Vitamin B3, or niacin, is essential in small amounts for normal body function. The skin, nerves, and digestive system all require vitamin B3. Research has examined nicotinamide, a form of vitamin B3, for preventing nonmelanoma skin cancers, though findings are inconsistent.
One study published in 2015 showed a chemopreventive value of vitamin B3 supplementation. In this phase 3 clinical trial, which enrolled nearly 400 patients at high risk of developing skin cancer, half of the participants received an intervention of 500 milligrams of nicotinamide twice daily for one year. The other half of the participants received a placebo on the same schedule. All participants had dermatology visits every three months for evaluations for non-melanoma skin cancers, including basal-cell carcinomas and squamous-cell carcinomas. The researchers reported a 23% reduction in the rate of new non-melanoma skin cancers among participants in the vitamin B3 supplement group compared with the placebo group.
In 2023, a meta-analysis of 225 published studies identified four that provided sufficient information to estimate the risk of developing non-melanoma skin cancer among participants taking nicotinamide. These researchers found no association between nicotinamide intake and the risk of developing either basal-cell or squamous-cell carcinoma. This study concluded that, at the time, sufficient data did not exist to suggest that nicotinamide reduced the number of non-melanoma skin cancers.
However, the most recent study investigating the link between nicotinamide and skin cancer, published earlier this year, looked retrospectively at over 30,000 veterans to evaluate the impact of vitamin B3 on skin cancer prevention. The researchers identified 12,287 patients who were exposed to 500 milligrams twice daily for more than 30 days and then matched them with 21,479 unexposed patients. This study reported a decreased risk of skin cancer for the patients taking vitamin B3. Further, this study showed that starting vitamin B3 supplementation after a first skin cancer diagnosis had the most impact on preventing additional skin cancer development.
Studying vitamin B3’s effect on nonmelanoma skin cancers is challenging due to their slow development. Since these cancers often take years to appear, effective nicotinamide interventions may require long-term use. However, published studies have used intervention periods from 30 days to one year.
Sources: NEJM, JAMA Dermatol, Nutrients
