Niacin Requirements and Dietary Sources

Robert Benson/Getty Images

Niacin is a member of the water-soluble family of B-complex vitamins. It's required for normal digestive function, converting the food you eat into energy and for healthy skin and nervous system function. It's also good for blood circulation, and your adrenal glands need niacin to make stress and sex hormones.

Niacin deficiency is rare in modern Western diets — it usually occurs as a consequence of alcoholism. Symptoms of a mild niacin deficiency include digestive upset, fatigue, canker sores, vomiting, and depression. Pellagra is caused by a full-blown niacin deficiency. Symptoms include mental problems, diarrhea, and sores on the skin.

The Health and Medicine Division of National Academies of Sciences, Engineering, and Medicine sets the daily dietary reference intakes for vitamins and minerals. The DRI for niacin is determined by age and sex. Women who are pregnant or breastfeeding need the largest amounts.

The DRIs are based on what an average healthy person needs — if you have any health conditions you should speak with your health care provider about your niacin requirements.

Dietary Reference Intakes


1 to 3 years: 6 milligrams per day
4 to 8 years: 8 milligrams per day
9 to 13 years: 12 milligrams per day
14+ years: 16 milligrams per day


1 to 3 years: 6 milligrams per day
4 to 8 years: 8 milligrams per day
9 to 13 years: 12 milligrams per day
14 + years: 14 milligrams per day
Women who are pregnant: 18 milligrams per day
Women who are breastfeeding: 17 milligrams per day

Niacin is found in a variety of foods including dairy products, poultry, fish, lean meats, nuts, legumes, eggs and vitamin-fortified foods. Since it's easily obtained from many different foods, most people don't need to take supplements to ensure an adequate intake.

Niacin Supplements and Cholesterol

When taken in large doses, niacin supplements may be used to reduce elevated triglyceride and LDL cholesterol (the bad kind of cholesterol) levels in the blood and to increase levels of HDL cholesterol (the good kind).

Although it's available as an over the counter supplement, taking niacin this way can cause problems with this type of niacin use, so speak to your doctor if you're thinking about taking niacin for cholesterol. Ingesting large amounts of supplemental niacin may result in liver damage, can interact with some types of medications, and might increase glucose levels in people with diabetes.

Taking niacin in large amounts will also cause an uncomfortable reaction called the niacin flush, which includes burning and itching sensations of the face and joints. It's not dangerous, but it can be frightening the first time it happens.

Due to these reactions and safety concerns, the Institute of Medicine established 35 milligrams per day as the upper tolerable intake level for adults. No matter what form of niacin is used, large doses should only be used under the supervision of a physician.

Was this page helpful?
Article Sources