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.