Influence of age on the selenium status in Belgium and The Netherlands

Plasma selenium concentration and glutathione peroxidase activity in red blood cells were determined in subjects from different age groups. The selenium level (mean +/- SD) found in infancy (0 to 6 months) was 2 +/- 0.6 micrograms/dl, with the lowest value of 1 microgram/dl observed in a 4-month-old infant. These levels were significantly lower (p less than 0.001) than the value of 9.5 +/- 1.1 micrograms/dl found in the adult group and 7.7 +/- 1.3 micrograms/dl found in the group of older children (2 to 15 yr). Younger children (6 to 24 months of age) had intermediate levels of 5 +/- 1.2 micrograms/dl. When the data were plotted on a logarithmic scale as a function of age, the figure shows clearly that the plasma selenium levels increase steadily with age throughout life after an initial drop at 60 to 90 days. There was a satisfactory correlation between the plasma selenium concentration and the enzyme glutathione peroxidase activity in the red blood cells (Spearman's p = 0.45, p less than 0.005). Although very low selenium values were observed, the enzyme glutathione peroxidase activity remained above 10 U/g hemoglobin (with only one exception) in all patients.