. Rice bran: 19 milligram
  30. Fennel seed: 19 milligram
  31. Pork liver: 18 milligrams
  32. (Dutch alkali processed cacao: 16 milligrams
  33. Dried sesame seeds: 15 milligrams
  34. Walrus liver: 14 milligrams
  35. White pepper: 14 milligrams
  36. Chili powder: 14 milligrams
  37. Cardamon: 14 milligrams
  38. Chicken liver: 13 milligrams
  39. Turkey liver: 12 milligrams
  40. Oysters: 12 milligrams
  41. Black and red caviar: 12 milligrams
  42. Ginger: 12 milligrams
  43. Caribou rump: 11 milligrams
  44. Cuttlefish: 11 milligrams
  45. Bear meat: 11 milligrams
  46. Wheat bran: 11 milligrams
  47. White beans: 11 milligrams
  48. Dried peppers: 11 milligrams
  49. Lamb liver: 11 milligrams
  50. Mustard seed: 10 milligrams
  51. Octopus: 10 milligrams
  52. Kidney beans: 9 milligrams
  53. Veal spleen: 9 milligrams
  54. Elk meat: 9 milligrams
  55. Chicken heart: 9 milligrams
  56. Chicken liver: 9 milligrams
  57. Irish moss: 9 milligrams
  58. Liverwurst: 9 milligrams
  59. Black beans: 9 milligrams
  60. Cloves: 9 milligrams
  61. Natto: 9 milligrams
  62. Cassia cinnamon: 8 milligrams
  63. Cowpeas: 8 milligrams
  64. Beef lungs: 8 milligrams
  65. Turkey organs: 8 milligrams
  66. Teff (raw): 8 milligrams
  67. Amaranth (raw): 8 milligrams
  68. Lentils: 8 milligrams
  69. Lima beans: 8 milligrams
  70. Watermelon seeds: 7 milligrams
  71. Emu: 7 milligrams
  72. Potatoes: 7 milligrams
  73. Raccoon meat: 7 milligrams
  74. Allspice: 7 milligrams
  75. Yellow beans: 7 milligrams
  76. Beaver meat: 7 milligrams
  77. Sunflower seeds: 7 milligrams
  78. Moose liver: 7 milligrams
  79. Dried radishes: 7 milligrams
  80. Raw cashew nuts: 7 milligrams
  81. Rosemary: 7 milligrams
  82. Lamb lungs: 7 milligrams
  83. Lamb kidneys: 7 milligrams
  84. Parsley: 7 milligrams
  85. Beef liver: 6 milligrams
  86. Flaxseed: 6 milligrams
  87. Pine nuts: 6 milligrams
  88. Liver Paté: 7 milligrams
  89. Oat bran: 5 milligrams
  90. Pork kidney: 5 milligrams
  91. Soybeans: 5 milligrams
  92. Emu filet: 5 milligrams
  93. Bison: 5 milligrams
  94. Mutton: 5 milligrams
  95. Molasses: 5 milligrams
  96. Oats: 5 milligrams
  97. Hazelnuts: 5 milligrams
  98. Anchovy: 5 milligrams
  99. Peanuts: 5 milligrams
  100. Quinoa: 5 milligrams

Organ meats rule the day as you can see, especially from wild animals.

Spices, beans, legumes, nuts, and grains are also good iron sources, except that they don't contain heme iron. 

non-heme iron in plant foods
Not the best sources of absorbable iron...


Note that I've not included fortified foods in that earlier list.


Some cereals have an iron content of a whopping 60 milligrams. Babyfood, moreover, can contain up to 50 milligrams of iron.

That's insane...

The amount of iron present in these foods is far lower when they're not fortified. In fact, I'm going to treat the topic of fortification in a later section so that you'll receive the full picture.

Fastfood was not included in the list above either, due to some very outcomes such as 30 milligrams of iron in cheese - which is certainly an anomaly.

(Cheese normally contains very little iron, at around 1 milligram per 100 grams of product (3.4 ounces.)

Please keep in mind that some of the iron contents in the list above are overestimated.

Potatoes, placed at position 72, have roughly 3 milligrams of iron according to many scientific sources--instead of 7 milligrams as listed above.

The real iron content of many foods is thus probably lower. 

Why include that elaborate top-100 list then? My reason is simple:

You need to understand what the food groups with the highest in iron are to be able to manage your status. If you don't know that pork liver contains lots of heme iron, you'll be loading up on iron-rich foods while you may already have an overload.

And if you don't know what limitations vegetables or grains have, on the contrary, you may end up with a deficiency over time...

Furthermore, realize that the iron content of foods is never set in stone. There's always variation within specific food types.


Plants that grown in low-iron soil end up containing less iron than when they are grown in soils that contain more iron.[478]

The same principle is also true for animal foods, as their nutrient content is almost always influenced by the food that they ingest. 

Now that you've got a general impression of how foods affect your iron status, let's consider twenty different strategies to manage that status better:



Return To Table Of Contents


Remember that I've previously treated the topics of 1) lab testing; 2) the benefits of optimal iron levels, and the side effects of anemia or overload ; 3) the iron content of different foods.

The next step is to give you 20 different strategies with which you can manage your own iron status.

Disclaimer: you do not have to implement all these strategies.

Instead, implementing just one or two strategies (such as donating blood or ingesting calcium with your meals) can already dramatically influence the iron levels in your body. The more strategies you implement though, the greater the effect on your iron status. 

chessboard that exemplifies the appproach to the current topic
Strategy: one step at a time...
Checking-mating your iron status


So let's begin:

1. Make sure your gut functions well.[23-25]

Remember that the gut, specifically the small intestine, is the main place where iron from your food is absorbed?

Also recall that I've previously mentioned that gut disorders such as gluten intolerance or "inflammatory bowel disease" lower iron absorption in the gut.

While the topic of healing your gut is enormously complex, and cannot be treated in this blog post, if you do have gut issues I highly recommend experimenting with different diets.

Examples are a diet higher in vegetables and tubers (insofar these foods do not trigger you), or a diet that's very low in fiber (such as the carnivore diet).

