One of Britain's most outstanding scientists says the growth in use of electronic tablets and smartphones is causing people to spend at least one hour less outdoors each day, so that they need to take regular vitamin D supplements(补充) to make up for the lack of sunlight they receive naturally.
Speaking at the Hay Literary Festival in Wales, geneticist Steve Jones said he himself was a follower to the cause and urged others to follow. "I never thought I would be a person who would take vitamin supplements, I always thought it was absolute nonsense. But now I take vitamin D every day. Today, because I knew the sun wasn't going to shine, I took an extra one," he said.
Exposure to UV light from the sun is the major source of vitamin D. However, people are spending less and less time outdoors in many areas. The problem is particularly serious in Scotland. "The Scots are the palest people in the world…for their entire body systems are crying out for vitamin D," he said, adding that life expectancy in Scotland is two years shorter than in England or Wales. Multiple sclerosis(多发性硬化症), a medical condition which is often seen in northern Europe, is also higher in Scotland than in England.
Vitamin D helps with the absorption of Ca, which helps keep bones strong, and he said the fact that rickets, a bone disease, was making a comeback in Britain after nearly 50 years was another sign of how changing behavior patterns were bringing physical harm.
Jones admitted that concerns over the damaging effects on skin of long-time exposure to the sun were reasonable, but said sunlight was healthy and necessary for the human body, and could help in lowering blood pressure. "If you lie on the beach for an hour, you will drop your blood pressure by about 10 points, because it relaxes your blood vessels(血管). So, get out in the sun while we still can." He said.
