what does nad do

NAD, or Nicotinamide Adenine Dinucleotide, is a vital molecule found in all living cells that plays a crucial role in cellular energy production, metabolism, and repair. It acts as a coenzyme facilitating redox reactions by transferring electrons between molecules. NAD exists in two forms: NAD+ (oxidized) and NADH (reduced); this cycle is critical for generating ATP, the main energy currency in cells. Beyond energy metabolism, NAD+ is also essential for DNA repair, cellular aging regulation, immune function, and enzyme activities linked to longevity and health maintenance. Its levels decline with age, which is associated with age-related diseases, making it a focus of anti-aging and therapeutic research.