Both nicotinamide and nicotinic acid are stable when exposed to heat, light, air and alkali. Little loss occurs in the cooking and storage of foods. Principal function Niacin is involved in reactions that generate energy in tissues by the biochemical conversion of carbohydrates, fats and proteins. The two coenzymes, NAD and NADP, are essential for utilizing the metabolic energy of foods. Niacin is essential for growth and is involved in the synthesis of hormones.
Principal antagonists Copper deficiency can inhibit the conversion of tryptophan to niacin.
The pathway from tryptophan to niacin is sensitive to a variety of nutritional alterations. The most important of these, vitamin B 6 deficiency, reduces the synthesis of niacin from tryptophan. Frank deficiency Pellagra is a disease resulting from a combined deficiency of niacin and tryptophan. The symptoms of pellagra include dermatosis, dementia, diarrhoea and nervous disorders. Dermal lesions are most frequently found at sites of irritation such as the wrists, elbows and neck.