Suffice it to say that gut problems are problematic and can cause iron deficiency. The simplest way to test whether you've got gut problems is to check whether you've got consistent and firm stools, and whether you're having stomach pain or indigestion...

Then there's a related strategy:

2. Ensure you've got adequate stomach acid.

This one's really simple:

You need sufficient stomach acid to properly absorb iron from food.[367; 368] In fact, taking prescription drugs that reduce stomach acid can lower the absorption of iron by a tremendous 30%. 

A 30% loss can lead to a deficiency over time...

And surprise, surprise: 

Lots of people in modern society also have low stomach acid levels. Yes: contrary to popular belief, low rather than high stomach acid is dangerous. 

A condition called "gastric acid reflux", for instance, in which stomach acid enters your throat is most often caused by insufficient stomach acid levels.

Infections to the stomach, such as "Helicobacter pylori", may also decrease the iron you absorb from a meal.[369-372]


Adding some betaine HCL to your meals is a simple test to diagnose whether stomach acid is an issue. Betaine HCL increases stomach acid. If you feel very warm after a meal when taking betaine HCL, it's a sign your stomach acid was low initially, and that food breakdown has improved.

That's it...

Let's now consider the most important variable for your iron absorption: 

3. Know your genetics.[108]

While in my blog about the carnivore diet I've claimed that an all-meat diet may be perfect for eliminating food sensitivities, iron is a possible downside of such a diet.

Let's say you're exclusively consuming meat without the addition of any plant foods. Depending on you activity level, you'll need 2-8 pounds per day of (red) meat per day, which massively increases your iron intake.

Remember that meat contains 50% heme iron, which puts you at an even higher risk for an overload. 

A conservative estimate is that 1% of the world's population has a genetic predisposition to iron overload, called "hereditary hemochromatosis" which comes down to 70 million people.[251] 

Caucasians actually have a 5-fold increased risk for getting hereditary hemochromatosis. Men are also at greater risk because they don't have periods.

Because a wide array of genetics variations can cause hemochromatosis, up to 1 in 9 people may be at risk in more Northern countries - you thus need testing...

The way to find out whether you're at risk for iron overload is to do a DNA test, such as at or Ancestry DNA.

Make sure to protect your privacy and use all confidentiality options you have been given by law.

For example, if you use the saliva test at 23andme, it's possible to opt for the complete destruction of your sample if you wish to do so. That option does not mandate them to delete your data (based on the sample), but still, you can anonymously process a testing kit to counter data buildup on you as a person.

You can then take the raw data of the test and put it through an online analyzer. The 23andme also gives you basic information about iron overload or deficiency, but does not allow you to manually analyse the data.

So let's consider the relationship between iron and your DNA, and why your DNA can be a problem in relation to iron.

Genetics 101: some parts of that DNA can "mutate". A "mutation" simply signifies a permanent DNA change. Changes in your DNA can be beneficial or detrimental - which option is the case often depends on circumstances.

Many processes in your body can be altered as a result of a mutation. Due to mutations you can have changes in your sleep pattern, for example, or your risk for nervous system diseases, your musical abilities and...: your iron storage.

Let's explore my claim that changes in DNA can be both beneficial and detrimental.

50,000 years ago, when your ancestors may have lost more blood than people today on a consistent basis, and were infected with more parasites, a DNA mutation that increased iron storage could be very beneficial.

In the modern world those same DNA mutation can be detrimental, because you don't lose blood on a monthly basis while hunting and you're probably not infected with (many) parasites either.

So let's consider how DNA exactly affects how your body handles iron - I'm mainly going to cover the basics:

The HFE gene is most important. You can have a "C282Y" mutation in that gene, which causes changes in hepcidin levels. I've mentioned hepcidin earlier.[397; 398]

To be more precise, hepcidin levels are very low when you've got that mutation, which causes the body to accumulate more iron.

There's nothing you can do about that mutation, except use the strategies in this section to manage your iron status. With that mutation, the same meal will make you absorb much more iron than a person who does not have that mutation, all other variables being equal.

There's more:

The TFRC gene contains the "TfR1" and "TfR2" proteins which influence transferrin in your body - it's also possible to have mutations in that gene.[399-403]

Remember that transferrin is bound to iron in the blood.

Mutations in these genes can also cause iron overload.

Thirdly, the H63D gene is also associated with iron overload.[479-481] I recommend checking these genes when you're putting your genetic data through an online analyzer.

Lastly, the S65C is probably also responsible for iron overload, although it's not as dangerous as the previously stated mutations.[482-486] In other words, mutations in the H63D gene is generally less problematic than the C282Y gene.

(Nerd section: other important mutations may also exist, such as hepcidin antimicrobial peptide (HAMP), which also plays a role in hemochromatosis type 2 (in addition to the HFE2 gene).[404-406] The other side of the medallion are G6PD mutations, which can cause low iron levels due to red blood cells disintegrations.[407; 408])

Bottom line: your genetics can make an incredible difference in how your body handles iron.

If you're of European descent, or have a history of heart disease or diabetes in your family, I highly recommend testing your genetic predisposition for iron accumulation.

weird animal that exemplifies how genetics can affect your ferritin status
Far too many mutations?

4. Donate blood to lower your iron intake if necessary.[103-107]

Blood donations are really an amazing strategy if you've accumulated excess iron.

There's a large variance in how often you need to donate blood: if you have a tendency to accumulate too much iron (and thus tend to have very high ferritin levels) you may need to donate blood up to multiple times per year.

If you're managing your iron intake very well, however, with the other strategies in this blog post, then you'll be at much less risk for an iron overload - even if you're genetically predisposed. 

Blood donations are thus not always necessary, even though it's the quickest way to lower your iron levels.

Be careful with donating blood too frequently: many frequent blood donors eventually become iron deficient - especially if you don't have a predisposition for iron overload. Up to 50% of men who frequently donate have iron deficiencies, and 66% of women.[109-111; 115; 116]

The following logical inference should thus be common sense: the more often you donate, the higher your risk for iron deficiency. Most blood donors do so multiple times pear year, as 70-90% of donated blood originates from repeat donors.

