Abstract
Nicotinamide adenine dinucleotide (NAD+) is present in all living cells and is a central signaling molecule and enzyme cofactor that is involved in many fundamental biological processes, including energy production, DNA repair, gene expression, and calcium-dependent signaling. It is known that NAD+ levels decrease in many pathological conditions, as well as with age in many tissues of rodents and humans, which contributes to the development of age-related pathology. There is evidence that an increase in intracellular NAD+ levels prevents the development of various pathological conditions. The review presents an analysis of modern data on the possibility of using precursors of NAD+ biosynthesis to provide the required level in body tissues in order to correct various disorders of vital functions.