A daily vitamin pill could help prevent skin cancer - particularly among women, it has emerged.

Scientists say taking food supplements containing vitamin A can make people less likely to develop melanoma, the deadliest form of the disease.

A study found that retinol - a key component of Vitamin A - could protect against the illness.

The strongest protective effects were found in women and in sun exposed sites, suggesting retinol actually combats skin cancer.

However, there was no association between dietary intake of vitamin A, found in liver, eggs and milk, and a reduction in risk.

There was also no reduced risk seen by the intake of carotenoids, which are abundant in vegetables including carrots and tomatoes and soak up compounds that can damage the skin.

Previous research with mice has shown retinol and carotenoids can shrink melanoma tumours and improve survival.

So dermatologist Dr Maryam Asgari and colleagues analysed the disease risk in 69,635 men and women aged between 50 and 76 who consumed vitamin A through either dietary or supplementary methods.

Their findings, published in the Journal of Investigative Dermatology, found those who used retinol regularly were 60 per cent less likely to develop skin cancer, rising to 74 per cent among participants on the highest doses of more than 1,200 mg a day.

Dr Asgari, of the Kaiser Permanente Northern California Division of Research in Oakland, said: 'Our data suggest a possible interaction between supplemental retinol use and the anatomic site of melanoma, with sun-exposed sites showing a stronger protective effect than sun-protected sites.

'It may be that retinol's effects may be mediated by sunlight exposure. This intriguing possibility warrants further exploration in future studies.'

Retinol belongs to a class of compounds called retinoids that have been shown to stop cells dividing and spreading.

Dr Asgari said: 'In summary, our data, which are based on a large prospective cohort, suggest retinol intake from individual supplements is associated with a reduction in risk for melanoma, especially among women.

'Our findings suggest vitamin A supplementation may hold promise as a chemopreventive agent for melanoma.'

Skin cancer is the most common type of cancer among white populations, in the UK and worldwide.

Most are easy to treat and pose only a small threat to life, but melanoma is difficult to treat unless detected early.

Over the past 25 years, rates of melanoma in the UK have risen faster than any other common cancer.

About 1,800 people die from melanoma annually in the UK. Even so, nearly 80 per cent of men and over 90 per cent of women are alive at five years following treatment.

However, Dr Claire Knight, senior health information officer at Cancer Research UK, said: 'We don't recommend people start taking retinol supplements based on this study, particularly as high doses can be toxic.

'The result was based on a very small number of people with melanoma, and the authors didn't account for other important factors that influence the risk of skin cancer, such as the number of moles a person has.

"And crucially, when the authors looked at whether a particular dose was linked to risk, the link between retinol and melanoma disappeared.'