Why You Need To Lab Test Your Iron Status: Hemoglobin, Ferritin & Transferrin As Essentials

Your iron status is somewhat different than other minerals out there: in this case, it's essential to test your levels once in a while.


Simple: you'll never know whether your status is good or not.

The blog post you're reading right now is the second installment in my 5-installment series on iron. The first installment considered  the basics of iron and why it is important for health.

 In the following weeks I'll publish:

  • A third installment, considering the potential problems of iron overload and deficiency, as well as the benefit of having optimized levels
  • The fourth installment, on the best iron-rich foods and the very controversial topic of iron fortification.
  • And, lastly, the fifth installment. Here I give you twenty different strategies to optimize your iron levels. These tips include anything from including specific plant foods to increase or decrease your levels to donating blood and taking supplements.

But, for now, let's consider the topic of lab testing your iron status - with popular iron lab tests such as ferritin and transferrin:


Best Iron Lab Tests: Hemoglobin, Ferritin, Transferrin & Much More

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; 449; 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; 452Iron 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; 452; 453; 454Several diseases, as well as general inflammation make the transferrin saturation also more imprecise to measure.


Advanced Iron Lab Testing: TIBC, NTBI, UIBC & Other Complicated Names

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

I really mean that!

Let me explain why...

Most people don't need to know about these more advanced lab testing options. And yet, for completeness sake - or if you're a nerd like me - I've included the info anway. Feel free to look up the references I've quoted as well if you want more information!

Here we go, the more advanced iron lab testing indicators: 

  • 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; 337; 338; 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; 459; 460; 461; 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; 470; 471; 472; 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.[239As 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...

Overall, 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 basics 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 section, let's talk about testing your levels:


Want To Test Your Levels? Consider Letsgetchecked For Iron Status Tests Such As Ferritin And Transferrin %

Alex has extensively reviewed Letsgetchecked in the past.

The good thing about that home-lab testing service? You don't need to visit a doctor. Letsgetchecked will send you a lab test. You can then draw blood from the comfort of your home and return the test in the dedicated package.

The good thing?

Letsgetchecked offers an iron lab test as well! Discount code ALEXFERGUS saves you up to 20% on testing as well! You can simply click HERE to go to their website, then move to "wellness", and under the wellness header you find an iron status test. 

Again, code ALEXFERGUS saves you a lot of money on the original price.

Unfortunately, the test isn't perfect and doesn't contain all the specifics I talked about in previous sections, but for 95% of our readers, the test is a very good solution!

With discount, the test probably costs you under $100 USD, which can truly be life-changing. 

Keep in mind that if you've got health insurance, you might already classify for testing your iron levels. So before ordering at the website listed above, make sure your insurance doesn't already cover it!

For other cases, where your doctor refuses to test  you or you don't have your costs covered, there's Letsgetchecked.

So, with all those topics considered, let's conclude:



Finishing Thoughts: Only Through Lab Testing Will You Understand Your Iron Status, Such As Hemoglobin, Ferritin And Transferrin

Many minerals are easy: you can still do okay guessing your zinc and magnesium status. With iron, that's not the case.

So here's why I dedicate a full blog post to testing your iron status:

I, myself, didn't test my levels for a long time. I actually thought that I was doing okay, as I was combining my red meat meals with some milk to lower iron absorption. 

But, since a few years, I hadn't been training very intensely many times a week. Up until 2018, I was working out 4-5 times a week, with frequent long sessions.

(Whether working out so much and intensely is healthy is another debate for another day!)

The bottom line? My ferritin levels were sky-high! And, I felt reasonably good. Only by testing did I find out that I could be doing a lot better.

The solution, in my case, was to donate blood. Problem solved. But, you don't know for sure unless you test!

And, the consequences of not knowing your levels? The next, third installment in this series considers the problems associated with both a deficiency and an iron overload. Please know that billions of people have a deficiency on this planet, and many people in developed nations have an overload.

So keep reading and you'll be getting more out of these blog posts!



Items Mentioned

  • Letsgetchecked Iron Status - go to "wellness" on the Letsgetchecked website and use discount code ALEXFERGUS for up to 20% off!


This is a post by Bart Wolbers. Bart finished degrees in Physical Therapy (B), Philosophy (BA and MA), Philosophy of Science and Technology (MS - with distinction), and Clinical Health Science (MS), and is currently a health consultant at Alexfergus.com. 


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