BLACKWHITEPAILYN/Shutterstock.comA major shift is unfolding in the field of skin cancer prevention, ignited by new research showing that an everyday vitamin supplement may prevent many cases of the world’s most frequently diagnosed cancer.The supplement in question is nicotinamide, a form of vitamin B3.Whereas previous studies hinted at a potential benefit, the latest research – spanning more than 33,000 US veterans – suggests that adding this simple vitamin pill to daily routines could dramatically lower skin cancer risk, especially for those who have already experienced their first case.The scale, breadth and clarity of this evidence are driving calls to rethink how skin cancer is prevented.Skin cancer is the world’s most common form of cancer. Non-melanoma types, including basal cell carcinoma and cutaneous squamous cell carcinoma, account for millions of new cases each year.These cancers are linked to cumulative sun exposure, fair skin and ageing. Existing prevention strategies focus on avoiding ultraviolet (UV) rays and using sunscreen, but rates continue to climb, and patients diagnosed with one skin cancer typically face a stubborn cycle of recurrence.Enter nicotinamide, a cheap, widely available supplement. Researchers observed that this form of vitamin B3 bolsters the skin’s natural repair systems after UV damage, reduces inflammation, and helps the immune system detect and clear abnormal cells.In the new study, over 12,000 patients who began taking nicotinamide at 500mg twice daily for more than a month were compared to more than 21,000 who did not. Those taking nicotinamide saw a 14% lower risk of developing any new skin cancer. The protective effect was most profound when started promptly after a first diagnosed skin cancer, resulting in a 54% drop in the risk of additional cancers.This benefit faded if supplementation started only after multiple recurrences, suggesting that timing matters. The effect was seen across both main skin cancer types but was particularly robust for squamous cell carcinoma, which can behave more aggressively and carries a greater risk of complications.It’s important to underscore that, while hopeful, these findings do not suggest nicotinamide should replace sun avoidance or routine skin checks. Wearing hats, using sunscreen and seeking shade remain pillars of prevention.Still, the simplicity, safety and low cost of nicotinamide mean that its incorporation as a daily “add-on” is an accessible step for most people, especially those with a track record of skin cancer. For dermatologists, this is an attractive profile compared to some prescription medicines used to prevent recurrence, which may be more expensive or have worse side-effects.As a secondary prevention tool, it stands out as effective and practical. The timing of intervention appears paramount, with the greatest benefit gained when nicotinamide is offered straight away. In practice, this shifts the conversation, urging healthcare professionals and patients to view the first cancer as a red flag to act decisively. Sunscreen is still one of the pillars of skin-cancer prevention. verona studio/Shutterstock.com Perspective is importantThe findings emerge from an observational study using real-world data, meaning researchers looked at health records and drew statistical associations. Most participants were white males, so the broader relevance of these findings remains uncertain.While this type of study cannot prove cause and effect as powerfully as a randomised trial, the results align with earlier, smaller trials that hinted at the same benefit. They reinforce the idea that a simple, non-pharmaceutical intervention could help in the battle against the world’s most common cancer, and at a fraction of the expense or risk of more intensive therapies.This research does not settle every question. It remains to be seen how nicotinamide performs over very long periods and whether the benefit is as robust in more diverse populations. Additionally, people who have never had skin cancer were not the focus, so broader recommendations are likely to stay reserved for those with a prior history.Still, for those confronting the anxiety of a first skin cancer diagnosis, the promise of a readily available, low-cost and well-tolerated supplement offers a new sense of control.Justin Stebbing does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.