From the Associated Press:
New research linking low vitamin D levels with deaths from heart disease and other causes bolsters mounting evidence about the "sunshine" vitamin's role in good health.
Patients with the lowest blood levels of vitamin D were about two times more likely to die from any cause during the next eight years than those with the highest levels, the study found. The link with heart-related deaths was particularly strong in those with low vitamin D levels.
Experts say the results shouldn't be seen as a reason to start popping vitamin D pills or to spend hours in the sun, which is the main source for vitamin D.
For one thing, megadoses of vitamin D pills can be dangerous and skin cancer risks from too much sunshine are well-known. But also, it can't be determined from this type of study whether lack of vitamin D caused the deaths, or whether increasing vitamin D intake would make any difference.
Low vitamin D levels could reflect age, lack of physical activity and other lifestyle factors that also affect health, said American Heart Association spokeswoman Alice Lichtenstein, director of the Cardiovascular Nutrition Laboratory at Tufts University.
Still, she said the study is an important addition to an emerging area of research.
"This is something that should not be ignored," Lichtenstein said.
Scientists used to think that the only role of vitamin D was to prevent rickets and strengthen bones, Dobnig said.
"Now we are beginning to realize that there is much more into it," he said
Exactly how low vitamin D levels might contribute to heart problems and deaths from other illnesses is uncertain, although it is has been shown to help regulate the body's disease-fighting immune system, he said.
Low vitamin D levels also have been linked with several kinds of cancer and some researchers believe the vitamin could even be used to help prevent malignancies.
It has been estimated that at least 50 percent of older adults worldwide have low vitamin D levels, and the problem is also thought to affect substantial numbers of younger people. Possible reasons include decreased outdoor activities, air pollution and, as people age, a decline in the skin's ability to produce vitamin D from ultraviolet rays, the study authors said.