The idea was so logical that it was almost undoubtedly acceptable: Vitamin D pills could protect bones from fractures. After all, the body needs a vitamin for the intestines to absorb calcium, which bones need to grow and maintain their health.
But now, in the first large, randomized controlled study in the United States, funded by the federal government, researchers report that vitamin D pills taken with or without calcium have no effect on bone fracture rates. The findings, published Thursday in the New England Journal of Medicine, apply to people with osteoporosis and even those whose blood tests have deemed them to be vitamin D deficient.
These results followed other conclusions from the same study that found no support for the long list of purported benefits of vitamin D supplementation.
So, for the millions of Americans who take vitamin D supplements and the labs that perform more than 10 million vitamin D tests each year, an editorial published alongside the paper has some advice: STOP.
Dr. wrote. Cummings, a research scientist at the California Pacific Medical Center, and Dr. Clifford Rosen, a senior scientist at the Maine Institute of Medical Research. Dr. Rosen is an editor for the New England Journal of Medicine.
There are exceptions, they say: People with conditions such as celiac disease 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 of the minerals from foods that are highly supplemented. Vitamin D routine. , such as cereals and dairy products.
Getting into such a severe state of vitamin D deprivation “is very difficult to do in the general population,” said Dr. Cummings said.
The two scientists know that by making such strong statements, they are dealing with vitamin vendors, testing labs and advocates who have claimed that taking vitamin D, often in huge quantities, can treat or prevent a variety of diseases and even help people live. for longer.
Doctors often check vitamin D levels as part of routine blood tests.
The study included 25,871 participants — men 50 and older and women 55 or older — who were assigned to take 2,000 IU of vitamin D per day or a placebo.
The research was part of a comprehensive study of vitamin D called VITAL. It was funded by the National Institutes of Health and began after a group of experts convened by what is now the National Academy of Medicine, a nonprofit organization, examined the health effects of vitamin D supplementation and found little evidence. Members of the expert panel were supposed to come up with a minimum daily requirement for the vitamin, but they found that most of the clinical trials that studied the topic were insufficient, leaving them to question whether there is any truth to the claims that vitamin D improves health.
The prevailing view at the time was that vitamin D was likely to prevent bone fractures. Researchers believe that as vitamin D levels drop, parathyroid hormone levels will increase to the detriment of bone.
Dr. Rosen said these concerns led him and other members of the National Academy of Medicine’s expert group to set what he called a “random value” of 20 nanograms per milliliter of blood as a target for vitamin D levels and advise people to get 600 to 800 IU from a vitamin supplement. d to achieve this goal.
Then laboratories in the United States arbitrarily set 30 nanograms per milliliter as the cut-off point for normal vitamin D levels, a reading so high that almost the entire population would be considered vitamin D deficient.
The putative relationship between vitamin D and parathyroid levels has not been put off in subsequent research, said Dr. Rosen said. But uncertainty persisted, so the National Institutes of Health funded the VITAL trial to get some solid answers about vitamin D’s relationship to health.
The first part of VITAL, published previously, found that vitamin D did not prevent cancer or cardiovascular disease in trial participants. Nor did it prevent falls, improve cognitive performance, reduce atrial fibrillation, change body composition, reduce migraine frequency, improve stroke outcomes, protect against macular degeneration, or reduce knee pain.
Another large study in Australia found that people who took the vitamin did not live longer.
Dr. JoAnn Manson, chief of preventive medicine at Harvard Medical School’s Brigham and Women’s Hospital and head of the VITAL main trial, said the study was so large that it included thousands of people with osteoporosis or with vitamin D levels in a range considered low or “inadequate.” ” This allowed the investigators to determine that they received no breakage-reducing benefit from the supplement.
“This will surprise many,” Dr. Manson said. But it seems we only need small to moderate amounts of vitamins for bone health. Large amounts do not confer greater benefits.”
The first author of the bone study and principal investigator Dr. Meryl S. LeBeouf, an osteoporosis expert at Brigham and Women’s Hospital, said she was surprised. She was expecting a benefit.
But she cautioned that the study did not address the question of whether people with osteoporosis or low bone mass who do not reach the healthy state should take vitamin D and calcium, along with osteoporosis medications. Professional guidelines state that they should take vitamin D and calcium, and you will continue to adhere to both in your own practice.
Dr. Dolores Schupak, an osteoporosis expert 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 was “a minor intervention and I will continue to prescribe it,” she said.
Others go a little further.
Dr. Sandeep Khosla, MD, professor of medicine and physiology at the Mayo Clinic, said that because vitamin D “will cause little or no harm and may have benefits,” he will continue to advise his patients with osteoporosis to take it, recommending 600 to 800 units per day per the National Academy of Medicine report.
“I will keep telling my family and friends who don’t have osteoporosis to take a daily multivitamin to make sure they don’t have a vitamin D deficiency,” he said.
Dr. Khosla follows this advice himself. He added that many multivitamins now contain 1,000 units of vitamin D.
But Dr. Cummings and Dr. Rosen is still assertive, even skeptical about the idea of a vitamin D deficiency for healthy people.
“If Vitamin D Doesn’t Help, What Is Vitamin D Deficiency?” Dr. asked Cummings. “That means you have to take vitamin D.”
friendship. Rosen, who signed the National Academy of Medicine report, became a therapeutic nihilist with vitamin D.
“I don’t believe 600 units anymore,” he said. “I don’t think you should do anything.”