If you're not genetically prone to accumulate iron over time, then you'll need about 1 milligram of additional iron per day for every 500 milliliters of blood that you donate during a year.

Every 500 milliliters of blood you donate lower your ferritin levels by about 30 nanograms per milliliter.

So what if you want to donate blood, but don't want to end up deficienct?

In that case, follow these guidelines:

Most men can retain adequate iron stores with 2-3 donations of 500 milliliters of blood per year. If you're a woman, that number comes down to 1 and maybe 2 with a great diet. More frequently donating a smaller amount of blood may also be a good solution for women--donating too much blood at once can put you in a deficiency quickly as a woman.

The bottom line is that blood donations are the perfect method to lower iron stores (such as ferritin) that are too high. I do recommend relying on lab tests when opting to donate more frequently, however.

5. Understand how blood transfusions can cause iron overload.[99-102]

The reason blood transfusions cause iron overload is that you'll habitually receive new blood that contains lots of iron.

To be exact, half a gram (500 milligrams) of iron can be found in 1 liter of blood. Remember that pregnant females - who are the group with the highest iron needs - only need  27 milligrams of iron a day. Adult males only need 8 milligrams. 

With a 500 milliliter blood transfusion you'll thus ingest a whopping ~10-30 times your daily requirement. Of course, the dosage of the blood transfusion (i.e., the milliliters of received blood) may be lower, but with a quarter of a liter you'll still end up with 5-15 times your daily iron needs.

These transfusions are mostly dangerous if you're reliant on them due to health conditions, specifically red blood cell transfusions that contain the iron itself. 

I'm not going into too much detail regarding this strategy, as its only applicable to a very small group of people.

Nevertheless, I did want to mention blood transfusions to make sure you'll look into this topic if this info applies to you.

Moving on:

6. Consider the role of plant compounds such as "phytate", "tannins" and "polyphenols".

Phytic acid is a compound found in differing amounts in plant foods. The role of phytic acid is to prevent plants from being eaten by animals. Phytic acid binds to minerals such as iron or zinc in foods, thereby lowering the amount of minerals you absorb.

From all plant compounds, phytic acid is one of the most problematic in inhibiting iron absorption.

Seeds, nuts, grains, and legumes contain high levels of phytic acid. To reduce the phytic acid content of such plant foods, you'll need to soak, ferment, germinate, and/or cook them. 

So how does that process work?

Let me give an example:

To properly absorb the minerals in nuts, it's best to soak nuts for 8-12 hours overnight in salt. Make sure the nuts are fully submerged in water. Drain the nuts the next morning. Subsequently place the nuts in a dehydrator to reduce their moisture. 

Only after completing that process will you absorb all nutrients. I know the process is time consuming, of course, but treating nuts in somewhat larger batches will save you time.

To fully understand how to soak, sprout, germinate, ferment, and cook plant foods, I highly recommend the Nourishing Traditions book by Sally Fallon.

Example why treating most plants matters: without preparation, you only absorb 1% of the iron in legumes - which can be a benefit or a downside, depending on your iron status.[487] Most vegetables, moreover, only require cooking.

If you remove all phytic acid from grains or legumes, the amount of iron that's absorbed can increase up to 12-fold.[42] Overall, the average absorption increase due to proper plant food preparation is located around 3-10 fold range.[44; 45; 48; 49; 53-55]

Adding some vitamin C to your meals, through either vegetables or fruit consumption, also decreases phytic acid's effect.[44; 61]

The upside?

If you frequently consume plants that contain phytic acid, your body slightly gets used to the effects and increase its iron absorption somewhat.[46] Don't rely on that process though, as you're still taking a risk deficiency relying on mostly phytate-rich foods.

Many people who rely on phytase-rich foods have nutritional deficiencies.

And there's more to consider in the area of plant compounds:

Tannins, secondly, also lower iron absorption.[57; 373-375]

Tannins are yet another antinutrient that has close ties to iron absorption inhibition. Only plants contain tannins. While tannins are usually subsumed under the polyphenol category (which I'll consider soon), I'd still like to treat tannins in detail here.

Whether you tolerate tannins partially depends on your genetic code - for that reason some people do really well on plant foods, while others do better on plenty of animal foods.

Berries, tea, and coffee and red wine all contain lots of tannins - tannins give red wine that astringent taste. Tannin levels are lower in fruit juice because these compounds are generally removed so that a sweeter product is created.

Fresh fruits thus contain more tannins than juice. 

Berries, several grains, grapes, legumes, beans, and several vegetables such as squash contain higher levels of tannins. Chewing really well on tannin-rich foods may reduce their impact on iron absorption, as compounds in the saliva inhibit the effects of tannins.

tea is one of the most well-known iron inhibitors
Iron inhibitor extraordinaire...


Polyphenols, thirdy, should also be taken into account. Polyphenols are also exclusively found in plants.[45; 50]

Don't get me wrong...

if you can tolerate them, polyphenols can be amazing for your health. Fortunately, most people can tolerate polyphenols. 

Foods that contain many polyphenols, such as chocolate, coffee, or tea, can lower the iron content you get from a meal.[56-58; 72]


One cup of coffee contains about 200 milligrams of polyphenols.[59] When you consume 100-400 milligrams of polyphenols with a meal - which can be accomplished by consuming 2 cups of coffee - iron absorption is decreased with a whopping 50-80%.[60]

Adding coffee (or better yet: coffee with chocolate) to a meal can thus dramatically lower iron uptake. 

Would polyphenols thus be an important variable to take into account? You bet!

Lastly, curcumin also reduces iron accumulation all by itself:[466-468] turmeric also inhibits heme absorption
Simply adding turmeric to your meal decreases iron absorption.


Use that food streategically...

So what's the catch? Should you always maximally avoid tannins, phytic acid, and other plant compounds to increase iron consumption?

Of course not...

In fact, including minimally processed plants may be used as a strategy to decrease iron absorption if necessary. Again, increasing or decreasing your absorption thus depends on the context...

