But a large study, published in the New England Journal of Medicine, found that this popular supplement may not protect them from bone fractures at all.
Previous results from the same dataset, consisting of 25,871 participants in a randomized and controlled VITAL trial, also showed that vitamin D supplements had no impact on the risk of various cancers or heart disease. They also did not reduce migraine or slow cognitive decline, according to other VITAL studies.
In an editorial, the researchers wrote that health care providers should stop recommending vitamin D supplements because the study findings and other trials show that they don’t “prevent major diseases or extend life.”
However, some experts say they will continue to recommend vitamin D supplements.
The study didn’t evaluate the effect of vitamin D combined with calcium supplements, but providers generally prescribe both at once, according to Edward Silverman, MD, an orthopedic surgeon with HCA Florida Mercy Hospital, who was not involved in the study.
“This study didn’t show an effect on fracture risk. But that doesn’t necessarily mean that we should abandon the use of vitamin D in general,” Silverman said.
Until researchers examine different doses of vitamin D with or without calcium, he said “the jury’s still out” on the use of supplements in preventing fracture risk.
Margaret Nachtigall, MD, a clinical associate professor at NYU Langone Health, said that people who have vitamin D deficiency, osteoporosis, or low bone mass would still benefit from taking vitamin D.
“I still am recommending it for patients, especially if they’re not getting exposed to the sun, or they potentially could have a low vitamin D level,” she told Verywell.
Can You Take Too Much Vitamin D?
Vitamin D supplements are generally not harmful. In the United States, the recommended daily intake of vitamin D is 600 IU for most people and 800 IU for adults over the age of 70. The safe maximum daily intake for people ages 9 and above is 4,000 IU (100 mcg).
But it is possible to overdose on vitamin D. At the advice of a nutritionist, a middle-aged man had a vitamin cocktail daily: 150,000 IU of vitamin D along with higher than the recommended amount of omega-3, folate, and vitamin B3, among others.
He went to the hospital after experiencing nausea, leg cramps, diarrhea, weight loss, thirst, and other symptoms.
However, it is rare for an average person to get vitamin D toxicity, according to Silverman. “You have to be taking huge doses every day for a long period of time,” he said.
Vitamin D Alternatives?
Aside from vitamin D and calcium, research has shown that consistent physical activity is crucial in improving bone density. Drinking alcohol only in moderation, smoking, and eating a balanced diet can all help maintain your bone health as you age.
Preventing falls is one of the best ways to prevent fractures in older adults, Silverman added. Removing tripping hazards and getting a vision test can help them avoid accidental falls.
In addition to these preventative measures, experts continue to emphasize the importance of vitamin D for people at risk of a severe deficiency.
Women who have entered menopause, for instance, would experience rapid bone loss because of a dramatic drop in estrogen levels. People with darker skin, obesity, or a history of fragility fractures could also benefit from a boost in vitamin D.
