Updated
A simple oral dose of an active form of vitamin B3 may be the secret to stopping people with significant sun damage from developing some forms of skin cancer.
New research from the University of Sydney has found that a high dose of vitamin B derivative nicotinamide can prevent up to a quarter of non-melanoma skin cancers.
Nicotinamide is an active form of vitamin B3 that is commonly found in meat, fish, nuts and mushrooms, as well as some vegetables.
Scientists and dermatologists have long suspected that it plays a significant role in helping prevent some types of skin cancer.
The study, funded by the National Health and Medical Research Council of Australia, has gone a long way towards proving that.
Dr Andrew Martin and a team of researchers enlisted a group of more than 380 volunteers who had all had two or more non-melanoma skin cancers over the past five years.
Half were given a high oral dose of nicotinamide, while the other half were fed a placebo.
"They remained on treatment for 12 months and had regular dermatological checks over that time period, and at the end we found that people that had been allocated to nicotinamide had about a quarter fewer skin cancers than those that had be allocated placebo," said Dr Martin.
Dermatologist Dr Michael Freeman from the Gold Coast University Hospital is one of many medical professionals who have been using nicotinamide with their patients for years.
"(Since) the first trials came out showing us that the nicotinamide prevented the immunosuppression caused by the sun, I've been giving all of my patients who are sun damaged nicotinamide," he said.
"And provided that they are not allergic to it, they've found in general a good 30 per cent improvement in their skin damage, so that they have to have 30 per cent less treatments given to them over time."
Not all forms of vitamin B work for sun damage
He described the study as definitive proof that nicotinamide can help with skin cancer.
"It is extraordinary that something simple that has been out there for, well 30 years dermatologists have been using it for various skin conditions, but this is the first time that we've actually understood how well it works for sun damage.
"I should add that nicotinamide, although it is a B3 vitamin, is the active form of B3, so taking the inactive form of the B3 will not give you the same effect, in fact it will give you terrible side effects of flushing usually."
Dr Martin was also keen to stress that simply taking high doses of vitamin B would be ineffective or even dangerous.
"There are different types of vitamin B.
"Nicotinamide is the amide form of the vitamin and that's an important point to make, there are other forms, like niacin or nicotinic acid that have actually got known side effects associated with them.
"So our study specifically tested nicotinamide and in doses that far exceed what would be normally be taken in as part of a standard diet.
Both doctors say that by far the best way to prevent skin cancer is to protect skin from sun damage in the first place.
The study has been published today in the New England Journal of Medicine.