Ageing is associated with impaired immune responses and inversed in faction- related morbidity. This study assessed the effect of physiological amounts of vitamins and trace elements on immune competence and occurrence of infection- related illness. 96 independently living, healthy elderly individuals were randomly assigned to receive nutrient supplementation or placebo. Nutrient status and immunological variables were assessed at baseline and at 12 months, and the frequency of illness due to infection was ascertained. Subjects in the supplement group had higher numbers of certain T-cell subsets and natural killer cells, enhanced proliferation response to mitoses, increased interleukin-2 production, and higher antibody response and natural killer cell activity. These subjects were less likely than those in the placebo group to have illness due to infections (mean [SD] 23 [5] cuss 48 [7] days per year, p=0.02). Supplementation with a modest physiological amount micronutrients improves immunity and decreases the risk of infection in old age.

Ageing is generally associated with impaired immune response and increased frequency of infection (especially respiratory disease) which is a major cause of illness and the fourth commonest cause of death in elderly people. However, at least 25% of old individuals have immune responses as vigorous as those of young adults. Nutrition is an important determinant of immunocompetence. Protein-energy malnutrition and deficiencies of various nutrients impair several immune responses, especially cell-mediated immunity and nutritional disorders are common in old age supplementation with selected nutrients may improve certain aspects of the immune system. However, in previous studies the numbers of subjects has been small large pharmacological closes of single nutrient or a few nutrients were used, and the duration of supplementation and follow-up was limited. The use of a single nutrient in large closes may lead to secondary alterations in requirements,, to malabsorption of other nutrients, and in some instances, to impaired immune responses. For example, Payette and colleagues showed that high dietary intakes of vitamins E and D were associated with decreased activity of interlcukin-2. Most importantly morbidity has not been evaluated systematically. In this report the hypothesis tested is that an optimum intake of all essential micronutrients in physiological amounts will results in improvement immune responses and reduces the frequency of infection in old age.More....