Jul 4 2005
A British scientist suggests that some adolescents in Britain might not be getting enough sunlight to satisfy their body's requirement for vitamin D throughout the year.
He says that fear of skin cancer in the United Kingdom, may have led to children spending less time exposed to sunlight, reducing the opportunities for the production of vitamin D in the skin and resulting in poor bone health.
Some recent research has shown that sunlight exposure and the resulting synthesis of vitamin D might reduce the risk of certain cancers and, perhaps, multiple sclerosis, and in response, there have been calls for current skin cancer awareness campaigns in the UK to be abandoned.
Professor Brian Diffey, Clinical Director at Newcastle General Hospital is unsure whether such calls are justified.
It is not easy to define what is adequate sun exposure, but it is thought that a weekly dose of 1 MED (minimal erythema dose - the exposure necessary to result in a just perceptible reddening of the skin) to the face, hands and arms in the spring summer, and autumn is more than adequate to satisfy the body’s requirement for vitamin D throughout the year.
A weekly dose of about 2 MED would be required if only the face and hands are exposed.
Professor Diffey, in 1994, measured the sun exposure of 180 children and adolescents in three regions of England during the spring and summer and found that 98.5% and 91% of children and adolescents, respectively, exceeded a weekly dose of 1 MED.
However, only 58% of teenage boys, who generally exposed only their hands and face, exceeded 2 MED.
Diffey says these findings would account for the fact that the wintertime vitamin D status of almost all teenage girls living in northern Europe is insufficient.
But he also says that the evidence is not enough to justify abandoning current awareness campaigns about skin cancer, which are aimed primarily at avoiding excessive exposure.
He explains that British children and adolescents need not deliberately spend extended periods in strong sunshine, but rather, those whose lives are spent almost entirely indoors, in the shade, or in vehicles, should take the opportunity during casual everyday activities to walk on the sunny side of the street and, when possible, avoid taking the car.
The article is published in the British Medical Journal.