The most important benefit of niacin or vitamin B3 is its ability to lower cholesterol levels and control them. Vitamin B3, also known as niacin, releases energy into the bodyâs cells, but niacin is primarily used to lower high cholesterol levels. You may get Vitamin B3 in supplement stores, but it is always sensible to buy niacin when specifically instructed by a doctor. Foods such as fish, nuts, dried grains, liver, chicken, lean red meat, whole grains, enriched refined grains and dried beans are good sources of vitamin B3.