More research suggests it’s time to ditch the vitamin D obsession.
Taking high doses of the “sunshine vitamin” does not reduce the risk of broken bones in normally healthy older Americans, researchers reported Wednesday.
It’s the latest in a string of disappointments about nutrients that were once expected to have a wide range of protective effects. The same study of nearly 26,000 people found that high doses of vitamin D pills did not prevent heart disease, cancer or memory loss.
And while getting enough vitamin D is important for strong bones, “more is not better,” says Dr. Meryl LeBeouf of Boston’s Brigham and Women’s Hospital, lead author of the study.
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About one-third of Americans age 60 and older take supplements and more than 10 million blood tests are performed annually for vitamin D levels — despite years of controversy over whether the average senior needs it.
The new results — which add to other trials with similar results — should end that debate, Dr. Steven Cummings of California Pacific Medical Center and Clifford Rosen of Maine Medical Center Research Institute in a commentary in the medical journal.
“People should stop taking vitamin D supplements to prevent major diseases” — and doctors should stop routine screenings that fuel anxiety, the pair concluded. They did not participate in the latest study.
How Much Vitamin D Should People Get? The US recommends 600 to 800 international units per day to ensure that everyone, young and old, gets enough. Our skin makes vitamin D from sunlight, which can be tough in winter. Milk and some other foods are fortified with helpful nutrients.
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The big question is whether more than the recommended amount is good for preventing fractures or other ailments. To address conflicting scientific reports, Brigham and Women’s Preventive Medicine Chief Dr. JoAnn Manson initiated the largest study of its kind to track a variety of health outcomes among nearly 26,000 generally healthy Americans age 50 or older. The latest results compared bone fractures in those who took high doses — 2,000 international units of the most active form of vitamin D, known as D-3 — or dummy pills daily for five years.
The supplements did not reduce the risk of broken hips or other bones, LeBeouf reported in the New England Journal of Medicine. While vitamin D and calcium work best together, the 20% of study participants who took a calcium supplement didn’t benefit either, she said. A small number of study participants did not have low blood levels of vitamin D.
However, LeBoff cautioned that the study did not include people with osteoporosis or other disorders that cause bone thinning, or with severe vitamin D deficiencies that require supplements. More research is needed to determine whether there are additional high-risk groups that could benefit, Manson said.
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Overall, “these findings overturn theory and cast doubt on the value of routine screening for vitamin D blood levels and blanket recommendations for supplementation,” Manson said. Most people find that “spending time outdoors, being physically active and eating a heart-healthy diet can have major health benefits”.