Iron deficiency reduces the efficacy of tryptophan as a niacin precursor

Iron deficiency impairs body converting tryptophan to niacin. Chicks fed the iron-deficient diets had markedly lower hemoglobin concentrations than those fed the iron-adequate diets. Regardless of iron level, chicks had linear growth responses to either nicotinic acid or tryptophan supplementation. Low bio-available iron contributes to niacin deficiency in populations.