Iron stores can be depleted without causing anemia. You can have iron deficiency without having iron deficiency anemia. Once our iron stores are completely depleted there is still enough iron present in our body pool from the daily turnover of red cells for normal hemoglobin production. If the deficiency keeps progressing then you can also have anemia. Iron deficiency comes before and is a cause of anemia. What’s normally not well understood is that you can have symptoms at every step of this continuum.

In 2018 an Australian trial showed that testing a group of 299 healthy young women for iron deficiency.

87 women or 29% had iron deficiency.

Of these 87, 16 were anemic.

That’s only 18% of those who were iron deficient.

That’s only FIVE percent of the group total.

The remainder wouldn’t have been identified by testing for hemoglobin alone.

So what’s the point of testing it at all if you don’t test the right things.

We used to test bone marrow to know how much iron was in someone’s blood. It was easy to then see what level of blood ferritin corresponded to bone marrow that was missing iron. One study showed 58% of women were iron deficient when testing their bone marrow.

Iron deficiency and anemia are not the same thing.