NR is a compound found naturally in trace amounts in milk.1 The nutrient NR has been studied in humans in the dose ranges from 100mg -1000mg per day. The current science suggests a single daily dose as low as 100mg provided a significant increase in NAD levels.2 NR has been reviewed by the FDA and granted NDI (New Dietary Ingredient) status permitting its use as a nutritional supplement.
1. Trammel, S. A. (2016). Nicotinamide riboside is a major NAD+ precursor vitamin in cow milk. Journal of Nutrition, 146(5), 957–63.
2. Trammell, S. A., Schmidt, M. S., Weidemann, B. J., Redpath, P., Jaksch, F., Dellinger, R. W., . . . Brenner, C. (2016). Nicotinamide riboside is uniquely and orally bioavailable in mice and humans. Nature Communications, 7, 12948. doi:10.1038/ncomms12948