Lack of Vitamin D Boosts Death Risk
MONDAY Aug. 11, 2008 -- Inadequate vitamin D could increase your risk of death by 26 percent, a new study concludes.
Yet many people are not getting enough vitamin D, which the skin makes naturally when exposed to sunlight. A nationwide survey found that 41 percent of men and 53 percent of women in the United States were not getting enough of this vital nutrient.
"The importance of vitamin D may be underappreciated," said lead author Dr. Michal Melamed, a clinical fellow at Johns Hopkins University. "There are studies that link low vitamin D levels to the development of heart disease, peripheral arterial disease, diabetes, hypertension and different cancers," she said.
The report was published in the Aug. 11 online edition of the Archives of Internal Medicine.
For the study, Melamed's team collected data on more than 13,000 men and women who took part in the Third National Health and Nutrition Examination Survey. Levels of vitamin D were collected in 1988 and 1994, and the participants were followed through 2000.
During more than eight and a half years of follow-up, 1,806 people died. Among these, 777 died from cardiovascular disease. Four hundred of these people were found to be deficient in their vitamin D levels.
"Those who had the lowest levels of vitamin D had a 26 percent higher risk of death from all causes compared to those with the highest vitamin D levels," Melamed noted.
The findings in this study confirm a trend seen in other studies linking vitamin D deficiency to increased risk for breast cancer and depression in the elderly, the researchers noted. Melamed's group had previously shown that vitamin D deficiency increases the risk of peripheral artery disease (circulatory problems in the legs) by 80 percent.
Among other things, vitamin D is essential for maintaining levels of calcium and phosphorus in the body. "Vitamin D may be very important for overall health," Melamed said.
According to the U.S. Institute of Medicine, people should get between 200 and 400 international units of vitamin D a day. The best way to get vitamin D, naturally, is by being out in the sun.
As little as 10 to 15 minutes of sun a day can give you all a vitamin D you need. Vitamin D is also available in small quantities in foods such as fish and milk.
Whether vitamin D supplements are effective isn't yet known, Melamed said. "That's the million-dollar question," she said.
"I think people should optimize their diet and sun exposure to get an adequate level of vitamin D without taking supplements," Melamed said. "It may be a good idea for people who are at risk for vitamin D deficiency, including African Americans and people who don't spend a lot of time in the sun, to get their vitamin D levels checked by their doctor."
Dr. Michael F. Holick, director of the Vitamin D, Skin and Bone Research Laboratory at Boston University Medical Center, advocates high levels of vitamin D supplements to maintain good health. Vitamin D deficiency is probably the most common medical problem worldwide, Holick said.
"We know that being vitamin D sufficient reduces the risk of having your first heart attack by more than 50 percent, reduces the risk of having peripheral vascular disease by as much is 80 percent and decreases the risk of prostate, colon, breast and a whole host of other cancers by as much is 50 to 70 percent," Holick said.
In addition, not getting enough vitamin D also increases your risk for type 2 diabetes, Holick noted. By increasing your vitamin D intake to 800 international units a day reduces the risk of developing diabetes by as much as a third, he said.
Holick recommends taking high doses of vitamin D supplements, as well as sun exposure. In addition, Holick recommends taking as much as 1,400 international units of a vitamin D supplement every day.
For more about vitamin D, visit the U.S. National Institutes of Health.
Posted: August 2008