Metabolism of niacin

The physiologically active forms of niacin are nicotinic acid, nicotinamide, and their coenzymes (93,96). Niacytin and the niacynogens appear to have limited bioavailability, although more work is needed in this area. The absorption and metabolism of niacin has been reviewed (20,93). 

K Shibata. The metabolism of niacin in each organ and the biological method for assessing the nutritional status of niacin in the rats. Vitamins (Japan) 61 39-56, 1987. 

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