Regular blood donors are at risk of iron deficiency, but characteristics which predispose to this condition are poorly defined.
2425 red cell donors, either first time (FT) or reactivated donors (no donations for 2 years) or frequent donors were recruited for follow-up. At enrollment, ferritin, soluble transferrin receptor (sTfR), and hemoglobin were determined. Donor variables included demographics, smoking, dietary intake, use of iron supplements, and menstrual/pregnancy history. Models to predict two measures of iron deficiency were developed: Absent iron stores (AIS) were indicated by ferritin < 12 ng/mL and iron deficient erythropoiesis (IDE) by log (sTfR/ferritin) ≥ 2.07.
15.0% of donors had AIS, 41.7% IDE. In frequent donors, 16.4% and 48.7% of males had AIS and IDE, respectively, with corresponding proportions of 27.1% and 66.1% for females. Donation intensity was most closely associated with AIS/IDE (ORs from 5.3 to 52.2 for different donation intensity compared to FT donors). Being female, younger, and/or menstruating also increased the likelihood of having AIS/IDE, as did having a lower weight. Marginally significant variables for AIS and/or IDE were being a non-smoker, previous pregnancy and not taking iron supplements. Dietary variables were in general unrelated to AIS/IDE, as was race/ethnicity.
A large proportion of both female and male frequent blood donors have iron depletion. Donation intensity, gender/menstrual status, weight, and age are important independent predictors of AIS/IDE. Reducing the frequency of blood donation is likely to reduce the prevalence of iron deficiency among blood donors, as might implementing routine iron supplementation.