Broadcast: Feb 5, 2003
By Jerilyn Watson

This is the VOA Special English Health Report.

For many years, scientists have known that people need Vitamin D. The body needs the vitamin to have normal levels of the elements calcium1 and phosphorus2. Vitamin D helps the body use calcium to develop and strengthen bones and teeth. Studies show that lack of the vitamin is linked to an increased risk of broken bones. Extra Vitamin D may help prevent such breaks.

Health experts have traditionally believed that short periods of sunlight each day could provide enough Vitamin D. This is because human skin changes sunlight into Vitamin D. The body then can store this substance.

Recently, however, experts have warned that many people may not be getting enough Vitamin D. They say this is especially true of people who live in northern areas of the world. People who stay in their home, school or office for most of the day also may not be getting enough Vitamin D.

The Harvard University School of Public Health is in the northeastern city of Boston, Massachusetts. It says researchers studied patients who entered a Boston hospital. The study showed that fifty-seven percent of these patients lacked enough Vitamin D.

Some doctors now are telling patients to get at least a few minutes of sunshine every day. However, too much sunlight can cause skin cancers. So people who stay in the sun longer should use products to protect their skin.

People can also get Vitamin D in pills or food. Only a few foods naturally contain a lot of Vitamin D, however. They include fish and fish oils. The vitamin is also added to foods like milk and some cereals.

Scientists believe Vitamin D may also be important for health in other ways. The Harvard School of Public Health says research suggests a link between low vitamin D and increased risk of some cancers. These include cancer of the part of the intestine called the colon.

Vitamin D also may protect against heart disease. Last year, researchers studied almost ten-thousand older women. They were taking part in research on the bone-thinning disease, osteoporosis. Some of the women took Vitamin D pills. Others did not. The women who took the vitamin had about a thirty percent lower risk of dying of heart disease.

This VOA Special English Health Report was written by Jerilyn Watson.
1. calcium [5kAlsIEm] n. [化]钙(元素符号Ca)
2. phosphorus [5fCsfErEs] n. 磷