https://www.sciencedaily.com/releases/2016/10/161027122047.htm nicotinamide mononucleotide (NMN) -> NAD is once again in the news. Anti-aging effects. Note that there are previous mouse studies that show NMN rapidly converts into available NAD in vivo. Nicotinamide dinuclueotide (NAD) levels and production go down in mouse tissues as the mouse ages. Humans as well. The concept is to supplement NMN thus increasing NAD levels, which in mice has been demonstrated to have an effect. NMN is found in broccoli and some of its cruciferous companions like cabbage and brussel sprouts. Which are safe to eat. Even though you may find them revolting. Unfortunately, I would suspect NMN will become the next anti-aging "hot" supplement. A word to the wise: there are transport molecules (e.g., passenger specific lipoproteins ) that act like little shuttles to move nutrients around in the bloodstream and into cells. The transport system can be swamped by supplements. The same lipoprotein "taxi" that moves vitamin C also moves Zn and Cu. So if you take 1000mg of vitamin C, the transport system breaks down for Zn and Cu because the system is overloaded with vitamin C passengers. Over time with continued supplementation you become deficient in Cu and/or Zn. I believe this model works for larger molecules, like NMN, as well. Eat broccoli instead. BTW it has vitamin C.