A large clinical trial found that taking vitamin D supplements doesn’t lower a healthy person's risk of breaking a bone, according to a new study published in the New England Journal of Medicine.
Vitamin D carries out many important jobs in your body, one of which is helping to absorb calcium, a vital mineral for strong and happy bones. While supplementing diets with vitamin D may be important for people with a deficiency, low bone mass, or osteoporosis, this latest research discovered that the average healthy person’s bones benefit very little from popping a vitamin D pill each day.
“Overall, the results from this large clinical trial do not support the use of vitamin D supplements to reduce fractures in generally healthy US men and women,” Meryl LeBoff, lead author and Chief of the Calcium and Bone Section in the Endocrine Division at Brigham and Women’s Hospital, said in a statement.
“These findings do not apply to adults with vitamin D deficiency or low bone mass or osteoporosis. Most participants in the trial were not deficient and may have already reached the vitamin D level needed for bone health. Our ongoing studies are focusing on whether free vitamin D levels or genetic variation in vitamin D absorption, metabolism, or receptor function will provide information about individuals who may benefit from supplemental vitamin D on musculoskeletal health,” explained LeBoff.
To reach these findings, scientists from Harvard Medical School piled through data from a pre-existing study called the VITamin D and OmegA-3 TriaL (VITAL), which initially set out to look at cardiovascular and cancer outcomes.
The trial also ended up accumulating a huge amount of information on vitamin D supplementation and other health problems. For this latest study, the researcher looked at a data set of almost 26,000 adults who were followed for five years. The overwhelming majority of participants had healthy vitamin D levels, with just 2.4 percent having levels low enough to be called a severe deficiency.
In total, 1,991 fractures were documented among 1,551 of the participants. Crucially, supplemental vitamin D3 (2,000 IU/day) had no impact on the number of bones broken compared to the placebo group.
Previous studies on vitamin D and bone health have reached similar conclusions. One study found that too much vitamin D may actually harm bones, and not help them. However, there have been some positive findings that have muddied the water.
Vitamin D has gained a reputation for being one of the few supplements that healthy people should be taking. However, a number of recent studies have chucked cold water on the vitamin D bandwagon.
A paper from 2021 concluded that vitamin D supplements do not protect most people from developing colds, flu, and other acute respiratory infections – although they could help to ease them. A number of previous findings from the VITAL project have concluded that vitamin D pills didn't prevent heart attacks, strokes, or cancer either, although they did appear to potentially reduce the risk of cancer-related death
On the flip side, another study published this year found that daily vitamin D supplements could reduce the rate of autoimmune disease by 22 percent in the over-50s.