Study casts more doubt on high-dose vitamin D supplementation
Multiple studies suggest it’s time to give up the vitamin D craze.
Taking high doses of the “sunshine vitamin” does not reduce fracture risk in healthy older Americans, The researchers reported Wednesday.
This is the latest in a string of disappointments over a nutrient once hoped for broad-spectrum protection. The same study of nearly 26,000 people found that many vitamin D pills does 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 LeBoff of Boston’s Brigham and Women’s Hospital, lead author of the study. know.
An estimated one-third of Americans age 60 and older take supplements, and more than 10 million blood tests for vitamin D are performed each year — despite years of controversy over whether the average adult jar is needed or not.
The latest findings — added to other trials with similar results — should end that debate, Dr. 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 serious illnesses”—and doctors should stop worrying routine checkups, the couple concluded. They were not involved in the latest research.
Read more: What science says about the health benefits of vitamins and supplements
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, gets enough. While our skin makes vitamin D from sun exposure, that can be more difficult in the winter. Milk and some other foods are fortified with nutrients to help.
The bigger question is whether more than that recommended amount might be better, for preventing fractures or possibly other disorders. To address conflicting scientific reports, Dr JoAnn Manson, Brigham and Woman’s head of preventive medicine, has begun the largest study of its kind to track multiple health outcomes in nearly 26,000 people. America is generally healthy in their 50s and older. The latest results compare fractures in people taking either high doses — 2,000 international units of the most active form of vitamin D, known as D-3 — or dummy pills every day for five years.
Supplements did not reduce the risk of hip or other bone fractures, LeBoff reported in New England Journal of Medicine. While vitamin D and calcium work best together, she says even 20% of study participants who took calcium supplements did not benefit. Nor did a small number of study participants have low blood levels of vitamin D.
However, LeBoff cautions that the study did not include people who may need a supplement because of osteoporosis or other disorders, or who have a severe vitamin D deficiency. And Manson said more research is needed to see if there are other high-risk groups that may benefit.
Overall, “these findings debunk dogma and cast doubt on the value of routine blood vitamin D testing and general recommendations for supplementation,” says Manson. “Spend time outdoorspresent physical activity and there is a heart healthy diet will lead to improved health” for most people.
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