The Definition of Anaemia is fairly straightforward and widely accepted as being a hemoglobin level below the low normal range on a serum blood test. But what this ‘normal low’ level should be is hotly debated by scientists. However, doctors and laboratories have to choose SOMETHING by which to give a ‘normal’ range such that anemia can be diagnosed.

As such, the ‘standard of care’ for most doctors is to use a 50 year old anemia definition created by the World Health Organization that they admit is ‘arbitrary’1. (see image below).

World Health Organization Criteria for Anemia

Since almost anyone who sees a doctor for any health condition, or even a yearly physical exam, will get a ‘routine’ blood test called a CBC (also called a Complete Blood Count or Hematology Panel), they will also get the tests known as Hemoglobin and Hematocrit that are included in the CBC. It’s the hemoglobin and hematocrit tests that, when low, are how doctors and scientists define Iron Deficiency Anemia.

Let’s look more closely at what some of the studies on the topic say, including the World Health Organization’s widely accepted, but admittedly ‘arbitrary’ standard for the definition of anemia. As you can see in the picture below, the WHO has chosen the level of 13 g/dl as normal for males, and 12 g/dl for older children and non-pregnant females. This is likely the low number on your own CBC blood test below which you will be diagnosed with anemia.

What Studies Say about the Definition of Anaemia

However, in the study The definition of anemia: what is the lower limit of normal of the bloodhemoglobin concentration the researchers ask, “How is it that the WHO standard, so widely used in epidemiologic studies, is so seriously flawed?”

‘Seriously flawed’? So the definition of anemia doctors have been relying on to determine a diagnosis of a serious health problem is ‘seriously flawed’? Interestingly, they give their own table of what they believe the lower limit should be. For men, the numbers are quite a bit higher, but for women, there is a negligible difference. (see image below-proposed lower limit hemoglobin)

Proposed Lower Limit of Hemoglobin
Be sure to look at the UNITS and convert them to the units your laboratory is using if they are different. The differences in the units are simply like the difference between driving in a car with a speedometer that uses kilometers per hour or miles per hour. It merely takes a simple conversion to change one to the other. Here is a conversion site to Convert Hemoglobin Numbers.

Additionally, the definition of anemia should be adjusted higher for those living at altitude, who need more hemoglobin to compensate for the lower oxygen environment 2.

Different Definitions for Blacks and Whites?

In the above table, note that blacks have different median levels of iron than whites. This is true in women, men, and children and it has been determined that these differences are not related to food intake or socioeconomic class 3.

As a result, there is an argument to be made, at least in this study, that blacks actually should be considered to have a different and lower ‘normal’ level than whites. While certainly, this is debateable, and the study noted advocated public resources not be used in the treatment of anemia in blacks who may not fit the same definition of ‘anemia’ as whites, so therefore it could have a bias, the studies seem pretty clear that hemoglobin levels are lower in blacks.

What was not discussed in the study is that blacks are well-known to have lower vitamin d levels due to their dark skin impeding vitamin d absorption. Low vitamin D levels, then, can lead to low iron absorption for several reasons, including increasing the master iron regulator known as Hepcidin, leading us to believe that the Low Levels of Hemoglobin in Blacks is Not a Normal Variation, but is a pathologic problem that should be addressed by having Optimal Vitamin D Levels.

Accuracy in the Definition of Anemia is Not the Issue

While these numbers seem pretty straightforward, the problem is that Hemoglobin and Hematocrit levels can stay stubbornly in the ‘normal’ range, or very close to the normal range, even while iron and ferritin blood levels are very low. So, while it’s true that levels higher than these are not ‘anemia’, the problem is that most people, and even most doctors, assume that the fatigue, or brain fog, or inattention in children is not a problem of low iron so long as the hemoglobin is in the normal range. But this is not true at all.

Studies are extremely clear that Iron Poor Blood, even without anemia, can lead to serious health issues such as fatigue and brain fog that doctors simply will not associate with low iron levels when anemia is not present. Because of this, many people, particularly women, go to their doctor with fatigue, get a Complete Blood Count, have a normal hemoglobin level, and are told that their fatigue is not caused from low iron levels… despite the fact that they could have very low iron levels.

For instance, if you look on the Iron Poor Blood page, you’ll see that the ferritin levels of vegetarians versus omnivores, in two different studies, are as follows:

  • Vegetarians 35 ug/l
  • Omnivores 72 ug/l

Vegetarians have less than ½ the ferritin level of omnivores, you will understand why when you read the page on Spinach for Iron, yet these vegetarians still do not have Iron Deficiency Anemia. On that same page, you’ll note that studies show that ferritin levels under 50 ug/l can lead to Symptoms of Iron Deficiency including fatigue and lack of endurance in athletes. Because these definitions of anemia are based on population curves and not necessarily markers of health problems, a vegetarian or a women with heavy menstruation with a ferritin level of 35 ug/l will have her complaints dismissed as not being a problem of anemia and be sent on her way looking for a different cause of her fatigue!

This is not an enviable situation for millions of people, particularly menstruating women, who will be left suffering with fatigue, sometimes for decades or even for life, when all they need is a simple blood test and an inexpensive vitamin supplement. The solution is that you need to take your health into your own hands and insist on getting a routine iron and ferritin test if you suffer from any health problems.

Or you can simply Order an Inexpensive Iron Panel yourself (if you are in the US) if your doctor is not willing to help you rule out iron deficiency as a cause of your health problems, as should be done in everyone with chronic health issues; both to discover low iron levels, as well as a condition of high iron levels called Hemachromatosis. For those already taking iron, be sure to get the Best Iron Supplement, especially if you are struggling maintaining healthy iron levels. It’s equivalent to intravenous iron and it’s absorbability and  low side effects made it a life saver to me!