Nicotinamide adenine dinucleotide (NAD+) is a molecule required for the chemical reactions that produce cellular energy in the mitochondria. NAD+ is found in every living cell. In addition to aiding in cellular energy production, NAD+ plays a role in more than 500 reactions in the body, including gene expression, stress response, and DNA repair. NAD+ also helps support the tricarboxylic cycle, ꞵ-oxidation, and glycolysis. Studies have found a potential association between NAD+ insufficiency and type 2 diabetes mellitus, certain neurodegenerative disorders, cardiovascular disease, and various other age-related diseases. Recent research has also explored the potential role that NAD+ may play in supporting certain aspects of athletic performance.
A review article by Campelj and Philp investigated the current literature to determine a potential link between NAD+ and athletic performance. Skeletal muscle requires more than 100 times the amount of adenosine triphosphate (ATP) during exercise as compared to a resting state, yet ATP production does not occur at the same rate. Glycolysis and oxidative phosphorylation help the body provide compensatory ATP during exercise, featuring the conversion of NAD+. The NAD+ levels have been shown to be modulated by certain precursors including tryptophan and nicotinamide riboside (NR).
Nicotinamide riboside (NR) is a variation of vitamin B3 (niacin), and NR is a building block for NAD+. Evidence suggests that NR may help support mitochondrial function and promote healthy NAD+ status. NR may also help support certain aspects of athletic performance. In animal studies, NR administration was reported to help promote skeletal muscle NAD+ and mitochondrial biogenesis in the presence of certain muscular myopathies.
In a clinical study (n = 8) with supplementation of 1,000 mg of NR for 9 days, results indicated an increase in blood levels of NAD+ in healthy individuals. An 8-week randomized, double-blind controlled, clinical trial explored the potential impact of NR supplementation on blood NAD+ levels at varying amounts. NR as Niagen® was administered at 100 mg, 300 mg, and 1,000 mg levels. Within 2 weeks, significant increases in whole blood NAD+ levels were found to have increased by 22%, 51%, and 142%, respectively.
A randomized controlled, crossover clinical trial explored the efficacy of NR supplementation on skeletal muscle NAD+ metabolomics in older adults. Twelve individuals with a median age of 75 were randomized to either a placebo arm or a treatment arm that consisted of a daily supplementation of 1,000 mg of NR for 21 days. NR was shown to increase skeletal muscle NAD+ and decrease certain pro-inflammatory cytokines.
Another study reported increases in NAD+ precursors and metabolites after NR administration, after exercise, and 3 hours after exercise. However, more research is needed before clinical conclusions can be made. In addition, certain research questions still need to be addressed, particularly involving the potential involvement of NAD+ and its precursors in skeletal muscle metabolomics.
NAD+ and its precursor NR may help support many aspects of health. NR may help promote healthy aging, cellular health, and mitochondrial function. It may also help support certain aspects of athletic performance.
By Colleen Ambrose, ND, MAT