In 2011, 9.2 million people in the United States donated 15.7 million units of red blood cells. Unfortunately, for too many donors this generous gift is accompanied by iron depletion and resulting anemia. Now, a new study finds iron supplements significantly reduced donors' time to recover lost iron and hemoglobin, a vital protein in blood, following a blood donation.

“Donating blood is safe and essential for health care,” Dr. Joseph Kiss, the study’s principal investigator and associate professor of medicine at University of Pittsburgh, said in a press release. “This study highlights the importance of maintaining iron levels after blood donation, and shows that supplemental iron effectively restores hemoglobin.”

Blood donors are allowed to give one pint of blood every eight weeks. Yet, upward of one-quarter of all frequent donors become iron-depleted as a result of their routine gift. It can take months to recover the iron lost during a single blood donation, with such depletion linked to fatigue, slight neurocognitive changes, pica, and decreased exercise capacity — anemia. Another possible consequence of iron depletion is low hemoglobin. Importantly, low levels of this protein, which carries oxygen in the red blood cells circulating throughout the body, is the most frequent reason why hopeful donors are not permitted to give to the blood bank.

What can be done for generous blood donors who want to avoid the effects of iron depletion and low hemoglobin levels?

Iron Supplements

New research from the National Heart, Lung, and Blood Institute (NHLBI) points to a possible solution. The Hemoglobin and Iron Recovery Study ran from April 2012 to December 2012 at four blood centers and included 215 blood donors older than 18. Participants included 136 females (63 percent) and 79 males (37 percent). Nearly one-quarter of the participants were older than 60, and although all were blood donors, none had donated in the last four months.

The researchers began the study by separating these donors into two groups based on iron levels: a lower iron and a higher iron group. Half of each group took one tablet of ferrous gluconate (38 mg of low dose iron) daily for 24 weeks following their blood donation. The researchers measured each participant’s hemoglobin and iron levels seven times during the study. Compared to donors who did not take iron, the donors taking iron supplements returned to pre-donation hemoglobin levels faster in both the low iron (five weeks versus 23 weeks) and high iron groups (four weeks versus 11 weeks). Donors taking supplements also recovered lost iron more rapidly than the others (11 weeks versus more than 24 weeks). The researchers also noted "without iron supplements, 67 percent of participants did not recover iron stores by 168 days."

“Maintaining healthy iron levels will allow donors to safely continue donating thereby ensuring a robust blood supply for patients in need,” said Dr. Simone Glynn of the NHLBI.

Source: Kiss JE, Brambilla D, Glynn SA, et al. Oral Iron Supplementation After Blood DonationA Randomized Clinical Trial. JAMA. 2015.