The Rationale for Treating Iron Deficiency Anemia

In mild to moderate iron deficiency anemia (IDA) where the hemoglobin concentration is above 7 g/dL, the RBC life span is normal.1The production of RBCs is normal in number, or, in line with the anemia, is somewhat less than normal: production is limited by the availability of iron. In a normal adult, the amount of iron required each day for new RBCs is about 20 mg, all of it recycled from internal sources, most of it from degraded hemoglobin. When the RBC mass in iron deficiency is half the normal size, the recycled iron is about 10 mg/day, almost all going into new hemoglobin. The size of the erythropoietic organ is appropriate to the metabolic state; it is not a seething, hypercellular organ—as in pernicous anemia—held in check by nutritional deficiency. It is important to appreciate the diminished condition of the marrow to understand the basis of appropriate