If you wear sunscreen, stay in the shade, and still worry about skin cancer, you’re not alone. About one in five Americans will face skin cancer at some point, which makes any safe prevention option worth a closer look. A new study suggests that vitamin B3, a common and inexpensive supplement, could help cut that risk in a meaningful way.
What the Study Found
Researchers at Vanderbilt University Medical Center analyzed medical records from more than 33,000 U.S. veterans. Out of this group, over 12,000 took vitamin B3 (in the form of nicotinamide) twice daily, while the rest did not. When the researchers compared outcomes, those who used vitamin B3 had a 14% lower risk of developing any type of skin cancer. The biggest impact was seen in squamous cell carcinoma, one of the more common and potentially aggressive skin cancers, where the risk dropped by more than 20%.
Who Benefits Most
The protective effect wasn’t equal across all groups. People who had already experienced a single skin cancer saw the clearest gains, with their risk of developing another dropping by about 50%. That’s a major reduction for a group that’s already more vulnerable.
For individuals with multiple past skin cancers, however, the benefit was smaller. Dermatologists note that years of accumulated sun damage may create many “hot spots” for cancer growth, making it harder for one intervention to make a big difference. The study also looked at transplant recipients, a group at especially high risk due to immune-suppressing medications, and found no overall reduction in risk for them as a whole. Still, researchers believe that early use of vitamin B3 in this population could be worth further study.
How Vitamin B3 Works
Skin cancer develops when DNA in skin cells becomes damaged, often from years of UV exposure, and those damaged cells multiply unchecked. Vitamin B3 appears to help by boosting the skin’s natural ability to repair DNA and by supporting healthy immune responses in the skin.
In simpler terms: it helps skin cells “bounce back” after sun exposure, repairing damage before it can accumulate. This doesn’t mean it erases decades of damage, but it may slow the progression of new cancers in healthier or less-damaged areas. The fact that improvements were seen in as little as 30 days suggests the body can respond quickly when given the right tools. It’s important to understand what type of vitamin B3 we’re talking about. Nicotinamide, the form studied here, is different from niacin, another type of B3 that can cause flushing and other side effects. Nicotinamide is generally well tolerated and available over the counter at a low cost.
In this study, the common dose was 500 mg twice daily. That can serve as a useful starting point for conversations with a dermatologist or primary care provider. But experts stress that vitamin B3 should not replace core sun safety habits like sunscreen, protective clothing, and avoiding peak sun hours. Instead, it may be a helpful add-on, especially for those at higher risk.
What the Study Doesn’t Prove
Because this was an observational study using medical records, it can’t definitively prove that vitamin B3 caused the reduction in cancer risk. People who take supplements may also practice healthier habits in general, such as avoiding the sun or attending more regular check-ups.
The study population—U.S. veterans—also has unique characteristics, including higher rates of sun exposure, older age, and more health conditions compared to the general public. That means results may not apply equally to everyone. The best length of time to use vitamin B3 is also still unclear, since people who took it longer were often those with more extensive disease.
Why This Matters for Patients and Doctors
For patients, especially those who have already had a skin cancer, this research adds a simple, accessible tool to the prevention toolkit. Dermatologists may now be more likely to recommend vitamin B3 to patients at elevated risk, particularly those early in their skin cancer journey. For clinicians, the findings highlight the importance of tailoring prevention strategies. A one-size-fits-all approach doesn’t work for skin cancer prevention, but combining lifestyle measures with targeted supplementation could improve outcomes.
The next step is confirming these results in prospective clinical trials that follow patients over time. Researchers also want to better understand how vitamin B3 works across different skin types, levels of sun damage, and health conditions. Special attention will likely focus on transplant recipients and people with very high cumulative sun exposure, since the benefits were less clear in these groups. Scientists also want to determine how long patients should continue supplementation and whether benefits grow—or plateau—over years of use.
The Big Picture
Vitamin B3 in the form of nicotinamide is a safe, affordable, and widely available supplement that may help lower the risk of skin cancer. The biggest benefits appear for people who have already had one skin cancer, especially squamous cell carcinoma, though even those without a history may see modest protection.
Pairing vitamin B3 with sunscreen, protective clothing, and regular skin checks offers a well-rounded defense strategy. If you’re concerned about your risk, it’s worth asking your dermatologist whether vitamin B3 is right for you. Small steps like this could add up to a big difference in skin health over time.
