Vitamin D supplements do not help the other condition, research shows

The idea made so much sense that it was accepted almost without question: vitamin D pills protect bones from fractures. After all, the body needs the vitamin to absorb calcium in the intestine for bones to grow and be healthy.

But now, in the first large randomized controlled trial 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, even those whose blood tests show vitamin D deficiency.

These findings follow other findings from the same study that do not support the long list of 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 with the paper has some advice: Stop.

“Providers should stop screening for 25-hydroxyvitamin D levels or recommend vitamin D supplements, and people should stop taking vitamin D to prevent major diseases or prolong life,” wrote Drs. Stephen R. Cummings, a researcher at the California Pacific Medical Center Research Institute and Dr. Clifford Rosen, a senior scientist at the Maine Medical Research Institute. Dr. Rosen is editor of The New England Journal of Medicine.

There are exceptions, they say: People with conditions like gluten disease or Crohn’s disease who live in sun-deprived conditions and can’t get any minerals from regular vitamin D-fortified foods need vitamin D supplements. , such as grains and dairy products.

Such severe vitamin D deficiency is “very difficult for the general population,” says Dr. Cummings said.

The two scientists know that making such strong claims has appealed to vitamin vendors, testing labs and advocates, who often believe that taking large amounts of vitamin D can cure or prevent a variety of diseases and even help people live longer.

Doctors often check vitamin D levels as part of a blood test.

In the study, 25,871 participants—men aged 50 and older and women aged 55 and older—were assigned to take 2,000 international units of vitamin D or a placebo daily.

The study was part of a comprehensive vitamin D study called VITAL. It began after an expert panel funded by the National Institutes of Health and now convened by the National Academy of Medicine, a nonprofit organization, studied the health effects of vitamin D and found little evidence. The panel members had to come up with a minimum daily requirement for the vitamin, but found that many of the clinical trials examining the topic were insufficient, and they questioned whether claims that vitamin D improves health are true.

The prevailing opinion at the time was that vitamin D prevented bone fractures. Researchers thought that when vitamin D levels were low, parathyroid hormone levels would increase, causing bone damage.

Dr. Rosen said those concerns prompted him and other members of a National Academy of Medicine panel to set what he called a goal of 20 nanograms per milliliter for vitamin D levels and advise people to get 600 nanograms. 800 international units of vitamin D to achieve this goal.

Laboratories in the United States then arbitrarily set 30 nanograms per milliliter as the cutoff for normal vitamin D levels, which is so high that almost the entire population is considered vitamin D deficient.

The hypothesized relationship between vitamin D and parathyroid levels has not been proven in subsequent studies, Dr. said Rosen. But uncertainty persisted, so the National Institutes of Health funded the VITAL trial to get definitive answers about vitamin D’s relationship to health.

The first part of VITAL, previously published, found that vitamin D did not prevent cancer or cardiovascular disease in trial participants. Nor did it prevent falls, improve cognitive function, 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 as long.

Dr. JoAnn Manson, chief of preventive medicine at Harvard Medical School’s Brigham and Women’s Hospital and leader of the pivotal VITAL trial, said the study was so large it included thousands of people who had osteoporosis or were thought to have low vitamin D levels. not enough.” This allowed the investigators to determine whether the supplement benefited fracture reduction.

“It surprises a lot of people,” said Dr. Manson said. “But we seem to need low to moderate amounts of the vitamin for bone health. Big sums don’t bring big benefits.”

The first author and principal investigator of the bone study, Dr. Brigham and Women’s Hospital Osteoporosis Specialist Meryl S. Leboff said he was surprised. He expected profit.

But he cautioned that the study did not address whether people with osteoporosis or low bone mass should take vitamin D and calcium along with their anti-osteoporosis drugs. Professional guidelines say they should take vitamin D and calcium, and she continues to adhere to them in her practice.

Dr. Dolores Shoback, MD, an osteoporosis specialist at the University of California, San Francisco, also recommends taking vitamin D and calcium for patients with osteoporosis and low bone mass.

It’s “a simple intervention and I’ll prescribe it,” he said.

Others go a little further.

Dr. Sandeep Khosla, a professor of medicine and physiology at the Mayo Clinic, said that because vitamin D has “no harm or no benefit,” he recommends 600 to 800 mg of it to his osteoporosis patients. units per day in the National Academy of Medicine report.

“I still tell my family and friends who don’t have osteoporosis to take a multivitamin a day to avoid vitamin D deficiency,” she said.

Dr. Khosla follows this advice himself. Many multivitamin pills now contain 1,000 units of vitamin D, he added.

But Dr. Cummings and Dr. Rosen remains firm, even 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 need to take vitamin D.”

And Dr. Rosen, who signed the National Academy of Medicine report, became a vitamin D therapeutic nihilist.

“I don’t believe in 600 units anymore,” he said. “I don’t believe you need to do anything.”

Leave a Comment

Your email address will not be published.