Vitamin B3 forms as precursors to NAD plus : Are they safe?

Background: The oxidized form of cellular nicotinamide adenine dinucleotide (NAD +) is implicated in longevity, health improvement and even attenuation of some neurodegenerative processes. Immense interest of the public for anti-aging strategies and health-promoting lifestyle may result in increased use of NAD + precursors as food supplements. Scope and approach: Moderate by-effects, like flushing, may have limited supplementation with some B3 precursors so far. Nicotinamide riboside, which causes no flushing, has been recently granted Generally Recognised as Safe status by the US Food and Drug Administration. Here we review the safety data on the vitamin B3 precursors as supplements. Key findings and conclusion: The data for some NAD + precursor forms are scarce. Safety levels were estimated by extrapolating the experimental data. As the effects of NAD + are through the regulators of DNA repair, stress responses and energy metabolism, it seems worthwile to test the NAD + supplemments in a manner similar to drug development.