Low D is for Death
The study, published in the Archives of Internal Medicine, is the latest to show the health benefits of vitamin D. Earlier research found it can guard against osteoporosis and may offer protection from breast and colon cancer, heart disease and dementia. This study analyzed health records of more than 13,000 Americans and found those with the lowest vitamin D blood levels had a 26% higher risk of death over eight years than those with the highest levels. Reinhold Vieth, a nutritional sciences professor at University of Toronto, said this is one more study "to show that higher vitamin D nutrition increases life expectancy."
People produce vitamin D when ultraviolet light from sunshine hits their naked skin. The nutrient, important for cell growth and boosting the immune system, is also found in some fish, fortified dairy products and nutritional supplements.
Vieth, a top expert in vitamin D nutrition, said adults may want to consider taking a daily supplement to boost their levels.
In winter, Canadians average a vitamin D blood level of about 17.8 nanograms per milliliter -- the same level considered to confer an increased risk of death in this study, said Vieth.
According to Dr. Erin Michos, study co-author and assistant professor of medicine at Johns Hopkins School of Medicine, the study provides additional evidence for health officials to consider adding vitamin D deficiency as a distinct risk factor for heart disease.
"We found that even after you take into account roughly 30 different factors that are risk factors for heart disease, such as age, high blood pressure, cholesterol, diabetes, smoking, body mass index and kidney disease, that having low vitamin D levels independently conferred a 26% increase risk of dying from any cause over and above all of these known cardiac risk factors," Michos told the Star.
She cautioned the results do not prove taking a vitamin D supplement could prevent a heart attack or that low levels caused death from heart attack. Of the 1,806 study participants who died, 777 died of heart disease, of whom about 400 were deficient in vitamin D.
From the August 18, 2008, Prepared Foods e-Flash