Beta nicotinamide adenine dinucleotide disodium is a bioactive form of nicotinic acid. Coenzyme used as hydrogenase and dehydrogenase. Nad usually acts as a hydrogen receptor, forms NADH, and then acts as a hydrogen donor in the respiratory chain. It mainly exists in living cells in reduced form (NADPH) and participates in synthetic reaction. In two forms, α- NAD and β- NAD, which is characterized by the configuration of ribosylnicotinamide bond. only β- The heterocephalin has biological activity.