How to reduce your skin cancer risk

Skin cancer is one of the most preventable cancers, because its biggest driver — ultraviolet radiation — is something we can act on. This guide covers the foundations that apply to everyone, and then the additional, evidence-based steps we use for people at higher risk, including those who have already had a skin cancer.

If you have had a skin cancer before, the goal shifts from detection alone to active secondary prevention — repairing the underlying sun damage and lowering the chance of the next lesion forming. Having had one non-melanoma skin cancer substantially raises the risk of another, and that risk is highest in the first few years. ⁽⁹⁾

1. Sun protection — the foundation

The single most important strategy, for everyone, is reducing new UV exposure. Past damage cannot be undone, but preventing further damage prevents new cancers. The practical rules are built around the UV Index: whenever it reaches 3 or above, use a combination of measures rather than relying on any one. ⁽²⁾

• Mind the midday gap. UV is strongest roughly 10am–4pm in the warmer months — minimising exposure then is the most effective way to cut your cumulative UV load.
• Cover up. Loose UPF 50+ clothing, a broad-brim hat and sunglasses are physical barriers that do not wash off or get forgotten — far more reliable than sunscreen alone for the back, arms and torso. See sun protection beyond sunscreen →.
• Seek shade. Good shade markedly reduces UV, though scattered and reflected UV still reach you.
• Use sunscreen on the rest. Apply broad-spectrum SPF 50/50+ to exposed skin and reapply every two hours outdoors. Regular sunscreen use is not just theory — in a randomised trial, regular sunscreen users developed fewer melanomas than the discretionary-use group. ⁽¹⁾ See our sunscreen guide →.
• Never use tanning beds. Sunbed use increases melanoma risk — most of all when first use is before age 35 — and UV-emitting solariums are classed as carcinogenic to humans. ⁽³⁾

For the high-risk patient especially, sun protection is a medical necessity: new UV on top of old damage is the spark that ignites new cancers.

2. Vitamin B3 (nicotinamide)

Nicotinamide gives skin cells an energy boost (via NAD⁺) that supports repair of UV-induced DNA damage and reduces UV-driven immune suppression — helping correct damage before it can become cancer.

• The evidence: in the randomised ONTRAC trial, 500 mg twice daily reduced new non-melanoma skin cancers by 23% in high-risk patients. ⁽⁴⁾ A large 2025 cohort study (nearly 34,000 patients) found the benefit was greatest — about a 54% reduction — when nicotinamide was started after the first skin cancer, and smaller when started later. ⁽⁵⁾
• The method: 500 mg twice daily, long term. Use nicotinamide / niacinamide, not niacin (nicotinic acid), which causes flushing.

Vitamin B3 also helps applied to the skin — a niacinamide serum (around 10%) has photoprotective effects and can reduce actinic keratoses over time ⁽⁶⁾ — and it occurs naturally in food, though diet alone cannot reach the ~1,000 mg/day used for prevention. ⁽⁷⁾

For the full protocol — dosing, brands (and how many tablets a day), the topical serum, dietary B3, statin and safety notes, and the transplant caveat — see the vitamin B3 (nicotinamide) guide →.

3. Field therapy — treating the “soil”

Removing a single skin cancer is like pulling one weed; field therapy treats the whole sun-damaged area (the “soil”) to clear invisible, sub-clinical damage. Using prescription creams or laser-assisted photodynamic therapy, we “reset” an at-risk area to lower the chance of the next cancer forming — see treating sun damage with field therapy → and actinic keratosis treatment →.

4. The HPV vaccine (Gardasil 9, off-label)

For patients with a high actinic-keratosis burden — frequently having pre-cancers frozen or treated — there is emerging interest in the HPV vaccine. The 2025 VAXAK randomised trial found the 9-valent HPV vaccine reduced actinic keratosis counts more than placebo in immunocompetent patients. ⁽⁸⁾ It is off-label, not standard care, and supplementary to the steps above — see Gardasil 9 for AK prevention →.

5. Precision surveillance

After a skin cancer, the “wait and see” approach is replaced by a structured surveillance plan, because the risk of a further skin cancer is real and concentrated in the first few years. ⁽⁹⁾ Regular professional checks catch new lesions and field changes early, when treatment is simplest — see life after a skin cancer diagnosis → and our skin check hub →.

6. Vitamin D — the nuanced picture

People rightly worry that strict sun protection could affect vitamin D. You do not need deliberate sun exposure to maintain it: get vitamin D from diet and a supplement (oily fish, eggs and fortified foods; a common maintenance dose is 1,000–2,000 IU/day, with your doctor advising if you are deficient). ⁽²⁾

The relationship between vitamin D and skin cancer is genuinely nuanced. Low vitamin D at the time of a melanoma diagnosis is associated with thicker tumours and, in some studies, poorer survival. ⁽¹²⁾ And there is real biological plausibility that vitamin D could help: acting through the vitamin D receptor, it can slow cell proliferation, encourage normal cell maturation, dampen inflammation, quieten cancer-promoting growth signals (such as the Wnt/β-catenin pathway) and support repair of UV-damaged DNA — and mice lacking the vitamin D receptor develop more UV-induced skin tumours.

Despite that promise, the research on actually taking vitamin D has generally been disappointing. Randomised trials of vitamin D supplements have not reduced skin cancer, and a randomised melanoma trial found no improvement in relapse or survival despite successfully raising vitamin D levels. ⁽¹³⁾ The likeliest explanation for the favourable associations is confounding — sunlight raises both vitamin D and skin cancer risk, so a high vitamin D level often just marks more sun exposure or better general health.

The practical takeaway: correct a genuine deficiency for your overall health (your doctor may check your level around a melanoma diagnosis), but do not chase high vitamin D levels as a skin cancer strategy, and never use the sun as your vitamin D source. For the full evidence explained simply, see vitamin D and skin cancer — what the evidence shows → and nutrition and vitamin D for sun-avoidant patients →.

7. Special considerations for high-risk groups

Some patients need more intensive, individualised protocols:

• Organ transplant recipients — a markedly higher risk of aggressive squamous cell carcinoma. ⁽¹⁰⁾
• Immunosuppressed patients — reduced immune surveillance of the skin.
• Outdoor workers — occupational UV is an established risk factor that roughly doubles squamous cell carcinoma risk. ⁽¹¹⁾

For these groups, physical protection and structured surveillance matter even more — see advanced protection for high-risk groups →.

Book a skin check

A professional skin check is the cornerstone of prevention — for early detection and for building the right ongoing plan for you.