Nicotinamide has shown potential as a safe and effective intervention for the 
prevention of malignant and premalignant skin lesions. Recent studies have shown 
that nicotinamide, in both oral and topical forms, is able to prevent 
ultraviolet-induced immunosuppression in humans [1,2,3] and mice [4,5]. 
Immunosuppression is a known factor for the progression of premalignant lesions, 
such as actinic keratosis [6]. Murine studies have shown that nicotinamide is 
also able to protect against photocarcinogenesis [4,5]. Preliminary human 
studies suggest that nicotinamide may help prevent skin cancers and enhance the 
regression of actinic keratoses.