Doctors who perform skin cancer surgeries often recommend nicotinamide — which is a form of Vitamin B3 — to their patients. It's been shown to protect cells from UV radiation damage.
Now, a new study of nearly 34,000 veterans, finds this over-the-counter supplement is linked to a reduction in non-melanoma skin cancers among people who've already had skin cancer. The research was published in JAMA Dermatology.
The biggest reduction was seen among people who began taking the supplement after being diagnosed with their first skin cancer. Researchers found those who took 500 mg of nicotinamide, also known as niacinamide, twice daily, for at least one month, had a 54% reduced risk of developing another skin cancer, compared to patients who did not take the supplement.
Overall, the reduction in skin cancer risk, across all the participants, was about 14 percent. The reduction was seen in non-melanoma skin cancers, including basal cell carcinoma, which is the most common, and cutaneous squamous cell carcinoma. The biggest reduction was in squamous cell cancers.
"I was very surprised at the degree of risk reduction," says study author Dr. Lee Wheless, of Vanderbilt University Medical Center and a staff physician at the Tennessee Valley Healthcare System VA Medical Center.
Evidence to support the potential benefits of B3 supplements to protect against skin cancer goes back a decade. The results of a randomized clinical trial in Australia published in 2015 that included 386 people with a history of non-melanoma skin cancers pointed to a reduced risk of new skin cancers.
The 2015 findings led many doctors to recommend B3 supplements to their patients. A survey of 1,500 doctors who perform Mohs surgery — a precise procedure to remove skin cancers — found 77% recommend nicotinamide.
Sarah Arron is a dermatologist in the San Francisco Bay area, who performs surgery on people with skin cancers. She was not involved in the study. Arron had been on the fence about when to recommend Vitamin B3 to her patients. Now, she says the new study provides stronger evidence and adds more clarity.
"The growing body of literature suggests that we should routinely recommend nicotinamide as secondary prevention for all patients with skin cancer and that earlier initiation will have a stronger effect," Arron wrote in an editorial on the study, which was published alongside the study in JAMA Dermatology.
Arron says the supplement is widely available over the counter and has "minimal adverse effects." She says people should buy the form of the supplement that ends in "amide", rather than niacin (nicotinic acid) which is another form of B3 that does not have the same effects.
"I am going to be more rigorous in recommending it to patients, especially patients who are having their first skin cancer. I think the benefit is strongest if we start it early," Arron told NPR. She says the supplement was less effective at preventing skin cancer among participants in the study who began taking B3 after they had already been diagnosed with multiple skin cancers.
She points out that more than $8 billion is spent each year to treat skin cancers in the U.S., and she says people tend to underestimate the impact of non-melanoma cancers. Squamous cell skin cancers are very treatable, and are often removed when detected early, but they can spread to other parts of the body.
One unanswered question is whether B3 supplements are beneficial for people who have never been diagnosed with skin cancer. Arron says more research is needed.
"It is certainly possible that somebody who is at higher risk for skin cancer, who's already showing signs of precancerous change in the skin, might benefit from nicotinamide," she says. "But we'll have to do those studies to see."
She says Vitamin B3 has been shown to help protect cells from UV radiation damage.
Lots of skin care products, from cleansers to serums to moisturizers include B3, which is marketed as an ingredient to help improve skin tone and texture. There may be aesthetic benefits for the skin, but Arron says it's unclear if these topical products would have any influence on cancer prevention.
This new study did not evaluate the effects of Vitamin B3 on melanoma risk, which is a type of skin cancer that has a higher risk of spreading, and can be life-threatenting when it's not identified and treated.
Arron says when it comes to prevention, the best strategy to protect skin is advice you've most likely heard: lather up with sunscreen and cover up.
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