Side effects of iron supplements in blood donors: superior tolerance of heme iron

Regular blood donors were enrolled in a double-blind, parallel group study to evaluate the side effects of two iron supplements, one containing both heme iron and non-heme iron (Hemofer, 2 tablets = 18 mg iron/day), the other non-heme iron only (Erco-Fer; 1 tablet = 60 mg iron/day). No differences were found between the two alternatives in regaining predonation iron status as measured by serum ferritin and hemoglobin levels. Despite this therapeutic equivalence, participants' symptom diaries showed substantial differences in the side effects for the two treatments. The frequency of constipation (p < 0.05) and the total incidence of all side effects (p < 0.01) were significantly higher for non-heme iron when compared with the heme iron-non-heme iron combination and a placebo. The study demonstrates that a low-dose iron supplement containing both heme iron and non-heme iron (Hemofer) has fewer side effects when compared with an equipotent, traditional non-heme iron supplement.