Effects of trace element and/or vitamin supplementation on vitamin and mineral status, free radical metabolism and immunological markers in elderly long term-hospitalized subjects. Geriatric Network MIN. VIT. AOX

Abstract

A randomized double-blind trial was performed in order to assess the efficacity of differing combinations of antioxidant nutrients on biochemical parameters of vitamin and trace element status, immunological parameters and free radical metabolism in elderly long term hospitalized subjects. A total of 756 institutionalized elderly subjects were recruited in 26 nursing homes in different areas of France. Four groups were constituted, receiving daily, for 1 year, either vitamins (beta-carotene, 6 mg; vitamin C, 120 mg; and vitamin E, 15 mg), trace elements (zinc, 20 mg and selenium, 100 micrograms), trace elements associated with vitamins, or a placebo. Biochemical indicators of trace elements and vitamin status and free radical parameters were measured before and after 6 months and 1 year of supplementation. Some immunological markers were investigated initially and after 6 months of supplementation on a subsample of 134 subjects. Mean plasma levels of alpha-tocopherol, gamma-tocopherol, vitamin C, alpha-carotene, beta-carotene and copper increased significantly after 6 months of supplementation in groups receiving vitamins alone or associated with trace elements. Serum selenium concentrations were significantly increased at 6 months of supplementation, and serum zinc only after one year in the trace element groups. Serum lycopene levels were significantly decreased by trace element supplementation. A significant increase in Se-glutathione peroxidase (GPx) levels was observed in groups receiving trace elements alone or associated with vitamins. No effect was noted on superoxide dismutase (SOD) activity or TBARs production. No effect of supplementation was found for in vitro lymphocyte proliferative responses or most lymphocyte subsets, except for a significantly lower percentage of CD2 subsets observed in groups receiving mineral supplementation either alone or associated with vitamins. A significant difference in CD19 subsets was found in groups receiving trace elements. Mean IL-1 production was significantly higher after 6 months of supplementation in the vitamin groups.