Iron and blood donation.

Regular blood donors undergo a progressive decline in iron reserves, while some develop frank iron-deficient erythropoiesis. The prevalence of iron depletion is significantly higher in menstruating women and increases progressively as the rate of donation increases. While conventional screening programmes based on the haemoglobin are adequate to prevent the development of progressive iron deficiency anaemia, they provide no indication of the development of tissue iron depletion. Recent studies indicate an impairment in a number of physiological processes associated with iron depletion but the liabilities of mild iron deficiency have not been fully defined. While it would be desirable to avoid iron depletion in regular blood donors only a minority of the eligible population have been willing to provide the blood resources of the USA in the past, and many individuals who can maintain high rates of donation without developing iron deficiency anaemia would be eliminated. However, there is little doubt that continued efforts should be made to encourage a broader base of volunteer donors. Improved public awareness of the need for blood has made it possible to obtain 88 per cent of the total supply from donors who gave blood three or less times during the year, and only 13.4 per cent of men and 11 per cent of women made three of more donations (Table 6). Further, women under 46 years of age constitute only 1 per cent of all donors who give four or more times during the year. Until clear-cut evidence is obtained of the deleterious effects of a lack of iron, the low prevalence of depleted iron reserves in men and non-menstruating women donors seems acceptable. However, current blood banking practices place a disproportionate iron demand on menstruating women. Because of the additional burden of pregnancy in this donor group, efforts to reduce the prevalence of a lack of iron in the child-bearing female should be encouraged. The simplest approach would be to limit the rate of blood donation to a maximum of three per year. This also is a subgroup among whom the application of more specific screening procedures for iron deficiency can clearly be justified. Iron supplementation programmes are also an attractive approach in these people who are likely to be highly motivated. Neither of these approaches have been adequately evaluated at the present time.