There's even evidence that including plant foods directly protect against the damage of iron overload. Many of the compounds discussed before can act as antioxidant in your body if you tolerate them, bringing a net-positive health benefit.

Let's move on to the next iron-inhibiting compound:

7. Mind your calcium intake.[62-71]

Yes, that's right.

Just drinking one glass of milk with your meat already decreases iron absorption.

As you know right now that you may be much more susceptible to having problems with iron absorption due to your genetics, calcium's role can be both a blessing or a curse.

By now you should be able to
identify three iron inhibitors in this picture...

To be clear, you don't have to drink milk to get calcium. Small bones in found in fish are another great source, as are properly prepared (sea)vegetables and nuts. If all of these foods are not an option to you, I recommend getting a calcium supplement.

One problem with using calcium may be that it only acts for a very short period of time, and that your body gets used to the iron-inhibiting effect. Calcium may also mostly have an effect if your calcium intake is already low

Non-heme iron may not be affected, so that calcium inhibits absorption more from seafood and meat than from plant foods.

(The topics of calcium and blood transfusions make me think of the Maasai tribe in Africa, who drink cow's blood as part of rituals. Fortunately, they often mix the blood with milk. How's that for intuition?)

Next, another variable:

8. Take your vitamin C intake into account.[73-80] 

vitamin C and fructose can lead to hemochromatosis, and fruit intake thus needs to be managed
One of the ultimate iron boosters...

Remember I mentioned vitamin C before, in the context of inhibiting phytic acid's effect on lowering iron absorption.

Vitamin C may have an additional effect though, in helping to convert iron from one type into another (Fe3+ to Fe2+). Moreover, vitamin C also increases ferritin level and helps iron stay in the cells - all these effects lower your overall iron requirement.

Why consider vitamin C?


Lots of people take vitamin C supplements to prevent a cold or boost their immune system. Independent of whether that strategy is successful for preventing disease, vitamin C supplementation can increase the amount of iron you absorb from a meal an extreme 2-3 fold

That's right, 2-3 fold...

If you're thus not aware of the effect vitamin C is having, then you might end up with much higher levels than you'd presuppose. 

Additionally, there's an elephant in the room: vitamin C is added as a preservative to many foods.

Just a little vitamin C already increases iron absorption. Some foods that contain naturally high levels of highly absorbable iron, such as meat, also contain vitamin C as a preservative.

Usually that vitamin C is listed on a product description under the name "ascorbic acid"

That's double trouble...

As a side note: in the last few years it's become more probable that higher levels of vitamin A increase iron absorption as well.[123-126]


Hopping on to some minerals:

9. Watch your copper, zinc, and manganese intake, which can all interfere with iron absorption.[81-90]

These ones are simple...

Let's start with zinc:

Foods highest in zinc content include shellfish, meat, dairy, and eggs. Some plants contain high levels of zinc as well, but that zinc is less well absorbed if plants than zinc sourced from animal foods.

Fortunately, high iron and zinc foods mostly overlap in nature. That means that in most cases, you won't end up with an iron deficiency if you're eating zinc-rich foods.

So what's the exception to that rule?

Easy: if you take zinc supplements, you're at greater risk for having iron deficiencies. Zinc and iron depend on a similar process in the liver for their absorption, and taking high zinc doses can displace iron.

The reverse is also true: taking iron supplements can cause zinc deficiency...

Zinc and iron also co-depend on each other, on the other hand, so that a zinc deficiency can make you end up with a iron deficiency as well.[82; 88] If you're deficient in zinc, you thus thus have to test your iron levels also.

If your zinc comes from supplements (chemically known as "inorganic zinc"), then the iron-inhibiting effects are the strongest.[86] Non-heme iron absorption is most affected.

Secondly, you may think: "how about coppper?"[93-98]

Same story, although somewhat different.

With lower copper levels, you can end with lower iron levels as well.[93; 96] Copper is needed to properly absorb iron (remember the ceruloplasmin I mentioned earlier?)

Oysters, liver, leafy vegetables, lobster, cacao products, and mushrooms are great copper sources. 

High levels of copper, hence an excess, will also decrease iron absorption. Overall, you'll thus need to find a golden mean between a copper deficiency and overload. 

The case of manganese, lastly, is really special: manganese directly counteracts the effect of iron.[442; 444-446]

Beans, legumes, nuts, most whole grains, leafy vegetables, and cacao are great sources of manganese.

If you include manganese-rich foods into a meal, iron absorption will probably be slightly lower. The fact that manganese-rich foods counteract iron absorption may be one reason why vegetarians and vegans are at greater risk for iron deficiency...

Lastly, other minerals such as lead (commonly known as heavy metals) also gives you problems with iron absorption.[91; 92]

While I'm not treating these minerals in this blog post, you may keep them in the back of your head for reference.

Bottom line: some minerals you consume can affect iron consumption, but you should mostly be worried if you're supplementing with zinc and/or copper.

10. Animal protein may increase iron absorption all by itself.

Yes, next to heme iron, animal protein also increases iron absorption.[39-41; 47; 49] Non-heme iron specifically increases most in retention.




Let's say you're eating a meal of rice and beans. Adding some animal protein then helps your body absorb the iron from those plant foods, through a mechanism that is irreducible to the addition of heme iron in the meal. 

Other compounds in animal foods except protein may also play a role in increasing absorption.

One reason meat has an iron-absorption-increasing effect may be that meat increases stomach acid production. Increased stomach acid results in more iron from other foods being absorbed.

Caveat: there's some conflicting evidence on the role of protein and iron absorption.[51]

Moving on:

11. Watch your wine intake

Wine is a special case: when wine that's high in polyphenols is consumed with meals, iron absorption decreases.[379-381] Red wine contains about 10 times as many polyphenols as white wine.

If you're drinking wine in the absence of food, however, the effect is very different. In that instance, wine increases your iron stores. The reason is that wine contains some iron by itself, and with the absence of food, that iron is a net-positive contribution to your iron status.

Another caveat: the evidence on the effects of alcohol in the wine itself are somewhat conflicting right now. Alcohol may increase absorption, while polyphenols have the opposite effect

red and white wine have different effects on heme absorption
Q: "Had a rough week?"
A: No, not at all, I had to drink to 
manage my iron status...
(Best excuse in town...)


