Vitamin B3 has been shown to have protective effects against damage caused by UV radiation and to reduce the rate of new premalignant actinic keratoses ^[1]. In this study, it was a phase 3, double-blind, randomized, controlled trial, where participants who had already had nonmelanoma skin cancers received 500mg of nicotinamide (B3) twice daily or placebo for 12 months. They were evaluated by dermatologists. The results showed that oral nicotinamide was safe and effective in reducing the rates of new nonmelanoma skin cancers and actinic keratoses in high-risk patients by as much as 23%. Vitamin B3 also was safe compared to placebo.