Vitamin B3

Vitamin B3, also known as niacin or nicotinic acid, is a water-soluble vitamin, used by the human body as nicotinamide (also called ‘niacinamide’) to form the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). None of the forms are related to the nicotine found in tobacco, although their names are similar (1).

The amino acid tryptophan is the precursor of niacin. Since nicotinic acid can also be synthesized in humans from the amino acid tryptophan, it does not qualify as a vitamin provided that an adequate dietary supply of tryptophan is available.

Authored by Dr Peter Engel in 2010, reviewed by Giorgio La Fata on 06.06.2017

Health functions

Vitamin B3 (niacin) contributes to the normal function of the heart, nervous system, and neurological development.

Disease risk reduction

In vitro (cell culture) studies provide evidence that vitamin B3 (niacin) coenzyme NAD content influences the cellular response to DNA damage, an important risk factor in cancer development (4, 5, 6).

Learn more

Things to know about Vitamin B3

  • Other applications

    The Coronary Drug Project (CDP) followed over 8,000 men with a history of heart attack (‘myocardial infarction’) for six years (13).

  • Intake recommendations

    The recommended dietary allowance (RDA) of vitamin B3 (niacin) is dependent on age, gender, and other factors.

  • Supply situation

    Intake data from a number of European countries indicate that average intakes of vitamin B3 (niacin) for adults (20–40 mg/day) are above those recommended (23).

  • Deficiency

    Symptoms of vitamin B3 (niacin) deficiency involve the skin, digestive and nervous system, and in severe cases can lead to pellagra.

  • Sources

    Foods high in vitamin B3 (niacin) include meat, poultry, tuna, salmon, cereal, beans, seeds, milk, green leafy vegetables, coffee, tea, and yeast.

  • Safety

    Vitamin B3 (niacin) from foods is not known to cause adverse effects. Side effects have been reported with preparations of niacin for disease treatment

  • References

    Consult the full list of scientific references.