Liver, chicken, beef, fish, seeds, peanuts, brown rice.

Niacin (or vitamin B₃) is a water-soluble vitamin that is part of the vitamin B complex; it is also known as nicotinic acid and nicotinamide. These names suggest a connection with the nicotine found in tobacco, but there is no link. The body can also produce niacin from the amino acid tryptophan.

Niacin is a component of many important coenzymes that are involved in the building and breaking down of carbohydrates, amino acids and fatty acids. It is also involved in the production of nucleotides as building blocks for DNA and RNA.