Britons suffering from lack of sunshine
quarter of Britons may suffer from a winter deficiency of vitamin D
and that supplementation and further fortification of foods may be
the answer.
Britain's northern location and lack of sunshine means that during the winter months many people do not get enough of the vitamin made by the body when it is exposed to sunlight.
This lack can be serious, increasing the risk of muscle weakness, autoimmune diseases, osteoporosis and certain types of cancer.
"About 25 per cent of adults are deficient in vitamin D in winter," Dr Birgit Teucher, of the Institute of Food Research, said during the briefing at the Science Media Centre.
Graham Bentham, a professor of environmental science at the University of East Anglia, said 80 per cent of vitamin D comes from exposure to sunlight, but during the months of October to March sunlight exposure in Britain is not be sufficient for the body to produce any vitamin D.
During the winter months, the body relies on stores of vitamin D built up from summer exposure to the sun and that obtained from food. However, increased time spent indoors and fears about the risks of cancer from too much sun now limit many people's exposure to sunlight, leaving them with depleted winter reserves.
The health experts concluded that more research is needed but suggested vitamin D supplements such as cod liver oil and fortifying more foods could be a solution - at present foods such as breakfast cereals and margarine are fortified with the vitamin.
The food industry could help by fortifying milk, bread and even orange juice with vitamin D.
A number of scientists have raised the profile of vitamin D deficiency in recent months, demonstrating an association with cancers, autoimmune diseases as well as fractures.
A US cancer prevention expert recently called for action to raise vitamin D levels, inciting the government to require calcium and vitamin D to be added to foods. He argued this could achieve a 20 per cent reduction in colon cancer deaths and osteoporosis-related fractures.
Most recently, a study propsed that vitamin D could be important for oral health. Researchers led by Bess Dawson-Hughes, director of the Bone Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston demonstrated that the higher the levels of vitamin D in volunteers' blood, the better their gum health. Among men and women aged 50 and older, those with the lowest vitamin D levels had 25 to 27 per cent more tooth loss than had those in the highest range.
An adequate intake for dietary vitamin D has been established as a range from 200 to 600 international units (IU) daily, depending upon age group, although recent evidence suggests that more vitamin D may be needed.
