Iron state in regular blood donors.

Men, regular blood donors, who had given 420 ml of blood 15 times during three years, or more than 50 times over a longer period, and who had been supplied with 600 mg ferrous fumarate after each donation, were studied with regard to the stain-able bone marrow iron, sideroblast counts, desferrioxamine test, and transferrin, serum iron, and haemoglobin values. Compared to a control group the iron stores of all subjects were found to be considerably reduced, and the total iron-binding capacity was raised. The Hb regeneration was slower than in subjects with greater iron stores, but was complete in 60 days. The iron state in the 50 group was almost identical to that in the 15 group, implying that a balance impeding the progress of the iron deficiency had been achieved between iron absorption - which increases with decreasing stores - and iron loss.