Serum selenium in danish Blood Bank donors.

Serum selenium concentration was determined over a full year in healthy donors from the Blood Bank at the municipal Hospital in Aarhus, Denmark. The age range of the donors, half of whom were women, was 20-60 yr. In months with even numbers, samples were obtained from women; in months with odd numbers, from men. For estimates of individual seasonal variation, a number of the laboratory's employees were observed with monthly samples throughout a full year.The mean serum selenium concentration plus minus SD was 81 ±12 μg/L for men (range, 42-145 μg/L), and 79±9 μg/L for women (range, 51-110 μg/L). This difference is statistically significant. We found no significant variation within the sexes due to age. The data on a possible seasonal variation are not conclusive, but suggest slightly lower values for late summer.Individuals appear to have fairly stable values over extended periods of time provided there are no major changes in lifestyle, selenium medication, or pregnancy.