12. Lower ferritin with sunlight or infrared.[344-347]

Although this strategy is more speculative, there is some proof that sunlight and infrared light can lower your overall ferritin levels.

Let's first recap:

Remember that sunlight consists of 1) ultraviolet light (which can give you sunburns); 2) visible light (the colors of the rainbow), and 3) infrared light (that feels as heat on your body. Ultraviolet and infrared light are invisible to the human eye.

the light spectrum
The light spectrum...


While that relationship may seem far out, let me explain. Hemoglobin contains an iron chemical in the middle. That iron reacts to sunlight. 

High ferritin levels may be a response to having low infared and ultraviolet light in your environment, in the sense that the body compensates for lower light levels by increasing ferritin. Why? Well, when you move into the sun, blood actually transfers to your skin.

That blood is "irradiated" with ultraviolet and infrared light, in which sunlight reacts to the iron in your blood. 

Many people may thus have an iron overload because they're simply not spending much time outside in the sun.

Sweating, moreover, also causes you to lose some iron through the skin all by itself.[443]

What's fascinating is that some people have experienced lower ferritin levels after integrating infrared saunas into their lives. I'd love to see people testing their ferritin levels before integrating more sunlight into their lives, to observe what happens.

For nerds: higher ferritin status - although this is speculation not verified by empirical evidence - may thus be an adaptive response increase irradiation exposure to sunlight.[488]

sunlight affects transferrin and ferritin levels - picture only displays the sunThe house (the environment you live in)
always wins (in predicting your health trajectory).

13. Mind your environmental iron exposure.

Yes, really:

Some occupations naturally put you at risk for iron overload.[382; 383] If you're an electrical worker or work in the metal industry it's therefore very important to use lab tests.

Don't guess what your iron status is...

Metal dust is one example of environmental iron exposure that's dangerous. That metal dust can simply be viewed as a form of "air pollution" - I've written extensively about air pollution

The lungs are one of the best mechanisms to absorb substances - that's why people smoke marijuana instead of eating it. If you inhale iron, that iron may directly end up in your bloodstream, causing damage everywhere.

Other environmental sources of iron exposure also exist, such as cookware. When cooking in iron, a small amount of the mineral can leach into your food every day. Over time you can end up with an overload with that method.

Cooking in iron pans can add a tremendous 30-500% additional iron to your meals compared to what you'd normally consume. Liquids such as sauces are especially dangerous, as the leaching percentages end up on the higher range of the previous percentages..[489]

Let's now return to an "old acquaintance":

14. Keep parasites into account

Parasite infections have been truly underappreciated as a source of iron deficiency. In fact, the more parasites are contained in your body (such as hookworms), the lower your iron stores become.

While the topic of treating parasite infections is far too complex to consider in this blog post, suffice it to say that improving general health is the most important strategy to get parasite infections under control.

What's fascinating is that our ancestors - at least, primates - are almost universally affected by parasites. 85% of chimpanzees have a parasite infection.[384] Another study found 65% of chimps affected by parasites, and 85% of gorillas.[385]

In developing nations, people have parasite infections as frequently as 4-90%, a number that averages around 20-40%. That number is much higher in poorer countries.[409-414]

(Just be happy that I'm not including a picture of parasites.)

Let's move to another danger:

15. Avoid soy

Soy is always a great food to avoid, as there's almost no upside to consuming most forms of soy (except, perhaps, natto).

One detriment of soy is that it decreases iron absorption. Soy is often consumed by vegetarians and vegans, and should thus be carefully considered if you're on a diet that's already low in absorbable iron content.

Despite the high amount of antinutrients contained in soy, such as "phytic acid", soy also independently decreases iron absorption. In other words, even if you fully remove the phytic acid from soy, iron absorption will still be inhibited.

16. Fructose

Fructose is a carbohydrate that's found mainly in fruit and honey. Fructose may increase iron absorption, although conflicting evidence exists. Animal studies demonstrate an increase in iron uptake exists, while human studies show no effect.[386; 387] 

Fructose is thus probably a net-contributor to your status, and will not lead to deficiency. Fruits which contain both high levels of vitamin C as well as fructose can thus skyrocket your iron uptake...

The reason bear meat was so rich in iron earlier?
(Bears love honey)

17. Organic acids

Lactic acid and citric acid - added to food supply - are examples of organic acids.[74; 388-390]

Some substances in nature naturally contain compounds such as lactic acid or citric acid. Citric acid is found oranges, for example, while lactic acid is found in fermented milk products.

Consuming these products  increases iron absorption. When you add a product high in lactic acid to a meal of maize, for example, iron absorption doubles.

It's precisely problematic that these foods are added to the food supply, because you can end up with much higher iron absorption levels than you'd initially assume. 

Citric acid, for example, is sometimes used as a meat preservative. The iron in meat already absorbs enormously well, and adding citric acid bolsters that process.

Is some vitamin C (ascorbic acid) that's added to the mix as a preservative? That's double trouble. 


18: Young women: mind your monthly cycles and contraceptives

I've exhaustively treated this option above, but just wanted to include this info as it's an essential strategy. Bottom line: If you're menstruating, then you're losing more iron - up to double the amount of adult men.

Let's make some calculations:

Women lose about 60-100 milliliters of blood during their period. Over the course  of a year, that number roughly equals two blood donations of 500 milliliters. 500 milliliters blood contain 250 milligrams of iron, so women lose an additional 500 milligrams of iron on a yearly basis if they're menstruating.

Bring on that steak...

Some counterarguments exist though, claiming that menstruation barely increases iron losses. Please read that counterargument as well if you're a young woman.


Some contraceptives such as the pill lower the amount of blood loss women have on a monthly basis. In that case, your period will thus have less of an effect on iron stores.

