Nicotinic acid assay in blood and urine.

ICOTINIC ACID and its derivatives occur in biologic materials as nicotinic acid, as nicotinamide, and in two co-enzymatic forms: diphosphopyridine nucleotide (DPN), and triphosphopyridine nucleotide (TPN). Among mammals, only man and dog are known to develop syrnptoms of nicotinic acid deficiency. In man, deficiency results in dermatitis, diarrhea, delirium, and death. Recently, nicotinic acid has been found to lower serum cholesterol levels in hypercholesteremic and normal persons (1) and to diminish atheromatous plaques in rabbits (2). Because of the renewed clinical interest in nicotinic acid, a more specific and sensitive assay for nicotinic acid than those described (3-6) is warranted.