Nicotinamide (a form of vitamin B3, Niacin) reduces the incidence of nonmelanoma skin cancers in high-risk adults. High risk was defined as having had 2 cases of skin cancer- either squamous cell or basal cell, in the past 5 years.

This study was done on over 400 adults in Australia, who were randomized to receive oral niacin (500 mg) or placebo twice daily for a year. During the study, the average number of new skin cancers was significantly lower with vitamin B3. Significant reductions were observed for both squamous cell and basal cell cancers. In addition, the number of actinic keratoses, which can turn cancerous, was significantly lower among niacin recipients as early as 3 months after supplementation began. Adverse events did not differ between the groups.

The authors conclude that “nicotinamide is widely accessible as an inexpensive over-the-counter vitamin supplement and presents a new chemopreventive opportunity against non-melanoma skin cancers.”