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Sun, 04/06/2014 - 14:44
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Low vitamin D levels linked to disease in two big studies

Tehran, April 6, IRNA - People with low vitamin D levels are more likely to die from cancer and heart disease and to suffer from other illnesses, scientists reported in two large studies published recently in New York Times. The new research suggests strongly that blood levels of vitamin D are a good barometer of overall health. But it does not resolve the question of whether low levels are a cause of disease or simply an indicator of behaviors that contribute to poor health, like a sedentary lifestyle, smoking and a diet heavy in processed and unhealthful foods. Nicknamed the sunshine nutrient, vitamin D is produced in the body when the skin is exposed to sunlight. It can be obtained from a small assortment of foods, including fish, eggs, fortified dairy products and organ meats. And blood levels of it can be lowered by smoking, obesity and inflammation. Vitamin D helps the body absorb calcium and is an important part of the immune system. Receptors for the vitamin and related enzymes are found throughout cells and tissues of the body, suggesting it may be vital to many physiological functions, said Dr. Oscar H. Franco, a professor of preventive medicine at Erasmus Medical Center in the Netherlands and an author of one of the new studies, which appeared in the journal BMJ. When the researchers looked at supplement use, they found no benefit to taking one form of the vitamin, D2. But middle-aged and older adults who took another form, vitamin D3 — which is the type found in fish and dairy products and produced in response to sunlight — had an 11 percent reduction in mortality from all causes, compared to adults who did not. In the United States and Europe, it is estimated that more than two-thirds of the population is deficient in vitamin D. In their paper, Dr. Franco and his colleagues calculated that roughly 13 percent of all deaths in the United States, and 9 percent in Europe, could be attributed to low vitamin D levels. “We are talking about a large part of the population being affected by this,” he said. “Vitamin D could be a good route to prevent mortality from cardiovascular disease and other causes of mortality.” In the second study, also published in BMJ, a team of researchers at Stanford and several universities in Europe presented a more nuanced view of vitamin D. They concluded there was “suggestive evidence” that high vitamin D levels protect against diabetes, stroke, hypertension and a host of other illnesses. But they also said there was no “highly convincing” evidence that vitamin D pills affected any of the outcomes they examined. The second study also looked at bone health. While Vitamin D had long been believed to help prevent osteoporosis fractures from falls, But Duffy MacKay, a spokesman for the Council for Responsible Nutrition, a supplement industry trade group, said that vitamin D is not easily obtained through food alone, and noted that exposure to sunlight has its dangers. He said he agreed with Dr. Franco that more research was needed to identify “an optimal dose and duration” of vitamin D. “But there is enough positive research currently to indicate that people should be supplementing with vitamin D for a variety of positive health outcomes,” he added./end