Niacin: vitamin and antidyslipidemic drug.

Niacin is defined collectively as nicotinamide and nicotinic acid, both of which fulfill the vitamin functions of niacin carried out by the bioactive forms NAD(P). In the last few decades numerous new enzymes that consume NAD(P) as substrates have been identified. The functions of these enzymes are emerging as exciting paradigm shifts, even though they are in early stages of discovery. The recent identification of the nicotinic acid receptor has allowed distinction of the drug-like roles of nicotinic acid from its vitamin functions, specifically in modulating blood lipid levels and undesirable side effects such as skin vasodilation and the more rare hepatic toxicities. This information has led to a new strategy for drug delivery for niacin, which, if successful, could have a major impact on human health through decreasing risk for cardiovascular disease. Understanding the many other effects of niacin has much broader potential for disease intervention and treatment in numerous diseases including cancer.