To investigate the relationships between aging and selenium status, vitamins A and E, and plasma and erythrocyte fatty acids, we studied 105 healthy subjects (53 women, 52 men) living in Nove, a village near Vicenza (Veneto Region, northern Italy). The subjects were distributed equally for age and sex into four groups: group 1, 20-39 y; group 2, 40-59 y; group 3, 60-75 y; and group 4, > 75 y. A careful selection of subjects to exclude those with chronic or acute diseases was obtained with the collaboration of the three general practitioners operating in Nove. Aging was associated with a progressive decrease in selenium status and in the ratio of plasma and erythrocyte polyunsaturated to saturated fatty acids (P:S). Stepwise multiple linear analysis revealed age, vitamin A, and n-6 polyunsaturated fatty acids (PUFAs) as useful predictors of a substantial proportion of the selenium variability (R = 0.618, R2 = 0.382; P < 0.001) and age and erythrocyte oleic acid as predictors of erythrocyte glutathione peroxidase variability (R = 0.413, R2 = 0.17; P < 0.001).