Calcium and Vitamin D Cut Hip Fractures 16 Percent. The Authors Called That 'Little to No Meaningful Benefit.'

Before they pooled a single trial, the researchers behind a sweeping new review of calcium and vitamin D decided what would count as a win. For hip fractures they set the bar at an absolute reduction of 0.7 percentage points: clear that and the benefit was meaningful, miss it and it was not. Then they gathered 69 randomized trials and 153,902 adults, pooled the ones testing calcium and vitamin D together, and found the combination cut hip fractures by 16 percent. Measured against the number they had chosen for themselves, 16 percent was not enough.

The review, published in the BMJ and back in the news this September under the familiar “millions take them for nothing” framing, delivers a verdict that ran clean across the coverage, from ScienceDaily to the BMJ’s own press office: calcium and vitamin D do “little to no” good against the broken bones they are sold to prevent. On the single supplements, that verdict is earned, and worth saying plainly. Vitamin D alone, across 46 trials, did nothing for fractures. Calcium alone, across 15 trials, did nothing either. That half of the finding lines up neatly with where the guidelines have been heading for years.

Then there is the other half. Alone, the supplements were inert. Together, they were not.

Pooled as a pair, calcium and vitamin D produced a risk ratio of 0.91 for any fracture (95% confidence interval 0.84 to 0.99), 0.84 for hip fractures (0.74 to 0.96), and 0.87 for non-vertebral fractures (0.78 to 0.96). Three separate reductions, each landing on the significant side of the line. Only falls, at 0.92 (0.84 to 1.00), failed to clear it.

So how does a set of statistically significant reductions turn into “little to no meaningful benefit”? Through the second number, the 0.7 percentage points the authors had written down before they started. Each of those reductions was measured against that bar, fell short of it, and was filed under “little to no meaningful effect.”

Donal McNally, a bioengineering reader at the University of Nottingham, did the arithmetic the press releases skipped. The authors’ threshold for a meaningful hip-fracture benefit, he noted, was that 0.7 percentage point reduction set against a baseline hip-fracture risk of 1.3 to 1.8 percent in these populations. Meet a bar like that and you would be more than halving the risk of hip fractures, a benefit no supplement is likely to deliver. With more than 70,000 hip fractures a year in the UK and care costs of roughly £2 billion, McNally argued, a far smaller reduction is plainly worth having.

Emma Duncan, professor of clinical endocrinology at King’s College London, pressed from the other side. The trials pooled here ran mostly on community-dwelling adults who were not at high risk of fracture to begin with, and the authors themselves caveat the usefulness of calcium and vitamin D for some people in some circumstances, residents of care homes among them. Those are the people for whom these supplements were prescribed in the first place. A conclusion drawn on the low-risk general public lands on their nightstands too, and in the flat headline version it can be heard as a single instruction: stop.

None of this arrived out of nowhere. The US Preventive Services Task Force has already given low-dose vitamin D and calcium its “D” grade, the recommend-against grade, for the primary prevention of fractures in community-dwelling postmenopausal women, a position that made the news cycle in December 2024. Read the fine print, though, and the task force stopped well short of “it does not work”: higher doses, and men and premenopausal women, it left at insufficient evidence, unable to call the balance either way. “Low-risk people at low doses do not need it” and “it does not work” are different sentences, and only one of them is what these tables show.

The framing is the tell. A finding that a cheap, over-the-counter supplement does less than the label promises gets the full “millions wasting their money” treatment. The statistically significant hip-fracture reduction sitting in the very same dataset gets a threshold and a shrug. That is a choice about what to put in the headline, and it steers a reader toward the two-dollar bottle she can toss rather than the more expensive question underneath it: what actually keeps an old woman’s hip from breaking, and who is studying it in the people most likely to break one.

Massé and colleagues set their bar, pooled their trials, and produced a result that was, for the combination at least, both statistically significant and, by the bar they had set themselves, not meaningful enough to count. The bar was theirs to set. The 16 percent was already in the data.

Sources

1. The BMJ – Massé et al., calcium, vitamin D, or combined supplementation for the primary prevention of fractures and falls (2026)
2. Science Media Centre – expert reaction (McNally, Duncan) to the vitamin D/calcium meta-analysis
3. Healio – Calcium, vitamin D supplements do not lower risk for fractures or falls (risk ratios, author quotes)
4. ScienceDaily – Millions take calcium and vitamin D for bone health. A major review finds little benefit
5. USPSTF – Vitamin D, calcium, or combined supplementation for the primary prevention of fractures in adults