Vitamin B3 (Niacin)

Vitamin B3 comes in two basic forms-niacin (also called nicotinic acid) and niacinamide (also called nicotinamide). A variation on niacin, called inositol hexaniacinate, is also available in supplements.

The body uses vitamin B3 in the process of releasing energy from carbohydrates. It's needed to form fat from carbohydrates and to process alcohol. The niacin form of vitamin B3 also regulates cholesterol, though niacinamide does not.

RDI

20 mg

Deficiency

Deficiency causes a disease called pellagra. Common in certain parts of the world (in people consuming large quantities of corn), pellagra is characterized by scaly skin sores, diarrhea, mucosal changes, and mental symptoms (especially a schizophrenia-like dementia). It may develop after gastrointestinal diseases or alcoholism

Overdose

Large doses of niacin can cause liver damage, peptic ulcers, and skin rashes. Niacin can be used as a treatment for elevated total cholesterol levels, but should only be used with medical supervision.

Synergists

Vitamin B3 works with vitamin B1 and B2 to release energy from carbohydrates, so these vitamins should be taken together in a B-complex or multiple vitamin supplement.

Food Sources

Niacin is found in dairy products, poultry, fish, lean meats, nuts, and eggs. Legumes and enriched breads and cereals also supply some niacin.

Medicinal Purpose

Niacin is commonly used to treat high cholesterol and tryglicerides. Alcoholics are supplemented with the vitamin to help prevent or treat alcohol-induced malnutrition. Niacin is also used in combination with other B-Vitamins to treat dysmenorrhea, anxiety, bursitis, diabetes, multiple sclerosis, and is used topically to treat acne.

Niacin may decrease thyroid hormone levels.

Interactions with common drugs

Niacin reacts synergetically with statin drugs, and with tricyclic antidepressant drugs. Oral contraceptives deplete niacin.

Recent Studies and Articles

McKenney JM.

Lipid management: tools for getting to the goal.

Am J Manag Care. 2001 Aug;7(9 Suppl):S299-306. Review.

Niacin and statin drugs can be used in combination to treat high lipids.


Murray MF, Langan M, MacGregor RR.

Increased plasma tryptophan in HIV-infected patients treated with pharmacologic doses of nicotinamide.

Nutrition. 2001 Jul-Aug;17(7-8):654-6.

Recognizing that tryptophan depletion in AIDS patients was similar to tryptophan depletion caused by pellagra, the researchers treated HIV-infected patients with niacin as nicotinamide. The nicotinamide was successful in increasing the plasma tryptophan.