What is niacin?

Niacin, also called nicotinic acid, is a B vitamin that is used by the body to turn food into energy. Niacin also helps keep the nervous system, digestive system, and skin healthy. That's why niacin is often a part of a daily multivitamin, though most people get enough niacin from the food they eat.

When it's used as a treatment to improve cholesterol numbers or correct a vitamin deficiency, niacin is sold in higher doses available by prescription.

Niacin also is available as a supplement that can be bought without a prescription. These supplements are not regulated like prescription medicines. The ingredients, formulations, and effects of niacin supplements can vary widely.

Talk with your healthcare professional before you take niacin because it can cause serious side effects in high doses.