Nicotinamide

Nicotinamide, (/ˌnɪkəˈtɪnəmaɪd/) also known as niacinamide, NAA, and nicotinic amide, is the amide of nicotinic acid (vitamin B₃ / niacin). Nicotinamide is a water-soluble vitamin and is part of the vitamin B group. Nicotinic acid, also known as niacin, is converted to nicotinamide in vivo, and, though the two are identical in their vitamin functions, nicotinamide does not have the same pharmacological and toxic effects of niacin, which occur incidental to niacin's conversion. Thus nicotinamide does not reduce cholesterol or cause flushing, although nicotinamide may be toxic to the liver at doses exceeding 3 g/day for adults. In cells, niacin is incorporated into nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), although the pathways for nicotinic acid amide and nicotinic acid are very similar. NAD+ and NADP+ are coenzymes in a wide variety of enzymatic oxidation-reduction reactions. Commercial production of niacin and niacinamide (several thousand tons annually) is by hydrolysis or aminolysis of 3-cyanopyridine (nicotinonitrile).