According to a new US study blood donors who take low-dose iron supplements may restore their pre-donation hemoglobin levels faster.
In the randomized controlled trial, 215 participants who had not donated whole blood or red blood cells within 4 months received an iron supplement with 37.5 mg elemental iron daily or no iron for 24 weeks after donating a unit of whole blood (500 ml) (1). The researchers measured the time to recovery of 80% of the post-donation decrease in hemoglobin and recovery of the ferritin level – an indicator of the amount of total iron stored in the body. The study results showed that compared with participants who did not receive iron supplementation, those who did had shortened time to 80% hemoglobin recovery in both the low-ferritin (average 32 days vs 158 days) and higher-ferritin groups (average 31 days vs 78 days). Recovery of iron stores in all participants who received supplements took a median of 76 days; for participants not taking iron, median recovery time was longer than 168 days.
The researchers commented that although the absolute amount of hemoglobin decrease was relatively small and of marginal clinical consequence after a single blood donation, donating blood is a repeated process that leads to progressive iron loss and anemia in some frequent blood donors, so it is important that the hemoglobin decrease after blood donation be recovered before the next blood donation. Between 25% and 35% of regular blood donors become iron depleted and the study shows that supplemental iron can effectively restore hemoglobin, even in donors with higher iron levels.