Evaluation of safety and effectiveness of NAD in different clinical conditions: a systematic review.

Nicotinamide adenine dinucleotide (NAD) is an essential pyridine nucleotide cofactor that is present in cells and in several important biological processes, including oxidative phosphorylation and production of adenosine triphosphate, DNA repair, calcium-dependent secondary messenger and gene expression. The purpose of this systematic review is to examine whether the coenzyme formulae NAD and NADH are safe and effective when acting as a supplement to humans. This systematic review of randomized clinical trials performed a search in six electronic databases: PubMed, MEDLINE (), Embase, Cochrane CENTRAL (clinical trials), Web of Science, and Scopus.