In poorer countries, where you're already at greater risk for developing iron deficiency anemia, contraceptives can exacerbate that problem (although the benefits of contraceptives still massively outweigh the downside risks in most cases).[391; 392]


Almost done:

19. Watch the alcohol intake

Yes, I know I've talked about red wine, which is a special case. Alcohol in general, such as beer, is very different from wine when looking at iron absorption levels.[393-395]

In some cases, drinking alcohol actually increases your body's iron stores - if alcohol is rich in organic acids. Drinking alcohol with meals that contain plant foods as opposed to outside meals can thus have totally different effects.

Alcoholics generally have increased iron stores because of continually drinking without eating, while storing the small amounts of iron contained through alcoholic beverages. 

the surprising role of alcohol in ferritin management
Please don't use alcohol to up your iron status...


20. Future possibility: use prescription drugs to regulate your iron status

This strategy is somewhat more speculative, but bear with me:

Since some time, a class of prescription drugs called "hepcidin agonists" have entered the research domain.[376-378] By targeting hepcidin, you can control how much iron is stored in the body. 

Hepcidin agonists stimulate hepcidin levels, which lower iron levels--hepcidin antagonists accomplish the opposite.

Unfortunately, the hepcidin agonists and antagonists prescription drugs are still in the research phase and have not entered the market yet.

Prescription drugs should also be your last resort, however, as blood donation and especially dietary changes are generally much healthier methods than using prescription medicine  (and are understood in terms of their side-effects). 

BONUS strategy (because you've been reading all the way up until here): realize that your 24-hour day and night rhythm has a massive impact on your iron status.[501-503]

This link has only been discovered since a few years, but has been backed up by evidence.

The gist is that disruptions in your day and night rhythm can alter the iron status of your body. Iron status - just as as fat loss, cogntive function, or sleep - is thus disrupted by circadian mismatches.

For more background on that tip, read my blog post about blocking blue and green light at night. In that blog post I demonstrate that blue and green light - from television screens, smartophones, and artificial light - disrupts your brain's melatonin production, which in turn decreases sleep quality.

Another speculated - but probable mechanism - is that blue light also affects iron levels through skin exposure. It's thus recommended if you spend lots of time under artificial light, not only to wear blue blockers but also to cover up your skin.

That mismatch in your day and night rhythm may create changes down the line in your ferritin or transferrin status. Fixing an overload issue may thus involve blocking blue and green light and getting sufficient sunlight during the day.

In essence: there is reason to believe that the artificial light in your environment affects the iron in your blood and skin.

So that's it: twenty strategies + 1 bonus tip to manage your iron status.

But you may think: "how to apply these strategies?"

Well, the first step is to become more aware of what you're doing to increase or decrease iron levels. The second step is to know your iron status through lab tests, then change your behavior accordingly.

Caveat : there's no mathematical formula I can give you to on how to apply these strategies. The interaction between the several strategies is so complex that it's hard to gauge the results without extensive lab testing.

Of course, you know that your iron levels will be higher if you add orange juice to a meal (which contains citric acid, fructose, and vitamin C, which all increase iron absorption). 

I thus recommend to use common sense. If you're genetically predisposed to iron overload, you probably have to use more of the strategies to balance your intake - the same is true if you're a vegan.

If your lab tests turn out optimal, proceed as you've always been doing.

Let me give you some examples:

  • If you're a vegan and eating meals with soy, polyphenols, tannins, and phytic acid, add vitamin C to plant foods that are rich in non-heme iron, and consume calcium rich foods and coffee outside your iron-rich meals
  • If you're deficient, then eating liver with orange juice may be the quickest way to skyrocket your levels once again.

Very simple...

Next, a more controversial topic:



Return To Table Of Contents


Did you know that many food are fortified with iron in many places on this planet?[1; 2] Fortification entails that vitamins or minerals are added to one or more food groups, to ensure that populations ingest enough of those nutrients.

Many countries add iron to the food supply, but few of these countries are located in the developed world. 

It's mostly African, South American, and Asian countries that add iron to the food supply - and the US, Canada, Australia, and UK.[490] Most other developed countries do not engage in iron fortification of food. 

In the US, wheat and rice are currently fortified with iron.

Fortifying foods is somewhat of a problem though, as it's hard to opt out from such a program if you're strongly relying on foods such as wheat.

fortified foods contain low quality iron
Wheat flour mostly contains nutrients because they are 
added. In the past, "fortification programs" were called actually 
"restoration programs". The previous name correctly
entailed that most nutrients were lost during food processing.


From a historical perspective though, food fortification is not novel:

Even in Greek mythology - the myth of Jason and the Argonauts - iron fillings were added to wine to strengthen warriors.

Large scale food fortification by countries only began far later, in the 1920s, when the iodine mineral was added to salt in the United States. Iodine fortification successfully prevented thyroid problems in millions of people.

After that period, it became mandatory to add vitamin D  to milk. Over time, more and more foods were fortified with nutrients, and many nations followed suit.

One example is fortifying food with vitamin B9 - or folate.[418-420]

In some countries folate was added to the food supply because deficiencies in that vitamin cause fetal issues in pregnant women.

The problem with the strategy is that hundreds of thousands of people are exposed to excessive folate even though fetuses are indeed saved. The folate form that governments add to the food supply, however - called "folic acid" -  is also poorly tolerated by many.[491-495]

Excess folate may also cause issues all by itself, such as damage to DNA, colon cancer, genetic mutations, and changes in the immune system. Fetuses exposed to folic acid may also develop new problems that were previously non-existing.

Food fortification is thus not always benign, and can have unintended consequences. - food fortification should thus not be blindly accepted as healthy.

As often, the good does not equal the great.

But let's consider food fortification programs from yet another perspective: countries that have to fortify their food with nutrients automatically concede that the diets of their populations are sub-par.

Insane but true...


Well, if diets supplied all the nutrients populations in these countries needed then no fortification would be necessary.

An example is the mineral "iodine". Iodine is added to the salt in many countries because most people consume too many land-based foods which are generally low in iodine. seafood, especially seaweed, contains very high iodine levels.

If people simply ate the right food, such as some weekly oysters, then adding iodine to food would not be needed. 

