For the past decade, healthcare providers have recommended that people who’ve had skin cancer take a form of vitamin B3 called nicotinamide, following a 2015 study that showed the supplement could lower the risk of new skin cancers.
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New research affirms these findings with a much larger study group.
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The new investigation found an “overall benefit for nicotinamide used to prevent skin cancer,” says study author Lee Wheless, MD, PhD, an assistant professor of dermatology at Vanderbilt University Medical Center in Nashville and a staff physician at the Tennessee Valley Health System Veterans Affairs Medical Center.
Some people getting nicotinamide especially benefited. “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,” Dr. Wheless says.
Study Saw Overall Risk of Skin Cancer Recurrence Drop by 14 Percent
The retrospective cohort study used electronic health record data from the Veterans Affairs Corporate Data Warehouse over a 25-year period. Nearly 34,000 patients who’d had skin cancer were included.
Researchers examined the outcomes of patients who took oral nicotinamide and had another skin cancer diagnosis. They compared 12,287 patients who received the supplement with 21,479 who didn’t.
They found that patients who took 500 milligrams of nicotinamide twice a day for at least 30 days had a 14 percent decrease in overall recurrence risk. Patients who took nicotinamide after their first skin cancer saw their risk drop the most — by 54 percent.
The biggest risk reduction was for patients with squamous cell carcinoma, the second most common type of skin cancer. It occurs when DNA damage triggers abnormalities in the squamous cells located near the skin’s surface.
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“Everyone in this study had a prior skin cancer, so these data can’t speak to primary prevention, but for secondary prevention, I’d say these data are pretty convincing that there is a benefit of nicotinamide for some patients,” Wheless says.
Why Could Vitamin B3 Help Prevent Skin Cancer Recurrence?
Nicotinamide, which isn’t the same as niacin (another form of B3), is believed to help repair DNA damage from ultraviolet (UV) radiation exposure and may counter the immune suppression that happens after sun damage, says Brian Zelickson, MD, a dermatologist at Schweiger Dermatology Group in Edina, Minnesota. Dr. Zelickson wasn’t involved with the study.
“Our skin is constantly exposed to UV radiation, so our DNA repair machinery is working hard to keep up,” Wheless adds. “Over time, small amounts of DNA mutations build up and can lead to skin cancer. By improving DNA repair, those mutations don’t accumulate as rapidly.”
This is likely why the latest research shows greater benefits of nicotinamide when taken after a first skin cancer rather than after multiple skin cancers. “Patients with fewer skin cancers likely have less background DNA damage, so slower accumulation leads to less risk,” Wheless says. “Patients with multiple skin cancers likely have more background DNA damage, and so it doesn’t take much more to tip the scales and develop another skin cancer.”
Study Is ‘Another High-Level Piece of Evidence’
The new research is significant because it’s “another high-level piece of evidence to show that nicotinamide does actually help reduce the risk of skin cancer,” says Anthony Rossi, MD, a dermatologist specializing in Mohs micrographic surgery and other surgeries for skin cancer at Memorial Sloan Kettering Cancer Center in New York City. Dr. Rossi wasn’t involved in the latest study.
Rossi says he regularly recommends nicotinamide to his patients to help lower their risk of subsequent skin cancers.
While there are no treatment guidelines for using nicotinamide to prevent skin cancer, Wheless says the new study provides “some pretty strong evidence that we should be considering its use earlier in our skin cancer patients.”
Should You Take a Vitamin B3 Supplement if You’ve Had Skin Cancer?
Nicotinamide is inexpensive, well-tolerated, and adds another layer of protection for patients who’ve had skin cancer, Zelickson says.
“It won’t replace sunscreen, hats, or skin checks, but it’s a smart supplement in the right context,” he says. “For high-risk patients, especially after a first skin cancer, B3 can make a meaningful difference.”
The recommended dosage is 500 milligrams twice a day, Rossi says.
Importantly, those taking the vitamin shouldn’t neglect other measures to protect against skin cancer, he says. The American Academy of Dermatology recommends wearing sunscreen daily with an SPF of 30 or higher, and specifically one that is broad spectrum, meaning it protects against UVA and UVB rays.
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The Study Has Limitations
The study population was limited to a Veterans Affairs population who were mostly white males, and researchers noted that the population is “not necessarily generalizable.”
“Veterans are a special population that we know is at higher risk of skin cancer compared to the civilian population,” Wheless says. “I would love to see this replicated in a broader population to confirm.”
As an observational study, the researchers said there could be some unmeasured variables. For instance, some patients could have received nicotinamide over the counter or from a non–Veterans Affairs dermatologist.
“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,” Wheless says.
He and his team are developing a prospective trial to address some of these limitations.
