Erythrocyte production in iron deficiency anemia.

Erythrocyte production was measured in 21 iron deficiency anemia patients after therapy with parenteral iron. The red cell mass was measured twice with 51Cr and red blood cell survival by labeling with 51Cr. In all cases, erythrocyte production increased in the 12 h following parenteral iron administration (dextran or polysaccharide-iron oxide). Production increased sharply for 3 to 6 days, remained high for 2 or 3 days and fell sharply thereafter. It is suggested that this fall is not due to a lack of available iron.