A large U.S. veterans study confirms that nicotinamide, a form of vitamin B3, reduces the risk of new skin cancers. Researchers analyzed 33,833 patients taking 500 mg twice daily for over 30 days versus non-users.
Overall, nicotinamide lowered the risk of basal cell carcinoma and squamous cell carcinoma by 14%. The benefit was strongest—about 54% reduction—for those who began the supplement after their first skin cancer diagnosis, especially for squamous cell carcinoma. Starting nicotinamide after multiple cancers had already developed provided smaller protection.
In 1,334 immunocompromised organ transplant recipients, overall risk reduction was not statistically significant, but early use still decreased squamous cell carcinoma cases. These results support recommending nicotinamide early for patients at risk, rather than waiting for multiple cancers to occur.