How a vitamin in beer and Vegemite could prevent our most common cancer

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Diarrhoea, dermatitis, dementia, and death. These are the “four Ds” of pellagra, a condition caused by a deficiency in vitamin B3.

Happily, the vitamin is readily available from a range of delicious sources including chicken, tuna, eggs, milk, peanuts, cereals and yeast. You can also get it from the distinctly Aussie sources of Vegemite and beer.

But aside from avoiding the dreaded four Ds, increasingly convincing research shows that a simple form of vitamin B, nicotinamide – a widely available supplement – might also slash rates of Australia’s most common cancer.

Scientists have found the cheap, safe substance may significantly reduce risk of non-melanoma skin cancers, which represent 99 per cent of skin cancer cases.

A new study of 33,000 people found taking nicotinamide was associated with a 20 per cent reduction in the risk of squamous cell carcinoma, which is responsible for the highest number of deaths among non-melanoma skin cancers.

In a world where vitamins rarely live up to the hype of their health claims, how did we get to a stage where experts look favourably on nicotinamide as a “practical tool for skin cancer prevention”, as one scientist puts it? A building body of international evidence has its roots in Sydney.

The early clues

UV radiation causes skin cancers by damaging DNA and suppressing the skin’s immune system, so the body finds it harder to repair that damage.

Much of the early evidence that hinted nicotinamide could protect against this effect was unearthed by Professor Diona Damian from the University of Sydney.

In 2009, Damian and her colleagues published the results of an experiment where they beamed participants’ lower backs with UV radiation to mimic natural sunlight.

When the participants took nicotinamide, they were more resistant to the immunosuppression caused by UV. That was one of the early experiments that hinted the supplement might help curb the development of skin cancers.

UV blocks the energy-hungry process of DNA repair by depleting a molecule called NAD+, which mitochondria need to produce ATP, the body’s cellular energy source. Nicotinamide is a precursor to NAD+.

As Damian put it in 2008: “Our research found that nicotinamide (vitamin B3) can prevent the immunosuppressive effects of UV by energising cells so they maintain their immunity.”

An influential Sydney study

In 2015, Damian published a phase 3 double-blind randomised controlled trial (the gold-standard, in scientific speak) known as the ONTRAC study, which ran at the Royal Prince Alfred and Westmead Hospitals in Sydney.

The trial involved 386 participants who had developed at least two non-melanoma skin cancers in the past. Skin cancer is more likely to occur in people who have had it before.

Over a year, participants took 500mg of nicotinamide twice a day or a placebo. The results were compelling: the rate of new skin cancers was 23 per cent lower in the group taking nicotinamide compared to the controls.

The results of the ONTRAC trial, however, were criticised in a follow-up 2017 statistical analysis that concluded there was insufficient evidence from that trial to confidently support nicotinamide’s efficacy. The analysis claimed the vitamin’s effect on bringing down skin cancer rates was probably more like 5 per cent.

But more evidence recently landed that supports the idea that this humble little pill could make a big difference in skin cancer rates.

The latest research

US scientists analysed the health records of 33,000 veterans in a new study published in September. About 12,000 of the veterans had, at some stage between 1999 and 2024, regularly taken nicotinamide. The scientists reported a 14 per cent reduction in skin cancer risk for that group compared to those who had never taken the supplement.

“The greatest impact was seen in squamous cell carcinoma, where risk dropped by more than 20 per cent,” Dr Yousuf Mohammed, a senior research fellow at the University of Queensland’s Frazer Institute, said when the results came out. Mohammed wasn’t involved in the study.

“Even more striking, patients who began nicotinamide after their very first skin cancer had risk reductions of nearly 50 per cent,” he said, adding nicotinamide is “showing real promise as a practical tool for skin cancer prevention”.

Almost 95 per cent of the study’s participants were white men, so more research is needed to test if the suggested benefit could extend to other ethnic groups. As an observational study, it also can’t prove direct causation, although the large sample size boosts its statistical power.

Nicotinamide also didn’t seem to help organ transplant recipients, who are 65 times more likely to develop skin cancer due to immunosuppressant drugs.

So far, we only have good evidence for nicotinamide’s effect on non-melanoma cancer. Research investigating whether it could protect against melanoma – the deadlier but much rarer kind of skin cancer – is still developing.

What’s the takeaway?

Two in every three Australians will get a skin cancer at some point, and there’s a 99 per cent chance it will be a non-melanoma cancer.

Based on the available evidence, many experts have concluded it’s reasonable to recommend nicotinamide for people at higher risk of skin cancer.

Taking nicotinamide does not make you less likely to get sunburnt, and it can’t replace using sunscreen, covering up or seeking shade to protect your skin. It’s not known whether dietary B3 has the same effect as a nicotinamide supplement, and you should talk to your doctor if considering taking a new vitamin.

Off the back of the study of veterans, US dermatologist Dr Sarah Arron said she would be recommending nicotinamide more enthusiastically to her patients.

“The medication is widely available and has minimal adverse effects, so long as patients are properly counselled to buy the amide form rather than niacin (nicotinic acid),” Arron wrote in JAMA Dermatology.

“The growing body of literature suggests that we should routinely recommend nicotinamide as secondary prevention for all patients with skin cancer and that earlier initiation will have a stronger effect.”

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