Niacin is the general term for vitamin B3, as it can occur in several forms including nicotinic acid, niacinamide, and nicotinamide, the latter of which we think is the best form to use in supplements. Niacin is usually obtained from the diet from high protein foods such as meat, fish and nuts. Niacin contributes to the normal function of the nervous system, as well as to the maintenance of normal skin and mucous membranes. Like many of the B vitamins it is also involved in the metabolic processes that release energy from food. Suitable for vegetarian.