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More than half of adults in the U.S. take some type of vitamin each day – a number that has grown steadily over the past 20 years, according to the U.S. Centers for Disease Control.



One of the most popular is vitamin D. Over the past 10 years, doctors have worried that people living in cold climates don’t absorb enough sunlight to prompt their bodies to manufacture its own vitamin D. Across the medical establishment, there was a push to screen patients for vitamin D deficiencies.

But the evidence is mounting that vitamin D supplements are not as helpful as we once believed. A new, large systematic review published this month found that vitamin D does not prevent bone fractures or falls.

To come to this conclusion, researchers analyzed data from 81 randomized controlled trials involving more than 53,000 participants. The analysis found that vitamin D does not have any meaningful effect on bone mineral density. And these data were so strong that the authors concluded there is no need for future studies on this topic.

This latest review builds on recommendations published in 2013 by the U.S. Preventative Services Task Force that healthy, postmenopausal women should not take Vitamin D and calcium supplements to prevent fractures.

The task force is made up of an independent panel of medical experts, who reviewed more than 100 studies before making their recommendation. The experts found insufficient evidence that taking vitamin D and calcium helps prevents fractures, and found a small risk of increased kidney stones for people who did take the supplements.

The task force's recommendation does not apply to people suffering from osteoporosis or vitamin D deficiencies, or those living in skilled nursing facilities. There is also clear evidence that vitamin D is helpful for some people: For example, growing babies need vitamin D to prevent a condition called rickets.

Cornell nutritionist Patsy Brannon has weighed in on the national debate over vitamin D supplements: "The evidence available is inconsistent, with some studies demonstrating this association while others show no association, and still others show evidence of adverse effects with high blood levels of vitamin D," Brannon told the Cornell Chronicle. “Although we can’t conclude whether low vitamin D is associated with chronic disease, the evidence is clear that these vitamin supplements do not prevent fractures.”

The take-home message: Vitamin D supplements do not help to prevent bone fractures or falls.

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