More research suggests it’s time to ditch the vitamin D craze.
Taking high doses of the “sunshine vitamin” does not reduce the risk of breaking bones in generally healthy older Americans, researchers reported Wednesday.
It’s the latest in a series of disappointments about a nutrient once expected to have broad protective effects. That same study of nearly 26,000 people had already found that taking lots of vitamin D pills didn’t prevent heart disease, cancer or memory loss either.
And while getting enough vitamin D is important for strong bones, “more is not better,” said Dr. Meryl LeBoff of Brigham and Women’s Hospital in Boston, the study’s lead author.
An estimated one-third of Americans age 60 and older take the supplements, and more than 10 million blood tests are done each year to determine vitamin D levels, despite years of controversy over whether the average adult needs
The most recent findings, added to other trials with similar results, should end this debate, wrote Drs. Steven Cummings of the California Pacific Medical Center and Clifford Rosen of the Maine Medical Center Research Institute in a medical journal commentary.
“People should stop taking vitamin D supplements to prevent major diseases,” and doctors should stop routine testing that worries them, the pair concluded. They did not participate in the last study.
How Much Vitamin D Should People Get? The United States recommends 600 to 800 international units per day to ensure that everyone, young and old, is getting enough. Although our skin produces vitamin D from sun exposure, this can be harder in the winter. Milk and some other foods are fortified with the nutrient to help.
The bigger question was whether more than the recommended amount might be better, to prevent fractures or perhaps other disorders as well. To address conflicting scientific reports, Brigham and Woman’s Chief of Preventive Medicine Dr. JoAnn Manson initiated the largest study of its kind to track a variety of health outcomes in nearly 26,000 Americans generally healthy around 50 years or older. The latest results compared bone fractures in those who took a high dose (2,000 international units of the most active form of vitamin D, called D-3) or dummy pills every day for five years.
The supplements did not reduce the risk of breaking hips or other bones, LeBoff reported in the New England Journal of Medicine. Although vitamin D and calcium work best together, he said, even the 20 percent of study participants who also took a calcium supplement did not benefit. Neither did the small number of study participants who had low blood levels of vitamin D.
Still, LeBoff cautioned that the study did not include people who may need supplements because of osteoporosis or other bone-thinning disorders, or those with severe vitamin D deficiencies. And Manson said more are needed research to see if there are additional high-risk groups that could benefit.
Overall, “these findings overturn dogma and call into question the value of routine screening of vitamin D blood levels and general recommendations for supplementation,” Manson said. “Spending time outdoors, being physically active and eating a heart-healthy diet will lead to greater health gains” for most people.
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The Associated Press Department of Health and Science is supported by the Department of Science Education at the Howard Hughes Medical Institute. The AP is solely responsible for all content.