Nicotinamide supplementation was associated with a decreased risk for melanoma among patients with a history of other skin cancers, according to a retrospective cohort study of more than 33,000 veterans.

The study, which won a first-prize poster award at the American Academy of Dermatology (AAD) 2026 Annual Meeting, “suggests that nicotinamide could potentially be effective for primary prevention of melanoma among patients who have had a prior nonmelanoma skin cancer,” noted Lee Wheless, MD, PhD, one of the senior authors, an assistant professor of dermatology at Vanderbilt University and a staff physician with the Tennessee Valley Healthcare System VA Medical Center, both in Nashville, Tennessee.

The effect of nicotinamide, at a dose of 500 mg twice daily, was statistically significant for invasive, but not in situ, melanoma, and it was consistent in both sun-exposed and sun-protected areas, he told Medscape Medical News.

The retrospective cohort study used data from the Veterans Affairs (VA) Corporate Data Warehouse from January 1, 2007, to December 31, 2024. It included a total of 33,581 patients with one or more prior skin cancers of any type. The cohort was predominantly White and men, with comparable mean ages (77.5 years in the exposed group vs 77.1 years in the unexposed group).

The US Department of VA offers nicotinamide, a vitamin B₃ derivative, on formulary. Patients exposed to nicotinamide 500 mg twice daily were propensity score matched to unexposed patients based on “numerous skin cancer risk variables to make sure risks at specific timepoints in the patients’ lives matched up,” explained Wheless.

Baseline matching variables included age, sex, race, age at first skin cancer, number and year(s) of prior skin cancers of any type, number of dermatology visits after baseline, chronic lymphocytic leukemia, solid organ transplantation, exposure to acitretin, and field therapy.

Stratified Cox proportional hazards models showed that, overall, among all patients with a history of skin cancer, nicotinamide supplementation was associated with a 33% reduction in the rate of melanoma development (hazard ratio [HR], 0.67; 95% CI, 0.57-0.79). The risk reduction was greater among patients with no prior melanoma (HR, 0.64; 95% CI, 0.52-0.78; P < .001), but it was not significant in those with prior melanoma (HR, 0.90; 95% CI, 0.48-1.69).

When asked if the findings support a protective effect of nicotinamide in healthy people without any history of skin cancer, Wheless said a very large study would be needed to determine that. “I have recommended it to some very high-risk sun-damaged patients with precancerous lesions, as they may benefit, but not to patients with few risks for skin cancer otherwise,” he said.

The study findings support prior evidence that “the earlier we start skin cancer patients on nicotinamide, the more protection we get against future skin cancers,” commented Sarah Aaron, MD, a dermatologic surgeon with Palo Alto Foundation Medical Group in Palo Alto, California, who was not involved in the research.

She referenced a previous study by the same group, using the same cohort, showing nicotinamide was linked to a reduction in nonmelanoma skin cancers.

“The data for nonmelanoma skin cancer are well known, though when we first learned of the benefit approximately 10 years ago, it was difficult for patients to find high-dose nicotinamide in local drugstores,” she told Medscape Medical News. “Now it is much easier to find online or at larger pharmacies [and] is also included in some supplements designed for skin health.”

Yet despite awareness among dermatologists, she said there may be still a barrier when it comes to counseling their patients. “Dermatologists are pressed to complete a full skin cancer screening and counseling in a brief visit,” she said.

“As a Mohs surgeon, I have more time to chat with patients during their procedures, so I have taken that time to share data with my patients. I also include information about it on my post-care handouts, so that patients are armed with the right questions when they return to their primary dermatologist,” she said.

Wheless and another senior author of the study reported receiving support from the Department of Defense and/or the Department of VA. The other authors had no relationships to disclose.

Aaron reported being a speaker for Regeneron and Castle Biosciences; and being a consultant for Castle Biosciences, Enspectra Health, Lumenis, Regeneron, and Replimune. In addition, she reported being an unpaid ambassador for Harken Derm, which makes sunscreen and a sun and eye health supplement that includes nicotinamide as one of the ingredients.

Kate Johnson is a Montreal-based freelance medical journalist who has been writing for more than 30 years about all areas of medicine.