Those at risk of skin cancer are routinely advised to slather on sunscreen and stay out of the sun. Gaining popularity as an additional safeguard is nicotinamide, a form of vitamin B3. It has been flying off pharmacy shelves since 2015, when the New England Journal of Medicine published a University of Sydney study that found nicotinamide significantly lowered the risk of common, non-melanoma skin cancer in high-risk patients.
“This is the first clear evidence that we can reduce skin cancers using a simple vitamin, together with sensible sun protection,” said the study’s senior author, Dr. Diona Damian, a professor of dermatology at the University of Sydney and Royal Prince Alfred Hospital, in a press release. “However, people at high risk of skin cancer still need to practice sun safe behavior, use sunscreens and have regular check-ups with their doctor.”
All 386 participants in the Sydney study had a history of skin cancer, increasing their risk for additional skin cancers. Taken as a twice-daily pill for 12 months, nicotinamide reduced the incidence of new non-melanoma skin cancers by 23 per cent relative to placebo controls and cut the incidence of pre-cancerous sun spots by around 15 per cent.
While nutritional supplements are often dismissed as unnecessary or even potentially harmful, researchers have generally recognized the potential benefits of nicotinamide.
“Nicotinamide has been show in a clinical trial — called ONTRAC — to reduce the incidence of non-melanoma skin cancer in high-risk individuals and it would be worthwhile to determine whether it would also be useful for high-risk melanoma patients,” said Dr. Gary Halliday, senior author of the Photodermatology, Photoimmunology & Photomedicine review in a 2017 report.
Nicotinamide is affordable — a bottle of 60 capsules selling for as little as $11.49 online — safe when used as directed, and available over the counter in most countries.
The primary cause of non-melanoma skin cancer is sun exposure. Despite intensive sun protection campaigns, the incidence of skin cancer continues to increase worldwide. More than 5.4 million cases of nonmelanoma skin cancer were treated in over 3.3 million people in the U.S. in 2012, the most recent year new statistics were available, according to the Skin Cancer Foundation. More people are diagnosed with skin cancer each year in the U.S. than all other cancers combined.
The most common types of non-melanoma skin cancer are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). SCCs can metastasize or spread to lymph nodes and internal organs. BCCs rarely spread but can cause huge cosmetic problems as they often occur on the face. Nicotinamide had comparable efficacy in preventing BCCs and SCCs.
In this Univerity of Sydney study, 386 patients (average age 66 years) who had at least two non-melanoma skin cancers in the last five years – and were therefore considered to be at high risk – were randomly assigned to daily nicotinamide or placebo for 12 months. The study population reflected the mix of patients typically seen in a skin cancer clinic.
The rate of new non-melanoma skin cancer was 23 per cent lower in the nicotinamide group compared to the placebo group. The average number of actinic keratoses (pre-cancerous sun spots) in the nicotinamide group was consistently lower during treatment, ranging from an 11 per cent reduction at three months, to a 20 per cent at nine months.
The study was not designed to test whether nicotinamide would benefit people in the general population who have not had skin cancer, or whether it could be effective in reducing melanoma. Whilst the researchers hope to investigate these questions in the future, there is currently no evidence that nicotinamide should be used in these settings.
This study builds on a decade of evidence from preclinical and early clinical studies, which suggests nicotinamide enhances the repair of DNA in skin cells damaged by sunlight. Nicotinamide also appears to protect the skin’s immune system from UV radiation by providing skin cells an extra energy boost when they are in repair-mode after sun exposure.