Too little sun causes harm, cancer specialists say

Cancer specialists around the world are rethinking their advice to cover up in the sun amid growing concern that staying in the shade may be causing harm.

Cancer specialists around the world are rethinking their advice to cover up in the sun amid growing concern that staying in the shade may be causing harm.

Australia is revising its warnings about the risks of sun exposure because of fears about vitamin D deficiency, which increases the risk of a range of diseases from cancer to osteoporosis, in what doctors have described as a "revolution".

The British charity Cancer Research UK launches its annual SunSmart campaign today highlighting the dangers of too much sun. But in Australia, health experts warn that some people are getting too little. In a statement, the Cancer Council of Australia said: "A balance is required between avoiding an increase in the risk of skin cancer and achieving enough ultraviolet radiation exposure to achieve adequate vitamin D levels."

Australia is one of the sunniest countries in the world, and vitamin D deficiency is likely to be significantly worse in Britain. A survey in Geelong in Victoria, southern Australia, cited in the cancer council's statement, found that 43 per cent of women suffered a mild vitamin D deficiency and 11 per cent had moderately severe deficiency during winter. Geelong gets an average of 2,007 hours of sunshine a year, 60 per cent more than Glasgow which has 1,250 hours, according to the UK Meteorological Office.

Bruce Armstrong, professor of public health at Sydney University, said: "It is a revolution. I have worked in public health and been preaching sun avoidance for 25 years. But this statement says that there are two sides to the story."

Vitamin D is made by the action of the sun on the skin and can be stored by the body for up to 60 days. Between October and March the sun in Britain is too weak to generate vitamin D so by the end of winter most people are deficient.

A lack of vitamin D can cause rickets in children, leaving their legs deformed. Research shows it is also linked to multiple sclerosis, diabetes and cancers including those of the colon, breast, ovary and prostate. Some dermatologists are challenging the orthodox view that there is "no such thing as a safe tan" saying instead that the real risk is from sunburn, especially before the age of 20.

Neil Walker, chairman of the UK Skin Cancer Prevention Working Party, says that warnings to avoid the sun entirely are "draconian and unnecessary".

His view was supported by Professor Brian Wharton, chairman of the British Nutrition Foundation, who said: "We do need some sensible use of the sun and we have been swinging too strongly against it." Sara Hiom, head of health information at Cancer Research UK, said that concern about vitamin D deficiency was growing, and an international conference hosted by the World Health Organisation was planned.

"We do take on board the new evidence coming through. We are seriously looking at this. We need more research on who is at risk. We are not going to tell people to go out and sunbathe, but we do need to focus on those most at risk ­ with fair skin or lots of moles ­ and tell people some sunlight is good for them."