LYMPHOCYTE RESPONSIVENESS OF CHILDREN SUPPLEMENTED WITH VITAMIN-A ANDZINC

We sought to determine the effect of supplementation with zinc, vitami n A, or a combination of the two on proliferation of T lymphocytes to concanavalin A (ConA), tetanus toxoid (TT), or tuberculin (PPD) of chi ldren living in a region endemic for suboptimal vitamin A and zinc int ake. The children (n = 140, aged 6-13 v) were randomly assigned and su pplemented 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, s ubjects were boosted with diptheria-tetanus antigen. Proliferative res ponsiveness 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 pl acebo (P = 0.08). This tendency was observed in females but not in mal es. Increased zinc and vitamin A intake could result in health benefit s for children living in regions endemic for suboptimal micronutrient nutriture.