A large-scale retrospective study from the US Veterans Affairs (VA) system suggests that oral nicotinamide supplementation may reduce the risk of subsequent skin cancers, particularly when initiated after a patient’s first diagnosis.
The analysis, published in JAMA Dermatology, included data from more than 33,000 patients drawn from the VA Corporate Data Warehouse between 1999 and 2024.
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Among them, 12,287 patients received nicotinamide 500 mg twice daily for at least 30 days and were matched to 21,479 unexposed controls. The mean age of participants was approximately 77 years; 95% were White, reflecting the demographics of the VA population.
Key Findings
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Overall risk reduction: Nicotinamide was associated with a 14% reduction in skin cancer risk across the matched cohort.
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Timing matters: Patients who began nicotinamide after their first skin cancer diagnosis saw a 54% risk reduction, although this benefit diminished when supplementation started later in the disease course.
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Cancer subtype effects: Risk reduction was observed for basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), with the most pronounced benefit for cSCC.
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Transplant recipients: In solid organ transplant patients (3.9% of the cohort), no overall reduction was detected, but early initiation was linked to lower rates of cSCC.
Clinical Context
Nicotinamide, a form of vitamin B3, has been under investigation for nearly a decade as a low-cost, well-tolerated chemopreventive strategy in skin cancer. Previous smaller randomised controlled trials hinted at benefit, but large real-world evidence has been limited until now.
The findings align with earlier phase III data (the ONTRAC study), but extend the evidence base by including tens of thousands of patients in routine practice settings.
Implications for Practice
For dermatologists and oncologists, these data strengthen the case for considering nicotinamide after a first non-melanoma skin cancer. The absence of significant benefit among transplant recipients highlights the need for more targeted preventive strategies in immunosuppressed populations.
The authors conclude: “These results suggest a decreased risk of skin cancer among patients treated with nicotinamide, with the greatest effect seen when initiated after the first skin cancer.”
Paper: Breglio, K-F., et al. Nicotinamide for Skin Cancer Chemoprevention. JAMA Dermatology. doi:10.1001/jamadermatol.2025.3238 Published online September17, 2025. Access online here.
