The purpose of this study is to investigate the effect of daily iron supplements after blood donation on time to recovery of hemoglobin and iron stores. The study will also determine whether the effect of iron supplements on time to recovery is different in men and women, in older vs. younger donors (<60 years old vs. at least 60 years old) and in donors with replete vs. diminished pre-donation iron stores.

The effect of taking iron supplements after blood donation on time to recovery of hemoglobin has been documented but it is not clear whether the benefits of iron supplements vary with age, gender or iron stores. To study this issue, individuals who are eligible to donate blood, based on hemoglobin level, will be randomized to receive daily iron supplements or no supplements. Randomization will be stratified on gender (male or female), age (<60 years old vs. at least 60 years old) and iron status (serum ferritin >26 vs serum ferritin no greater than 26). Subjects will be followed for 24 weeks with periodic blood draws to determine time to recovery of hemoglobin and iron stores. A 7 ml (about 1.5 teaspoons) blood sample will be drawn at each of seven study visits over the 24 weeks to track recovery of hemoglobin and iron.

Inclusion Criteria:

• potential blood donors with hemoglobin of at least 12.5 gm/dL
• no blood donation for at least 4 months
• successful donation of a unit of whole blood

Exclusion Criteria:

• individuals who are taking iron supplements including multivitamins containing iron and refuse to stop do so for the 24 weeks of the study.
• baseline ferritin >300 ug/L (to exclude individuals with hemochromatosis)