On the basis of the presence of food fortification programs it can thus be concluded that populations are systematically underfed (or better: malnourished). It's also very probable that fortification programs miss many unidentified food compounds that are very beneficial.

The flipside of my argument is that fortification should not be blindly rejected either.

Fortification with several nutrients, such as vitamin B1, B2, the mineral iodine, have saved millions of lives and and improved billions.

So how about fortification with iron specifically?

Let's find out...

Again, in the US, Canada, Australia, and UK, most wheat-based products are fortified with iron.

Universally fortifying foods with iron is dangerous in the sense that if you've got a genetic hemochromatosis susceptibility , you're now going to be at much greater risk for overload if you consume wheat.[415-417]

Many other problems associated with iron fortification though.

Adding iron to foods almost certainly increases digestive problems, such as inflammation in the gut and poorer bacterial gut makeups.[421-425] Your risk for getting infections may also increase from iron food fortification.

Additionally, iron that's added to food is different from most supplemental forms. Iron used in fortification is absorbed only 36% as well as supplemental iron - which may partially explain why some people have stomach issues consuming fortified foods.[427]

Even infant formulas are fortified with iron nowadays, which may not always lead to the best health outcomes.[440; 441]

There's an interesting overlap, moreover, between foods that many people do not tolerate (such as wheat) today and iron fortification. In fact, gluten intolerance has become more prevalent since the period iron fortifications began.[436; 437]

Iron fortification can create problems if you're not anemic: antioxidant capacity may go down, for example, speeding up aging, due to an increase in the free radicals I mentioned earlier.[430-432]

Food fortification is important, however, because many people will end up with deficiencies without such programs, even in developed countries such as US.[438] 

Again, that's insane...

That fact alone demonstrates how bad the diets of most people are. 

That statement should not be glossed over, as its logical implications are terrifying: without adding vitamins and minerals to the food supply, many people would be deficient in iodine, iron, B vitamins, and many other compounds.

The standard American diet is thus fundamentally nutrient deficient as well.

So let's question the ruling narrative:

Why not fix the diet instead of relying on food fortification when a country's population is deficient in nutrients, especially in developed countries?

The US spends $3.5 trillion dollars on health care per year. US citizens could all afford oysters and liver, if the money was simply spent on it, so that no fortification would be necessary (and its related side effects would disappear as well).

Worldwide, the problem is worse though:

In more than 60 countries, iron, vitamin B1, B2, B3 and B9 all have to be added to wheat flour.[490]

In 20-25 countries, vitamin B6, B12, and zinc are additionally added. Does wheat flour seem like an intrinsically balanced food?

Again, I'm not against food fortification per se, as 300,000 nervous system developmental defects in children are prevented with vitamin B9 fortification on a yearly basis.

In another sense though, that problems is truly tragic, as billions of people on this planet don't have access to basic necessities while others fly around in expensive airplanes polluting the environment.

But let's move back to iron...

Right now in the US, 20 milligrams of iron is added per pound of many plant foods, such as breakfast cereals, grains, flour, and rice.

In the UK, white bread iron fortification is mandatory, while some other food groups such as margarine and cereals are voluntary.

As a conequence of these policies, iron consumption has almost doubled from 1910 in the US.

Adding so much iron to the foodchain can cause problems, because as mentioned in a previous section, minerals such as iron, zinc, manganese, and copper compete for absorption. 

When you artificially only add iron to a food such as wheat, the relative risk for getting too little zinc increases exponentially. And yes, zinc problems are indeed very prevalent in the US right now...

So what's the alternative? I'll tell you: creating large scale oyster farming programs, and actually eating the beef liver that's now often discarded (yet another tragedy)

Oysters are the perfect food in nature.

Oysters have an extremely high nutrient density, and contain all the minerals that most people are generally lacking.

These beauty's contain all the nutrients that are commonly used in food fortification programs, such as iodine, zinc, iron, and all B-vitamins. Moreover, oysters also have vitamins and minerals in highly absorbable form.

oysters are the best source for heme iron

There's limitless room in lakes and oceans to produce such oysters. In fact, oyster farms don't take up any room, and even filter the water they're located in.

It's possible to build very deep vertical farms with oysters, so that very little space produces lots of high quality food. Oysters also don't need to be fed fish that's low on the food scale, or plants, which are necessary for foods like farmed salmon.

(One counterargument that has emerged against oyster farming is that they emit lots of greenhouse gases such as CO2 and methane, although I'm not fully convinded of that claim.)

Governments could also simply recommend that their citizens consume some beef liver, kidney or spleen or shellfish once in a while.

All problems solved...

It's truly tragic these foods are no longer consumed and are processed into dog food.

And I'm not done yet with my grievance - let's move on to another controversial topic: supplementation...



Return To Table Of Contents


Let's look at the role of supplementation in preventing iron deficiencies. 

The only reason to ever take iron supplements is if your low iron levels have been established through lab tests. And even then, I'm going to argue that taking supplements shouldn't be your first option. 


Let me tell you:

Iron supplements have downsides that iron-rich foods don't have - which is analogous to iron fortified foods.

If you supplement with high doses of iron, it's easy to get other minerals such as copper or zinc out of whack. And getting the dosage exactly right, specifically in relation to other minerals, is difficult to do without lab tests.

Another problem is that iron supplements cause direct side-effects. These side-effects include diarrhea, nausea, irritation of the gut, and constipation.[497-499] And no: these side effects don't just occur when you take too high a dosage--side effects occur at recommended dosages...

Insane but true...

To avoid these side-effects, take iron supplements with a meal and drink enough water to prevent constipation. 

The upside?


Iron supplementation have been proven two work to restore your iron status after blood donations, for example.[112-114] 

Of course, you only need supplementation if you're deficient after a donation. High quality foods to replenish iron stores have not been tested in large scale scientific studies yet, although a better effect than supplementation may reasonably be expected.

Warning: at higher dosages, iron supplements can cause bleeding, organ failure, and eventually coma. Thus keep iron supplements away from children. If children pop a few iron pills during "play", the end result can be fatal.

So what's the solution?

Well, if you don't want to supplement, I recommend you do this instead:

Your best option is to use iron-rich whole foods to increase your stores.

