In some metabolic reactions it is NAD which is the needed catalyst, with NADH a useful by-product, in other reactions the situation is reversed. NAD and NADH also serve to activate various enzymes, NAD for example, activates alcohol dehydrogenase and acetaldehyde dehydrogenase that are the two enzymes needed to detoxify the alcohol we drink into carbon dioxide and water. NADH is the first of five enzyme complexes of the electron transport chain, where much of the ATP bioenergy that runs every biological process of our lives is formed. Each unit of NADH is capable of generating three units of ATP energy. NAD, known biologically as coenzyme 1, is found in every cell in the human body, where it plays an important role in energy production in the cells.
Cells require energy in order to perform their cellular processes efficiently.
NAD is the 'spark' which drives this process, known as cellular respiration. A total of 10 NAD is required for this process. Any deficiency in NAD molecules reduces the cellular energy output significantly. Energy is constantly driving every cell in the human body. NAD's involvement in the brain, central nervous system and muscles, where it not only aids in producing cellular energy, but also stimulates production of the neurotransmitters, Dopamine, Noradrenaline and Serotonin.