What is the role of niacin (vitamin B3) in my body?

Vitamin B3, or niacin, is involved in chemical reactions that provide your cells with the energy they need for normal metabolism. It's essential to the good health of your skin, digestive system and nervous system. A vitamin B3 deficiency can lead to a condition known as pellagra, which causes a red rash on the skin, vomiting and diarrhea, or nervous system problems including headache, fatigue and memory loss.

Niacin is found in many foods, including fish, chicken, red meat, nuts, whole grains and dried beans. You can also take niacin in supplements, but consult your doctor first.
Niacin is a B vitamin that helps activate over 200 enzymes, the majority of which regulate the breakdown of carbohydrates, fats and proteins, which the body then uses for energy and for keeping the nervous system, digestive system, skin, hair and eyes healthy. Most people get about twice as much niacin as they need from their diet. Cereals are fortified with niacin and are probably part of the reason that there’s no apparent niacin deficiency in the U.S. population. Deficiency still occurs in developing countries, however, causing pellagra -- which is characterized by gastrointestinal problems, skin rashes and mental disorders.

Brain Health

Niacin may help reduce the risk of Alzheimer’s disease. A Rush Institute for Healthy Aging study found that people in the top fifth of niacin intake had an 80 percent lower risk of developing Alzheimer’s, with the risk reduction stronger for food sources of niacin, as opposed to those who took it in its supplement form.

Heart Health

Some doctors prescribe high dosages of niacin to lower LDL (bad) cholesterol and increase HDL (good) cholesterol. Unfortunately, the dose needed to have an effect is 30 to 100 times the amount of niacin you get from foods, and is high enough to cause side effects and even liver problems.
Michael T. Murray, ND
Naturopathic Medicine
Since niacin, or vitamin B3, can be made in the body by the conversion of tryptophan, many nutritionists do not consider niacin an essential nutrient as long as trytophan intake is adequate. Niacin functions in the body as a component in the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which are involved in over fifty different chemical reactions in the body. These niacin-containing coenzymes play an important role in energy production; fat, cholesterol, and carbohydrate metabolism; and the manufacture of many body compounds, including sex and adrenal hormones. Niacin was discovered during the search for the cause of pellagra.
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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.