The precursors of nicotinamide coenzymes mainly include tryptophan (Trp), nicotinic acid (NA), nicotinamide, nicotinamide mononucleotide (NMN), and nicotinamide ribose (NR). These compounds not only have an impact on pellagra but also show potential therapeutic effects in other diseases. Currently, NR has been developed as a dietary ingredient and used as an additive in nutritional supplements and pharmaceutical compositions. Moreover, increasing studies have found wider applications of NR supplements in medical research. Additionally, NMN shows promising prospects for treating aging-related diseases like diabetes and Alzheimer disease. Henceforth, conducting comprehensive, systematic, and scientific preclinical and clinical research based on this foundation is crucial for the future development of drugs related to NR and NMN.