Donation-induced iron depletion is significantly associated with low hemoglobin at subsequent donations.

BACKGROUND: Blood donation is associated with a loss of hemoglobin (Hb)-bound iron. Hb levels recover relatively fast by using stored iron. However, it takes more time to replenish iron stores, potentially resulting in iron deficiency. STUDY DESIGN: Hb and ferritin levels were measured in 5056 new, first-time, and repeat whole blood donors. We investigated whether increasing numbers of donations are associated with lower ferritin levels. Furthermore, we tested whether low ferritin levels are associated with low-Hb deferral at the subsequent donation attempt by performing logistic regression adjusted for age and stratified by sex. RESULTS: Whereas mean Hb levels are relatively stable, ferritin levels significantly decrease with increasing numbers of donations and were approximately 50% lower for donors with >50 donations compared with those with 2-10 donations. Despite the poor correlation of ferritin and Hb levels, cross-sectional, iron-deficient donors (ferritin <15 ng/ml) had 21.8 (8.5-55.6) higher odds in men, 10.1 (6.1-16.5) in premenopausal women, and 11.7 (5.2-26.4) in postmenopausal women for Hb deferral at a subsequent visit. DISCUSSION: To conclude, repeated donations may induce iron deficiency, which corresponds with an over tenfold increased risk of having insufficiently restored Hb levels at a subsequent donation attempt. Longer donation intervals and/or higher dietary or supplemental iron intake are warranted to prevent accumulated iron depletion and subsequent low-Hb deferral in whole blood donors.

Dietary intake of heme iron is associated with ferritin and hemoglobin levels in Dutch blood donors: results from Donor InSight.

Whole blood donors, especially frequently donating donors, have a risk of iron deficiency and low hemoglobin levels, which may affect their health and eligibility to donate. Lifestyle behaviors, such as dietary iron intake and physical activity, may influence iron stores and thereby hemoglobin levels. We aimed to investigate whether dietary iron intake and questionnaire-based moderate-to-vigorous physical activity were associated with hemoglobin levels, and whether ferritin levels mediated these associations. In Donor InSight-III, a Dutch cohort study of blood and plasma donors, data on heme and non-heme iron intake (mg/day), moderate-to-vigorous physical activity (10 minutes/day), hemoglobin levels (mmol/L) and ferritin levels (µg/L) were available in 2,323 donors (1,074 male). Donors with higher heme iron intakes (regression coefficients (ß) in men and women: 0.160 and 0.065 mmol/L higher hemoglobin per 1 mg of heme iron, respectively) and lower non-heme iron intakes (ß: -0.014 and -0.017, respectively) had higher hemoglobin levels, adjusted for relevant confounders. Ferritin levels mediated these associations (indirect effect (95% confidence interval) in men and women respectively: 0.074 (0.045; 0.111) and 0.061 (0.030; 0.096) for heme and -0.003 (-0.008;0.001) and -0.008 (-0.013;-0.003) for non-heme). Moderate-to-vigorous physical activity was negatively associated with hemoglobin levels in men only (ß: -0.005), but not mediated by ferritin levels. In conclusion, higher heme and lower non-heme iron intake were associated with higher hemoglobin levels in donors, via higher ferritin levels. This indicates that donors with high heme iron intake may be more capable of maintaining iron stores to recover hemoglobin levels after blood donation.