Can a vitamin you can buy at the chemist really help reduce your risk of skin cancer?
For some people, the answer may be yes.

If you’ve had skin cancer before — or you’ve been told you have significant sun damage — it can feel like you’re always waiting for the next lesion to appear.

In this blog, I’ll explain what niacinamide (vitamin B3) is, how it works in sun-damaged skin, what the research actually shows, and who it may be useful for.

What Are We Trying to Prevent?

When we talk about preventing skin cancer, we’re usually talking about two related problems.

Actinic keratoses (AKs)

These are rough, scaly patches that appear on sun-exposed areas like the face, scalp, ears, arms, and hands.
They aren’t cancer, but they can progress to squamous cell carcinoma over time.

Non-melanoma skin cancer

This includes:

• Basal cell carcinoma (BCC)

• Squamous cell carcinoma (SCC)

These cancers are caused primarily by long-term ultraviolet (UV) exposure and are extremely common in fair-skinned people.

Most patients I see with these issues are over 50 and have spent decades outdoors — farming, building, gardening, golfing, or travelling. The damage accumulates slowly, and often the first warning sign is a persistent crusty spot or a biopsy report containing the word carcinoma.

So the question becomes:
Can we reduce the number of new lesions before they appear?

Conventional Treatments: Effective, But Reactive

Once sun damage is established, most treatments focus on what’s already visible.

• Cryotherapy (freezing) is quick but painful, especially when there are many lesions

• Topical treatments like fluorouracil or imiquimod can cause significant redness, crusting, and discomfort

• Photodynamic therapy can be effective but isn’t always accessible

• Surgery remains the gold standard for established skin cancers

• In very high-risk cases, oral retinoids may be used, but they require close monitoring and can have side effects

All of these approaches are important — but they’re reactive.

Which brings us to niacinamide.

Niacinamide: A Preventive Approach

Niacinamide (also called nicotinamide) is a form of vitamin B3.
It’s available over the counter and is not the same as niacin (nicotinic acid).

That distinction matters:

• Niacin can cause flushing — a warm, red sensation in the skin

• Niacinamide does not cause flushing and is the form used in skin cancer research

So how does it work?

Niacinamide helps skin cells in several important ways:

• Supports DNA repair after UV exposure
  It’s a key building block for enzymes that repair UV-induced DNA damage.

• Maintains cellular energy (NAD levels)
  This gives damaged skin cells the fuel they need to recover and function properly.

• Supports local immune defence in the skin
  UV light suppresses immune surveillance. Niacinamide helps counteract this effect.

• Reduces inflammation
  Lower inflammation creates a healthier environment for skin cells to recover.

Some people also notice improvements in skin texture or redness, but the primary focus here is cancer prevention, not cosmetics.

Put simply:
niacinamide helps sun-damaged skin behave more like healthy skin again.

What Does the Evidence Show?

This isn’t theoretical — it’s been tested in large, real-world studies.

The ONTRAC Trial (2015)

A landmark Australian study published in The New England Journal of Medicine followed people with a history of skin cancer.

Participants took either:

• Niacinamide 500 mg twice daily, or

• A placebo

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After 12 months, the niacinamide group had:

• 23% fewer new non-melanoma skin cancers

• Fewer actinic keratoses

For a vitamin, that’s a meaningful effect.

The VA Cohort Study (2025)

A more recent study looked at over 33,000 US veterans, mostly older, fair-skinned men.

The same dose — 500 mg twice daily — was associated with:

• 14% fewer skin cancers overall

• 22% fewer squamous cell carcinomas

Most interestingly, people who started niacinamide after their first-ever skin cancer saw the largest benefit — around a 50% reduction.

Timing matters.

When Is the Best Time to Start?

Niacinamide works best early.

The ideal time to consider it is:

• After a first confirmed BCC or SCC, or

• When multiple actinic keratoses begin to appear

If someone has already had many skin cancers over many years, the benefit is smaller — because niacinamide helps prevent new damage, not reverse decades of existing genetic injury.

If you’re fair-skinned and your GP has mentioned “significant sun damage,” it’s worth discussing.

What Niacinamide Is Not

It’s important to be clear:

• It is not a cure for existing skin cancer

• It won’t make lesions disappear overnight

• It does not replace sunscreen or regular skin checks

Think of it like a seatbelt.
It doesn’t prevent the crash — but it can significantly reduce the harm.

Dose, Safety, and Who It’s For

• Recommended dose: 500 mg twice daily

• Available without prescription

• Generally well tolerated

That said, you should always discuss it with your GP before starting, particularly if you have kidney issues or take other medications.

This is not something we routinely recommend to younger people with minimal sun damage. It’s a targeted strategy for higher-risk individuals — typically fair-skinned adults over 50 with a history of sun damage or skin cancer.

A Small Step That Restores Agency

If you’ve lived through repeated freezing treatments, surgeries, or inflamed topical therapies, you’ll know how draining it can feel.

Niacinamide isn’t a miracle.
But it is a small, evidence-based step that can help shift things in your favour.

If it’s appropriate for you, it may help prevent the next lesion — before it ever appears.

Learn More

If you’d like to go deeper, I’ve linked related videos below, including a detailed explanation of actinic keratoses and how we decide when to treat them.

References

• Chen AC et al. NEJM, 2015 — ONTRAC Trial

• Breglio KF et al. JAMA Dermatology, 2025 — VA Cohort Study