The participants were 33,822 U.S. veterans (average age of 77; 98% men, 2% women ). The researchers reviewed the participants’ medical records from the last 25 years to look for any associations between nicotinamide prescriptions and nonmelanoma skin cancer.

The participants had all been diagnosed with skin cancer (median of 3 diagnoses). The types of skin cancer were basal cell carcinoma and squamous cell carcinoma (but not melanoma).

Of these participants, 12,287 had been prescribed nicotinamide to reduce skin cancer recurrence. The dose was 500 mg twice per day for more than 30 days.

The participants who were prescribed nicotinamide had a 14% lower risk of skin cancer recurrence.

Lower rates of nonmelanoma skin cancer with nicotinamide supplementation

In general, earlier nicotinamide supplementation was associated with larger reductions in skin cancer recurrence. For example, when taken after only 1 previous skin cancer diagnosis, nicotinamide was associated with a 56% lower risk of skin cancer recurrence.

Risk reductions with nicotinamide were more consistent with squamous cell carcinomas than for basal cell carcinomas.

Only 4% of participants were organ transplant recipients, which is a population at high risk of skin cancer. In this subgroup, nicotinamide was associated with a 53% lower risk of skin cancer if prescribed early, after 1 or 2 skin cancer diagnoses.

Lower rates of skin cancer recurrence with nicotinamade Original paper