The Healthy Professional – Foundations Practice Test

Niacin is a vitamin, specifically part of the B vitamin group (vitamin B3). Vitamins are organic micronutrients required in small amounts for normal body function, unlike minerals, carbohydrates, or proteins. Niacin serves as a coenzyme in energy metabolism, helping enzymes that convert food into energy in the form of NAD and NADP. It is not a carbohydrate, protein, or mineral, so those nutrient classes don’t apply. Understanding its classification helps explain why daily intake matters and how deficiency can lead to conditions like pellagra.