Again: liver, oysters, and lobster come to mind - find the list of optimal choices in section seven.


There's a "but" though:

In some instances, iron supplements are necessary, specifically intravenous supplements.

"Intravenous" (IV) means that the supplement is directly put into your bloodstream. The reason IV supplements are sometimes necessary is because some people cannot properly digest iron from food or supplements.

If you've got gut problems, for example, then an IV might be your perfect solution. In "inflammatory bowel disease", which I've talked about earlier, iron supplements may actually aggravate the problem.[117; 119; 122]

If you've got gut problems that are so incapacitating that you can no longer digest iron, then please seek help from a medical professional.

In other cases, there's another short-cut (click the picture to view the product):

Liver extract

I only recommend using that liver extract only if you do not eat beef liver every week. If you already consume beef liver, which is very high in iron (23 milligrams per 100 grams (3.4 ounces) of product), then you don't need this product.

Beef liver is also very high in copper, and consuming too much of the stuff is counterproductive, as you'll end with a copper overdose.

Next, there's beef spleen extract (click the picture to view the product):

Beef Spleen

Keep in mind that beef spleen is extremely rich in iron. Twelve capsules of Ancestral Supplements beef spleen (pictured above) yields 2.5 milligrams of heme iron.

If you take twelve capsules with iron absorption enhancers described in section eight, you're almost certainly golden (unless you've got gut problems, for example. You can use lemon or lime juice (for both citric acid and vitamin C), for instance, with 6-12 capsules of beef spleen, so that all these 2.5 milligrams are maximally absorbed.

For overall health benefits (if you don't yet eat liver), then I recommend using beef liver over beef spleen. If maximum iron absorption is your goal, take the spleen.

Using canned oysters is a last (but amazing) alternative:

 Canned Oysters.


Buying fresh oystes is better of course...

Now, again, I generally do not recommend supplementing with iron--getting your iron though the food supplements listed above is your best bet. Getting your iron through whole foods is even better...

If you do decide to take supplements anyway, which I can understand in some situations, so that you may as well take the best.

Quick joke: "I don't always supplement with iron, but when I do, I use Ancestral Supplements".

Ancestral Supplements is the company I've listed above, that sells the Beef liver and spleen. 

Why that specific company?

Well, their products are sourced from cows that grow up on grass, and keep eating grass until they're slaughtered. These cows are also not exposed to GMO foods, pesticides or hormones. And lastly, the supplements are 3rd party tested for purity, and don't contain fillers.

Doesn't get better than that...

That's it, all you need to know about this amazing mineral. So by the way, congratulations, you're now an expert on iron.

Let's conclude...

My take on iron? Grab my 10 essential iron laws infographic below:

Health Foundation Program


Return To Table Of Contents


The case study of iron demonstrates that health is not as simple as many people would believe it is. 

Health is much more than "eating less and exercising more", or "calories in, calories out". While the latter statement may be true, it's also completely nonsensical.


Well, "calories in, calories out" is per definition true from a thermodynamics perspective, but the statement is strongly misleading in the sense that the total calories burned by a human being can alter over time.

The effect of a mineral such as iron is a great example of that principle. Why? Well, iron is very central to your body's energy production. 

Too little iron, and your basic metabolism is not going to be what it should be. In other words, you're burning fewer calories and producing less energy when you're anemic. Every process in your body is affected when your metabolism slows down.

In that case the statement "calories in, calories out" still holds true, but is also still highly misleading and dangerous, because it implies youjust need to watch the calories they eat and burn off more calories if you're overweight.

The true reason for being overweight in that case might be an iron deficiency, which is causing a slowdown in metabolic rate.

The final message of this blog post is that you should care about your iron status if you want to optimize your health.

No excuse...

Both a deficiency and overload are highly problematic, and slowly ruin your life.

Taking care of that problem can make you feel on top of the world, just like you (probably) did in your 20s. And fortunately, iron status problems are very easy to fix in 99% of cases.

The bright side of my message is that you're in full control.

You deserve the best. Get your iron status fixed today.

Don't guess.

Don't go through life blindfolded. 

So in the end, the question of "iron, angel or demon", can be answered with "both"! You choose...

For other blog posts, see:

Zinc: Forgotten Mineral? Best Zinc Foods, Supplements, And Secrets

Why Everything You've Heard About Salt Is Wrong (Seriously) And How To Easily Manage Your Sodium Intake

Rethinking Magnesium: Why You're Deficient And Need To Supplement (Quick Fix)

Cannabis: CBD (Oil) And THC For Health? Yes! The Scientific Verdict (2019)

The Carnivore Diet: Unsustainable Fad Or Archetypal Human Diet?

Sources for further in depth reading on the science of iron in the human body:

  1. The Conversation: why iron intake and metabolism matter
  2. National Institute of Health - iron basics
  3. Chris Masterjohn, PhD, on managing iron status
  4. Heme and non-heme iron difference and basics
  5. Systematic review: the role of iron in human health
  6. Systematic review: iron deficiency anemia basics
  7. Systematic review: oral versus intravenous supplementation
  8. Systematic review: deficiency anemia in relation to gut issues
  9. Systematic review: how several pathologies influence ferritin status
  10. Systematic review: iron deficiency anemia and pregnancy
  11. Systematic review: the validity and reliability of diagnosing a deficiency and overload
  12. Systematic review: ferritin and metabolic syndrome; diabetes risk
  13. Systematic review: vegan and vegetarian diets and iron status
  14. Systematic review: iron fortification of foods
  15. Diagnosing and treating (hereditary) hemochromatosis
  16. Lab tests online for testing for hemochromatosis; Lab Corp for the same purpose
  17. Lab tests online for transferrin and TIBC, UIBC testing; serum transferrin testing at Lab Corp
  18. Lab tests online ferritin testing (serum); Lab Corp serum ferritin test
  19. WebMD and the conventional view of hemochromatosis - which currently has scientific consensus; the same view by the CDC
  20. Iron institute: juvenile hemochromatosis
  21. Iron institute: Anemia due to chronic inflammation


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