Niacin, also known as vitamin B3, is an essential water-soluble vitamin that plays a crucial role in human health. It is involved in various metabolic processes, particularly in the conversion of carbohydrates, fats, and proteins into energy. Niacin helps maintain healthy skin, supports the functioning of the nervous system, and is vital for the synthesis of DNA. Additionally, it acts as a precursor to important coenzymes, such as NAD and NADP, which are essential for cellular respiration and the metabolism of food.
Dietary sources of niacin include meat, fish, poultry, whole grains, legumes, and nuts. While it's possible to obtain adequate amounts through diet, niacin can also be synthesized in the body from the amino acid tryptophan, found in protein-rich foods. Niacin is sometimes used in higher doses as a therapeutic agent to help improve cholesterol levels and reduce the risk of heart disease. However, excessive intake may lead to side effects, including skin flushing and gastrointestinal discomfort. For most people, maintaining a well-balanced diet should provide sufficient niacin levels to support overall health.