OVERZEALOUS health campaigns warning the public to cover up to avoid skin cancer have resulted in an “unrecognised epidemic” of vitamin D deficiency, a leading researcher will warn this week.

Professor Michael Holick says that a moderate amount of unimpeded exposure to the sun on a regular basis helps the body convert ultra-violet (UV) rays into vitamin D.

He claims lack of the vitamin is causing thousands of unnecessary cancer deaths each year and increases vulnerability to rickets, a bone disease that can cripple children and makes adults more prone to weak bones and muscles.

“Dermatologists have frightened so many people about the sun that they now always wear sunblock. Even people with dark skin do not want to get sunshine to avoid skin cancer and are suffering a lack of vitamin D as a result,” said Holick, professor of medicine at Boston University in America.

“I think dermatologists have overreacted to the danger of skin cancer and I am trying to reverse that. The message is now so radical. People are being told that they should never be exposed to even one ray of direct sunlight. I think this is wrong and harmful in the long term.”

Holick, who launches the British edition of his book, The UV Advantage, tomorrow, resigned from his chair in dermatology at Boston after leading specialists condemned his views as “irresponsible”.

He advocates five to 10 minutes of unprotected sun exposure to the face, arms and hands between 10am and 3pm two to three times a week. He says people must then cover up with sunscreen, hats and clothing.

Many skin cancer experts deny there is widespread vitamin D deficiency in Britain. Sara Hiom, co-ordinator of Cancer Research UK’s SunSmart campaign, said Holick’s book could derail a health message that was struggling to be heard.

“This message is damaging. Ten minutes of sun at noon could cause people with very fair skin to burn,” said Hion.

“We are already having difficulty changing people’s behaviour by getting them to cover up. If people believe we are giving misleading messages then that is going to affect their health.”

Dr Colin Fleming, consultant dermatologist at Ninewells hospital in Dundee, said: “Today I was in the park with my children and they were the only ones wearing hats. The real risk is still overexposure to the sun.”

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