A commonly available supplement may help reduce non-melanoma skin cancers, new research suggests. A JAMA Dermatology study of more than 33,000 U.S. veterans found that use of nicotinamide (a form of vitamin B3) was associated with fewer cases of non‑melanoma skin cancers compared with nonuse. Overall, the supplement was linked to a 14% reduction in future skin cancers, with the largest benefit seen in people who began nicotinamide after their first skin cancer diagnosis—whose risk of another cancer dropped by more than half.
These findings build on a 2015 randomized clinical trial of 386 participants that reported fewer new skin cancers among those taking nicotinamide. The larger observational study strengthens evidence from real‑world data that nicotinamide may have a protective effect against UV‑related skin cancers.
Dermatologists say the biologic rationale is plausible. Nicotinamide replenishes cellular energy molecules (NAD+ and ATP) used in DNA repair, helping skin cells repair UV‑induced damage more efficiently. It also appears to preserve local immune surveillance in the skin and reduce inflammation—mechanisms that could lower the chance that UV‑damaged cells survive and progress to cancer.
However, the study has limitations. It was retrospective, so unmeasured confounders—such as sun exposure habits, medication adherence, and differences in dermatology follow‑up—could influence results. The veteran cohort was older and predominantly male, which limits generalizability. Exposure assessment relied on prescription and record data rather than direct adherence measures, and benefits were less clear in some groups (for example, certain immunosuppressed or solid‑organ transplant patients).
Clinicians emphasize that nicotinamide should be considered an adjunct, not a replacement, for established prevention measures. Regular sun protection—daily broad‑spectrum sunscreen (SPF 30 or higher), protective clothing and hats, avoiding peak sun hours, and routine skin checks—remains the cornerstone of prevention. For people at higher risk or with a prior skin cancer, nicotinamide may provide an additional internal layer of protection by supporting DNA repair and reducing inflammation.
When recommended, the studied dose is 500 mg twice daily, and consistent, ongoing use is important to potentially see benefit. Patients should discuss individual risk factors, medications, and overall health with their doctor before starting nicotinamide. Regular self‑exams and prompt evaluation by a dermatologist for any new, changing, or symptomatic spots remain essential because early detection improves outcomes.
