Vitamin C supplementation of old people with low blood levels.

Ascorbic acid blood levels were estimated in 828 elderly people living in the community. 297 subjects with low blood levels were admitted to a 2-year controlled trial of vitamin C. Despite a rise in plasma and leucocyte levels, vitamin C produced no apparent benefit in terms of mortality, morbidity or mental senescence. On following up all those who were originally seen, it was found that a higher proportion of deaths occurred among subjects whose leucocyte levels were below 15 mug/10(8) cells than among the rest. This association was especially marked in the men; it was not due to smoking and was probably attributable to an effect of ill-health on blood levels, either directly or through impairment of appetite.