Iron Metabolism. Iron Stores in Man as Measured by Phlebotomy 1

Hemosiderin and ferritin represent storage iron, available for hemoglobin synthesis when need arises. Previous observations (1, 2) have indi- cated that these stores must be depleted before iron deficiency becomes manifest in the circulating red cell mass. The depletion of iron stores associ- ated with normal hematological measurements may therefore be regarded as the "preclinical " phase of iron deficiency.