The study, published online in JAMA, noted that between 25% and 35% of regular blood donors become iron depleted. The randomised controlled trial aimed to test whether oral iron supplementation had an effect on haemoglobin recovery time and recovery of iron stores in iron-depleted and iron-replete blood donors.
Led by Dr Joseph Kiss, from the Institute for Transfusion Medicine, the team reported that low-dose oral iron supplementation, compared with no supplementation, significantly reduced the time to recovery of post-donation lost iron and haemoglobin.
"Donating blood is safe and essential for health care,” said Kiss. “This study highlights the importance of maintaining iron levels after blood donation, and shows that supplemental iron effectively restores haemoglobin, even in donors with higher iron levels."
"This research brings us another step closer to understanding how to maintain healthy iron levels in blood donors. Maintaining healthy iron levels will allow donors to safely continue donating thereby ensuring a robust blood supply for patients in need," commented study co-author Dr Simone Glynn, who leads the Blood Epidemiology and Clinical Therapeutics Branch at the NIH's National Heart, Lung, and Blood Institute (NHLBI).
Kiss and his team randomly assigned 215 eligible study participants (who had not donated whole blood or red blood cells within 4 months) to receive one tablet of ferrous gluconate (37.5 mg of elemental iron) daily or no iron for 24 weeks after donating a unit of whole blood (500 ml).
The study was conducted at four regional blood centres in the United States. The primary outcomes for the study were time to recovery of 80% of the post-donation decrease in hemoglobin and recovery of ferritin level - an indicator of the amount of total iron stored in the body.
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), said the team.
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, they added.
Indeed, without iron supplements, 67% of participants did not recover iron stores by 168 days.
"Although the absolute amount of hemoglobin decrease was relatively small and of marginal clinical consequence after a single blood donation, donating blood is an iterative [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," the authors noted.
Volume 313, Issue 6, Pages 575-583, doi: 10.1001/jama.2015.119
“Oral Iron Supplementation After Blood DonationA Randomized Clinical Trial”
Authors: Joseph E. Kiss, et al