NADH, or Nicotinamide Adenine Dinucleotide (NAD) in its reduced form, is a vital coenzyme found in all living cells. It plays a crucial role in energy production by helping convert food into energy through a process called cellular respiration. NADH carries electrons to the electron transport chain, where they are used to generate ATP, the energy currency of the cell. In addition to energy production, NADH is involved in various metabolic processes and helps maintain the balance of oxidation and reduction reactions in the body. It also supports the function of certain enzymes, making it essential for overall cellular health and vitality.