Lymphocyte responsiveness of children supplemented with vitamin A and zinc.

We sought to determine the effect of supplementation with zinc, vitamin A, or a combination of the two on proliferation of T lymphocytes to concanavalin A (ConA), tetanus toxoid (TT), or tuberculin (PPD) of children living in a region endemic for suboptimal vitamin A and zinc intake. The children (n = 140, aged 6-13 y) were randomly assigned and supplemented with either zinc (25 mg/d), vitamin A (1500 mg RE/d), zinc + vitamin A, or placebo for 6 mo. After a baseline blood collection, subjects were boosted with diphtheria-tetanus antigen. Proliferative responsiveness of T lymphocytes to ConA and TT in each treatment group (n = 35) was not different at baseline or postsupplementation. Children supplemented with zinc + vitamin A tended to show higher proliferative responsiveness of T lymphocytes to PPD than did those treated with placebo (P = 0.08). This tendency was observed in females but not in males. Increased zinc and vitamin A intake could result in health benefits for children living in regions endemic for suboptimal micronutrient nutriture.

RCT Entities:   Population Interventions Outcomes