The idea made so much sense that it was almost unquestionably accepted: Vitamin D pills can protect bones from fractures. After all, the body needs vitamins to absorb calcium, which is essential for bones to grow and stay healthy.
But now, in the first large randomized controlled study funded by the federal government in the United States, researchers report that vitamin D pills taken with or without calcium have no effect on bone fracture rates. The results, published Thursday in The New England Journal of Medicine, compared people with osteoporosis and even those whose blood tests found them to be vitamin D deficient.
These results followed other findings from the same study that found no support for the long list of purported benefits of vitamin D supplements.
So, for the millions of Americans who take vitamin D supplements and the laboratories that conduct more than 10 million vitamin D tests each year, an editorial published with the paper has some advice: Wait.
Dr. Steven R., a research scientist in the California Pacific. Cummings wrote, “Providers should stop screening for 25-hydroxyvitamin D levels or recommend vitamin D supplements and people should stop taking vitamin D supplements to prevent major diseases or extend life.” should.” Medical Center Research Institute, and Dr. Clifford Rosen, a senior scientist at the Maine Medical Research Institute. Dr. Rosen is the editor of The New England Journal of Medicine.
There are exceptions, he says: People with conditions like celiac or Crohn’s disease need vitamin D supplements, as do those who live in situations where they’re deprived of sunlight and can’t get any minerals from the foods they eat. who are regularly supplemented with vitamin D. , such as cereals and dairy products.
Entering such a severe vitamin D-deprived state is “very difficult to do in the general population,” Dr. Cummings said.
Both scientists know that in making such strong statements they are taking on vitamin vendors, testing labs and advocates who have claimed that taking vitamin D frequently in large amounts can cure or prevent a wide variety of diseases and It can even help people live longer.
Doctors often check vitamin D levels as part of routine blood tests.
The study involved 25,871 participants — men age 50 and older and women age 55 and older — who were assigned to take either 2,000 international units of vitamin D or a placebo each day.
The research was part of a wider vitamin D study called VITAL. It was funded by the National Institutes of Health and began after an expert group convened by the National Academy of Medicine, a non-profit organization, examined the health effects of vitamin D supplements and found little evidence. Members of the expert group should have come up with a minimum daily requirement for the vitamin, but they found that most clinical trials that studied the subject were insufficient, prompting them to ask whether there is any truth to the claims that vitamin D has improved health.
The prevailing opinion at the time was that vitamin D was likely to prevent bone fractures. Researchers thought that as vitamin D levels fell, levels of parathyroid hormone, harmful to bones, would rise.
Dr Rosen said those concerns prompted him and other members of the National Academy of Medicine’s expert group to set an “arbitrary value” of 20 nanograms per milliliter of blood as a target for vitamin D levels and advise people to achieve inspired to. 600 to 800 units of international vitamin D supplements are used to achieve that goal.
Labs in the United States arbitrarily set 30 nanograms per milliliter as the cutoff point for normal vitamin D levels, a reading so high that almost everyone in the population would be considered vitamin D deficient.
Dr. Rosen said the presumed association between vitamin D and parathyroid levels has not persisted in subsequent research. But uncertainty remained, so the National Institutes of Health funded a significant trial to get some concrete answers about vitamin D’s health relationship.
The first part of the previously published VITAL found that vitamin D did not prevent cancer or heart disease in trial participants. Nor does it prevent falls, improve cognitive function, reduce atrial fibrillation, alter body composition, reduce the frequency of migraines, improve stroke outcomes, prevent macular degeneration Or reduces knee pain.
Another large study in Australia found that people who took the vitamin did not live longer.
D., chief of preventive medicine at Brigham and Women’s Hospital at Harvard Medical School and chief critical trial leader. Joan Manson said the study was so large that it considered thousands of people with osteoporosis or low levels of vitamin D. or “inadequate.” This allowed the investigators to determine that they also found no benefit for fracture reduction from the supplement.
“It will surprise many people,” Dr. Manson said. “But we think that only small to moderate amounts of the vitamin are needed for bone health. Large amounts do not provide much benefit.”
The first author and principal investigator of the bone study, Dr. Merrill S., an osteoporosis specialist at Brigham and Women’s Hospital. LeBoff said she was surprised. He expected profit.
But she cautioned that the study does not address the question of whether people with osteoporosis or low bone mass should take vitamin D and calcium along with osteoporosis medications. Professional guidelines say she should take vitamin D and calcium, and she will continue to follow them in her practice.
Dr. Dolores Shoback, an osteoporosis specialist at the University of California, San Francisco, will also continue to advise patients with osteoporosis and low bone mass to take vitamin D and calcium.
It is “a simple intervention and I will continue to write it,” she said.
Others go a little further.
Dr. Sandeep Khosla, a professor of medicine and physiology at the Mayo Clinic, said that since vitamin D “will do little or no harm and may be of benefit,” he will continue to advise his patients with osteoporosis to take it, recommending 600. up to 800 units a day, reports the National Academy of Medicine.
“I would still tell my family and friends that those who do not have osteoporosis take a multivitamin a day to make sure they are not vitamin D deficient,” he said.
Dr. Khosla himself follows that advice. He noted that many multivitamin tablets now contain 1,000 units of vitamin D.
But Dr. Cummings and Dr. Rosen also stands firm, questioning the idea of vitamin D deficiency for healthy people.
“If Vitamin D Doesn’t Help, What Is Vitamin D Deficiency?” Dr. Cummings asked. “That means you should be taking vitamin D.”
And Dr. Rosen, who signed the National Academy of Medicine report, has become a vitamin D therapeutic nihilist.
“I don’t believe in 600 units anymore,” he said. “I don’t think you should do anything.”
(This story has not been edited by seemayo staff and is published from a rss feed)