Nicotinamide adenine dinucleotide (NAD+) is an important coenzyme that participates in various energy metabolism pathways. NAD+ regulates energy metabolism, DNA damage repair, gene expression, and stress response through these enzymes. Numerous studies have shown that NAD+ levels decrease with aging and under disturbed nutrient conditions, such as obesity. Additionally, a decline in NAD+ levels is closely related to the development of various metabolic disorders, including diabetes and fatty liver disease. In addition, many studies have revealed that administration of NAD+ precursors, such as nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), efficiently increase NAD+ levels in various tissues and prevent such metabolic diseases.[2]

According to the Journal of Diabetes Investigation, researchers have found the nicotinamide catabolic cascade might play an important role, especially in oxidative stress production and epigenetic change in diabetes.

Several research groups used the precursors of NAD+ to improve insulin resistance due to obesity. The effect of NAD precursors is mainly through the enhancement of sirtuin pathways.[2]

Recently, a research group examined the effect of long-term administration of NAM in mice. The administration of NAM restored some aging-related metabolic decline including increased protein carbonylation and the reduction of oxygen consumption rates. Consequently, NAM administration ameliorates glucose tolerance during diet-induced obesity.[2]