Niacin supplements are taken to lower risks related to the heart and to reduce cholesterol levels, according to WebMD. Evidence suggests that niacin supplements reduce the risk of the hardening of the arteries. Niacin supplements may also reduce the risk of having a second heart attack.
Research suggests that niacin supplements boost good HDL cholesterol and triglyceride levels, according to WebMD. Niacin supplements may also lower bad LDL cholesterol levels. In order to be an effective cholesterol treatment, niacin must be taken in substantial doses. However, taking too much niacin poses health risks, so it is important to speak to a physician before taking niacin supplements for cholesterol.
Niacin is used to treat pellagra, which is a condition that occurs when the body lacks niacin, notes WebMD. Evidence suggests that niacin supplements may help to prevent type 1 diabetes, Alzheimer's disease, cataracts and osteoarthritis, but research is still ongoing as of 2015.
Niacin supplements may interact with certain medicines or supplements, so it is important to make a health care professional aware of other medications being taken, states WebMD. There may be initial side effects when taking niacin supplements, but they usually dissipate as time passes. Possible side effects include flushing, diarrhea and upset stomach.