Revitalize Your Body with Nicotinamide Riboside

Nicotinamide riboside (NR) is widely used as a dietary supplement. Structurally, it is a form of vitamin B3 (nicotinic acid, niacin, NA), incorporating into its structure more elements of nicotinamide adenine dinucleotide (in its oxidized form, NAD+) [1]. NR influences, in particular, energy metabolism and neuroprotection [2,3,4].
 

From a non-medical perspective, as a part of the NAD+ cofactor, NR is also inferred to be a vestige of the “ribonucleic acid (RNA) world” [5], an episode of life on early Earth where RNA was the only encoded component of both metabolism and genetics. This inference is supported by the ubiquity of NAD+ in all branches of the tree of modern life [6].
 

NR is, however, a rather reactive molecule. Its glycosidic bond joins a positively charged pyridinium heterocycle to a carbohydrate. This bond is therefore especially unstable to cleavage, making NR difficult to synthesize, store, and transport. This creates broad utility for any method to synthesize NR, as well as broad utility for derivatives of NR that are more stable.
 

Stable forms of NR are especially important today. In July 2013, NR became accessible in dietary supplements in the form of NR chloride (NRCl). This is sold and widely consumed as a dietary supplement under various trademarks, including Tru Niagen™ and Niagen® (produced by ChromaDex, Los Angeles, CA, USA). Other products containing NRCl have been commercially available [7,8]. Interestingly, analysis of some of these products at various times has shown that they do not contain pure NR but also products undoubtedly arising from the reactivity of NR.
 

Notwithstanding, commercial NR products are suggested to elevate the level of NAD+ in those who consume it [8]. Studies report that chronic NR supplementation (NRS) is well tolerated and elevates NAD+ in healthy middle-aged and older adults [2,3]. Other studies suggest NR oral bioavailability in mice and humans [9]. NR as a dietary supplement has also been the target of clinical studies [2,3]. These have proven its effect of boosting NAD+ in its consumers [8,10]. These facts make it timely to review the current state of the art.