The idea made so much sense that it was accepted almost without question: Vitamin D pills can protect bones from fractures. After all, the body needs this vitamin for the intestines to absorb calcium, which bones need to grow and stay healthy.
However, in the first large randomized controlled trial, funded by the US government, researchers report that vitamin D pills taken with or without calcium have no effect on bone fracture rates.
The results, published in The New England Journal of Medicine, apply to people with osteoporosis and even those whose blood tests reveal a vitamin D deficiency.
These results followed other findings from the same study that found no support for a long list of purported benefits of vitamin D supplements.
So for those who take vitamin D supplements and the labs that do more than 10 million vitamin D tests a year, an editorial published alongside the journal gives advice: stop.
“Providers should stop tracking 25-hydroxyvitamin D levels or recommend vitamin D supplements, and people should stop taking vitamin D supplements to prevent serious illness or prolong life,” wrote Steven R. Cummings, researcher. from the California Pacific Medical Center Research Institute, and Clifford Rosen, a senior scientist at the Maine Medical Research Institute.
There are exceptions, they say: People with conditions like celiac or Crohn’s disease need vitamin D supplements, as do those who live in conditions where they are deprived of sunlight and may not get any minerals from foods that are routinely supplemented with vitamin D. D, such as cereals and dairy products.
Such a severe state of vitamin D deprivation, however, is “very difficult to occur in the general population,” Cummings said.
The two scientists know that in making such strong claims they are facing vitamin marketers, testing labs and people who claim that consuming vitamin D, often in large amounts, can cure or prevent a wide range of diseases.
The study involved 25,871 participants — men age 50 and older and women age 55 and older — who were instructed to take either 2,000 IU (international units) of vitamin D a day or a placebo.