Niacin, also known as vitamin B3, belongs to the B-complex family of vitamins. It exists in two related forms within the body: nicotinic acid or niacinamide. Since niacin is water-soluble, like other B-vitamins and vitamin C, the body doesn’t store it significantly and requires daily dietary intake. The body can produce small amounts of niacin from the amino acid tryptophan, found in protein-containing foods. Niacin serves as coenzymes NAD and NADP, which play crucial roles in energy production from nutrients and the synthesis of biomolecules. The liver uptakes niacin and converts it into these coenzymes, with any excess being excreted by the kidneys through urine.