Oral nicotinamide (NAM) supplementation has been shown to decrease the incidence of keratinocyte carcinoma (KC) in high-risk skin cancer patients. NAM is a nicotinamide adenine dinucleotide (NAD+) intermediate and thus directly leads to increased NAD+. This increase in NAD+ is believed to be responsible for NAM’s impact on keratinocyte carcinoma risk. NAD+ has protective cellular effects and is a necessary cofactor for DNA repair, helping to prevent potentially oncogenic mutations. Nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are NAD+ intermediates like NAM...