Nicotinamide and Skin Cancer: New VA Data Reinforce B3 Benefits
A large Veterans Affairs study has strengthened the case that nicotinamide, a form of vitamin B3, can cut the chance of skin cancer coming back for patients who have already had it. The analysis pooled two and a half decades of electronic health records and focused on people with a prior skin cancer diagnosis. The results are practical and clear: supplements that help repair DNA damage may matter for preventing recurrence.
The research looked through the VA Corporate Data Warehouse, identifying nearly 34,000 patients with a history of skin cancer over a 25-year span. Investigators separated people who took oral nicotinamide from those who did not, then tracked who had another skin cancer diagnosis. This kind of retrospective cohort study can reveal real-world patterns across big populations.
Researchers compared 12,287 patients who received nicotinamide to 21,479 who didn’t, focusing on those who used 500 milligrams twice a day for at least 30 days. Across the whole group, taking the supplement was associated with a 14 percent drop in overall recurrence risk. The benefit was much larger when nicotinamide was started earlier in the disease course.
Patients who began nicotinamide after their first skin cancer experienced the biggest benefit, with risk falling by 54 percent compared to people who started later. The strongest effect showed up for squamous cell carcinoma, the second most common skin cancer that starts when DNA damage causes surface cell abnormalities. That pattern points to timing and background DNA damage as key factors in who benefits most.
Lee Wheless, MD, PhD, described the overall result as an “overall benefit for nicotinamide used to prevent skin cancer,” and emphasized the timing advantage. He added that “We were able to stratify patients by the number of prior skin cancers, finding that there was a much greater risk reduction, of more than 50 percent, when nicotinamide was started after the first skin cancer, compared to starting later after patients had developed multiple skin cancers.”
The likely biological explanation centers on DNA repair and immune effects. As Brian Zelickson, MD, points out, nicotinamide is believed to help repair DNA damage from ultraviolet radiation exposure and may counter the immune suppression that happens after sun damage. “Our skin is constantly exposed to UV radiation , so our DNA repair machinery is working hard to keep up,” Wheless adds, and “By improving DNA repair, those mutations don’t accumulate as rapidly.”
That mechanistic view helps explain why early intervention seems to matter. Patients with fewer prior cancers likely have less accumulated DNA damage, so improving repair buys time before another tumor emerges. Conversely, patients already saddled with multiple cancers probably have heavier DNA damage, meaning supplements alone may not be enough to prevent the next one.
Outside experts welcomed the findings as corroborating prior clinical trials. Anthony Rossi, MD, called the study “another high-level piece of evidence to show that nicotinamide does actually help reduce the risk of skin cancer,” and said he regularly recommends it to patients at risk for subsequent tumors. Those endorsements add clinical momentum to a therapy that is cheap and well tolerated.
Clinicians typically suggest 500 milligrams twice a day when nicotinamide is used for skin cancer prevention, and they stress it is an adjunct rather than a replacement for other protections. Nicotinamide should be part of a layered strategy that includes sun avoidance, protective clothing, and regular skin checks. It’s a sensible addition for high-risk patients, especially after that first skin cancer.
Daily sunscreen remains essential even for patients taking nicotinamide; experts still recommend using a broad-spectrum sunscreen with at least SPF 30. No pill replaces physical barriers and vigilance, and a combined approach gives the best chance to reduce future cancers. Nicotinamide appears to add a meaningful extra layer to that strategy.
The study has important limitations that matter for how broadly we apply the findings. The VA population is mostly white males, and the authors note the results are “not necessarily generalizable” to more diverse or civilian groups. Veterans are a distinct group with higher baseline risk for skin cancer, so replication in broader cohorts would strengthen the conclusions.
As an observational study, the work cannot fully rule out other influences, and the authors acknowledge potential unmeasured variables. For example, some patients may have bought nicotinamide over the counter or seen non-VA dermatologists, so exposure misclassification is possible. The team admits, “While we did a great job of trying to account for not just the regular risk factors but also the timing and number of prior skin cancers, there certainly could be unmeasured risk factors that contributed.”
Despite those caveats, the data build on previous randomized work and offer a clear, actionable message for clinicians and patients: consider nicotinamide as part of secondary prevention for people after their first skin cancer. Researchers are planning prospective trials to address limitations and refine who benefits most, but for now the evidence supports using a low-cost, low-risk supplement as one more tool against recurrence.
