Nicotinamide adenine dinucleotide (NAD+) is an essential metabolite that is reported to
decline in concentration in tissues of aged animals. Strategies to increase NAD+ availability
have shown promise in treating many conditions in rodents, including age-related
degeneration, which has in turn driven intense interest in the effects of supplements on
human health. However, many aspects of NAD+ metabolism remain poorly understood, and
human data are limited. Here, we discuss the state of the evidence for an age-related …