Niacin, New RDA* 16 mg NE
There are two forms of niacin: nicotinic acid and nicotinamide, and both are found in food.
Niacin is a water-soluble vitamin, which means you need it in your diet every day because it can't be stored in the body.
Free nicotinic acid and nicotinamide are present in nature in only small amounts. Nicotinic acid is mainly bound to macromolecules in plants, while nicotinamide is usually a component of NADP in the animal world.
Nicotinic acid can be formed in humans from the metabolism of dietary tryptophan, and so niacin is not really a vitamin providing adequate tryptophan is available.
*Sourced from EFSA WEBSITE