Carbonyl iron for short-term supplementation in female blood donors

A randomized, double-blind trial of iron replacement after repeated blood donation was conducted in 75 menstruating women; 51 completed the study. Volunteers were assigned randomly to one of three treatment groups: 1) carbonyl iron (nontoxic elemental iron powder), 600 mg; 2) ferrous sulfate, 300 mg (60 mg Fe++); or 3) placebo, each given three times daily for 1 week immediately after blood donation. Blood samples obtained initially and 56 days later were tested for hemoglobin, mean corpuscular volume (MCV), free erythrocyte protoporphyrin, serum ferritin, serum iron, total iron binding capacity (TIBC), and percent saturation of TIBC. The prevalence of gastrointestinal side effects was similar in both groups taking iron. At the end of the study there was no laboratory evidence of change in iron status in women who received carbonyl iron (n = 15). In those treated with ferrous sulfate (n = 17) the mean TIBC increased (p less than 0.001), and in the placebo group (n = 19) there were decreases in mean MCV (p less than 0.01), serum ferritin (p less than 0.001), and percent saturation (p = 0.027) with an increase in mean TIBC (p = 0.004). Carbonyl iron seems to be effective for short-term iron replacement in repeat blood donors and may have the advantage of decreased or absent risk of poisoning if accidentally ingested by children.