February 23, 2015

Iron Supplements Hasten Recovery in Blood Donors

At a Glance

  • Daily iron supplements can help people who donate blood more quickly recover lost iron and hemoglobin, the protein that carries oxygen throughout the body.
  • The findings suggest a way to improve the health of blood donors and reduce the number who are deferred due to low hemoglobin levels. 
Arm of a person donating blood. Iron supplements may help many blood donors who have to delay donations due to low hemoglobin levels.ninsiri/iStock/Thinkstock.

Every year, more than 9 million Americans donate nearly 16 million pints of blood. Blood donors are allowed to give one pint of blood every 8 weeks. But about 25-35% of regular donors develop iron deficiency. The body needs iron to make red blood cells. These cells transport oxygen and carbon dioxide around the body using the iron-rich protein hemoglobin.

It can take months to completely recover the iron and hemoglobin lost from blood donations. Deficiencies can lead to anemia, a condition in which the blood can’t supply enough oxygen to bodily tissues, causing fatigue and other symptoms. Nearly 7% of donors are forced to delay their donation due to low hemoglobin levels. Deferring larger number of donors could greatly affect the already-strained U.S. blood supply.

One potential solution is to provide donors with iron supplements. Past studies have shown that iron supplementation can reduce the number of iron-related deferrals. Researchers led by Dr. Joseph Kiss at the Institute for Transfusion Medicine in Pittsburgh examined how supplements affect blood levels of iron and hemoglobin. Their study was funded by NIH’s National Heart, Lung, and Blood Institute (NHLBI). Results were published on February 10, 2015, in the Journal of the American Medical Association.

The team followed 215 blood donors, ages 18 to 79, at 4 U.S. blood centers. Participants had previously donated blood, but hadn’t given blood within the last 4 months. The researchers measured participants’ levels of ferritin—a protein that stores iron and can be used as an indirect measure of iron levels. The participants donated blood on the first day of the study and then were placed into 2 groups based on their original ferritin levels: higher and lower ferritin. Half of each group took an oral iron supplement daily for the next 168 days, and the other half didn’t.

In both groups, those taking iron supplements showed faster recovery of iron and hemoglobin levels. Compared to donors who didn’t take iron, those taking iron supplements more quickly returned to 80% of pre-donation hemoglobin levels in both the lower ferritin (32 days versus 23 weeks) and higher ferritin groups (31 days versus 11 weeks). Similarly, donors taking iron supplements recovered iron more rapidly. However, the median time for iron to reach pre-donation levels was 11 weeks among those taking supplements and 24 weeks in the no-supplement group.

“This study highlights the importance of maintaining iron levels after blood donation and shows that supplemental iron effectively restores hemoglobin, even in donors with higher iron levels,” Kiss says.

These results suggest that 8 weeks may not be enough time for many donors to sufficiently recover lost iron, particularly without taking iron supplements. Future studies will investigate the optimal dosage and duration of supplementation as well as which donors would benefit from taking iron supplements. 

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Reference: Oral iron supplementation after blood donation: a randomized clinical trial. Kiss JE, Brambilla D, Glynn SA, Mast AE, Spencer BR, Stone M, Kleinman SH, Cable RG. JAMA 2014 Feb 10;313(6):575-83. doi:10.1001/jama.2015.119. PMID: 25668261.

Funding: NIH’s National Heart, Lung, and Blood Institute (NHLBI).