NAD+ (nicotinamide adenine dinucleotide) is a vital coenzyme found in all living cells that plays a central role in energy production, DNA repair, and overall cell health. It acts as a critical partner for enzymes involved in metabolism, helping to generate ATP, the body's main energy currency. NAD+ is also essential for a group of enzymes called sirtuins, which regulate gene expression, protein stability, and immune responses. As we age, or with inflammation and DNA damage, NAD+ levels can decline, potentially impacting cellular function. Supplementing with NAD+ precursors, along with practices like exercise and fasting, can help restore NAD+ levels, promoting cellular resilience and metabolic balance.