Cellular immune responses to vitamin C supplementation in ageing humans assessed by the in vitro leucocyte migration inhibition test

Ageing is associated with a greater susceptibility to progressive senescence of the immune system. We have determined the effect of dietary supplementation with vitamin C (200 mg/day for 30, 60 and 90 days) on immune responses in young (20 to 30 years old) and older people (above 60 years old). The leucocyte count, neutrophils, lymphocytes, absolute neutrophil and lymphocyte numbers and leucocyte ascorbic acid were significantly lower, whereas leucocyte migration inhibition was significantly higher, in older individuals than in young ones. Supplementation with vitamin C enhanced immunocompetent cells and the ascorbic acid concentration in leucocytes, and suppressed leucocyte migration in older individuals.