We found no evidence to support antioxidant supplements for primary or secondary prevention. Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.
Effect of vitamin and trace element supplementation on immune indices in healthy elderly.
Aging is associated with a progressive decline in the immune system and a greater susceptibility to infection. This double-blind, placebo-controlled study, examined the effect of a vitamin and trace element supplement on immune responses of healthy, noninstitutionalized elderly subjects. Forty-seven subjects aged 61-79 years were randomly assigned to receive placebo or micronutrient supplementation for one year. Thirty-five individuals completed the one-year study. Immune function was assessed before and after the period of supplementation. Cell-mediated immune function assessed by the number of T cells and subsets remained constant in the supplemented group and there was a significant increase in CD57 natural killer cells. In contrast, a significant decrease in T cells, CD4 cells, and CD4: CD8 ratio was noted in the placebo group. Supplementation with micronutrients can play a crucial role in the maintenance of normal immune function in the elderly.