EFFECT OF NICOTINIC-ACID ON ZINC AND IRON-METABOLISM

Nicotinic acid has functional groups capable of forming complexes with trace metals. The present study examines the effect of nicotinic acid supplementation on absorption and utilization of zinc and iron. In vi tro zinc uptake by human erythrocytes was studied using blood samples of 10 healthy subjects. It was found that 8 mu moles nicotinic acid or NADP increased Zn-65 uptake by 38.9% and 43.1% in fasting, and by 70. 9% and 28.1% in postprandial conditions. In animal experiments, nicoti nic acid supplementation to finger millet based diet resulted in signi ficant enhancement of percent zinc absorption, liver zinc and growth o f weanling mice (P < 0.05). When mice were fed with nicotinic acid-def icient, -adequate and -excess synthetic diets for four weeks it was ob served that, in comparison with the nicotinic acid-deficient diet, per cent zinc absorption, intestinal zinc, percent haeomoglobin and liver iron increased significantly under nicotinic acid-adequate and -excess conditions. The results obtained suggested that nicotinic acid, in ad dition to its known effect on growth and metabolism, may be playing an important role in enhancing zinc and iron utilization.