Comparison of two levels of vitamin C supplementation on antioxidant vitamin status in elderly institutionalized subjects.

The concentrations of antioxidant vitamins, particularly vitamin C, are often low in the plasma of institutionalized elderly subjects, and could explain their susceptibility to oxidative stress. However, as such low levels were not always found in home-living healthy elderly persons, the antioxidant vitamin depletion in the formers could result from environmental conditions better than aging itself. The objective of this study was therefore to verify the antioxidant vitamin status in institutionalized elderly persons and to evaluate if a low vit C supplement could be sufficient to improve the plasma vit C concentration in those subjects. This study confirms that plasma vitamin C levels are in the scurvy range in 20 elderly institutionalized subjects and significantly lower than in healthy home-living elderly persons. Beta-carotene concentrations were found marginally low but alpha-tocopherol levels were in the normal range. All three vitamins were correlated. Fifteen days on a physiological vitamin C (150 mg/day) supplementation was sufficient to restore normal vit C levels (50 mumol/l). A further pharmacological vit C administration (750 mg/day) during 30 days only allowed a marginal increase in the plasma vit C concentrations.