Do Calcium and Vitamin D Supplements Prevent Fractures and Falls? The Latest Evidence
A recent article in the BMJ examines whether calcium supplements, vitamin D supplements, or a combination of both help prevent fractures and falls in adults.
Overview
The researchers conducted a systematic review and meta-analysis of randomised controlled trials to determine whether supplementation with calcium, vitamin D, or calcium plus vitamin D reduces the risk of fractures or falls in adults who are not receiving osteoporosis drug treatment. The study included 69 trials involving 153,902 participants. The main conclusion was that these supplements provide little to no clinically meaningful benefit for preventing fractures or falls in the general adult population.
Why the study was conducted
Falls and fractures are major public health problems, particularly among older adults. Falls are a leading cause of injury, disability, hospitalisation, loss of independence, and healthcare costs. Fractures, especially hip fractures, are associated with pain, reduced quality of life, functional decline, residential care placement, and increased mortality.
Because calcium and vitamin D are important for bone and muscle health, supplementation has long been promoted to prevent fractures and falls. Many clinical guidelines still recommend vitamin D, with or without calcium, despite inconsistent evidence from previous reviews.
What the researchers did
The authors searched major medical databases, trial registries, conference abstracts, and references up to 19 February 2025. They included randomised controlled trials comparing:
- Calcium vs placebo/no treatment
- Vitamin D vs placebo/no treatment
- Calcium + vitamin D vs placebo/no treatment
Participants had to be adults aged 18 years or older and not receiving osteoporosis medications.
The primary outcome was any fracture. Secondary outcomes included:
- Hip fractures
- Non-vertebral fractures
- Vertebral fractures
- Risk of falling
- Total number of falls
Who was studied?
| Characteristic | Details |
|---|---|
| Participants | 153,902 adults across 69 randomised controlled trials |
| Living situation | Community-dwelling: 87% of trials Residential care: 13% of trials |
| Risk profile | Not at high risk of fractures or falls: 73% of trials High-risk populations: 28% of trials |
| Typical participant | Median age 71 years (IQR 63.8–76.9 years). Most participants were 65 years or older (84% of trials) Only a small minority had previous fractures (6%), previous falls (4%), or diagnosed osteoporosis (6%) Most participants did not have severe vitamin D deficiency, with only 3% of trials including participants with a mean baseline vitamin D level <25 nmol/L. |
Summarised from the trial characteristics table in the paper.
Main findings
Calcium alone
11 trials, 9,067 participants
Calcium supplementation probably has little to no effect on overall fracture risk.
| Outcome | Result |
|---|---|
| Any fracture | RR 0.91 (95% CI 0.81–1.01) |
| Hip fracture | Very uncertain evidence |
| Non-vertebral fracture | Little to no effect |
| Vertebral fracture | Little to no effect |
| Falls | Little to no effect |
Evidence was mostly moderate certainty.
Vitamin D alone
46 trials, 96,296 participants
Vitamin D supplementation showed essentially no benefit.
| Outcome | Result |
|---|---|
| Any fracture | RR 1.00 (0.95–1.06) |
| Hip fracture | RR 1.13 (1.00–1.27) |
| Non-vertebral fracture | RR 1.01 (0.95–1.06) |
| Vertebral fracture | RR 1.04 (0.66–1.65) |
| Risk of falling | RR 1.01 (0.98–1.04) |
| Total falls | IRR 1.00 (0.95–1.06) |
Key point
These findings were supported by high-certainty evidence.
Calcium plus vitamin D
16 trials, 51,172 participants
The combination showed small statistical reductions in some fracture outcomes, but the benefits were too small to be considered clinically meaningful.
| Outcome | Result |
|---|---|
| Any fracture | RR 0.91 (0.84–0.99) |
| Hip fracture | RR 0.84 (0.74–0.96) |
| Non-vertebral fracture | RR 0.87 (0.78–0.96) |
| Falls | RR 0.92 (0.84–1.00) |
Absolute benefit was tiny
- 1% fewer fractures overall (number needed to treat ? 100)
- 0.3% fewer hip fractures (NNT ? 333)
- 1.6% fewer non-vertebral fractures (NNT ? 63)
Sensitivity analyses: when one influential trial was removed, the apparent benefit largely disappeared.
Summary of the findings
| Supplement | Effect on Fracture and Fall Prevention |
|---|---|
| Calcium | Little to no effect |
| Vitamin D | No meaningful effect |
| Calcium + Vitamin D | Very small statistical benefit, but the absolute benefit was not clinically meaningful |
| Overall conclusion | Routine calcium and/or vitamin D supplementation is not supported for the prevention of fractures or falls in the general adult population. |
Did any groups benefit more?
The authors performed extensive subgroup analyses, including people who were:
- Very elderly
- Living in residential care
- Vitamin D deficient
- Osteoporotic
- With previous fractures or falls
No consistent evidence showed that supplementation worked better in any subgroup. However, evidence for very high-risk populations was more limited, so modest benefits in such groups cannot be completely ruled out.
Why earlier studies seemed more positive
The paper explains that enthusiasm for calcium and vitamin D largely came from an influential early-1990s trial in frail elderly women living in care homes who had:
- Very low vitamin D levels
- Low calcium intake
- High baseline fracture risk
That study showed substantial benefits, but later trials in broader populations generally failed to replicate those results.
Economic implications
The authors note that vitamin D prescribing has increased dramatically despite uncertain benefits. In the UK, prescription costs reportedly rose from £13 million in 2001 to £111 million in 2021.
Potential harms
Although generally considered safe, calcium supplements can cause:
- Constipation
- Bloating
- Abdominal pain
- Cramps
Some studies also suggest possible increases in kidney stones and gastrointestinal-related hospital visits, though the absolute risks are relatively small.
Strengths of the review
- Very large evidence base
- Comprehensive search strategy
- Independent review by multiple researchers
- Use of modern risk-of-bias methods
- Formal assessment of evidence certainty (GRADE)
- Inclusion of recent large trials
Important limitations
- Many trials were relatively short
- Most participants were not severely vitamin D deficient
- Some subgroup analyses were based on few studies
- Control groups often used their own supplements, potentially reducing observed differences
- Results do not apply to people taking osteoporosis medications, who often receive calcium/vitamin D as background therapy
Bottom line
This large, up-to-date BMJ review concludes that routine calcium supplementation, vitamin D supplementation, or combined calcium and vitamin D supplementation is unlikely to provide meaningful protection against fractures or falls for most adults.
The evidence suggests:
| Supplement | Overall conclusion |
|---|---|
| Calcium | Little to no benefit |
| Vitamin D | Little to no benefit |
| Calcium + vitamin D | Very small statistical benefits that are not clinically meaningful |
The authors therefore conclude that the findings do not support routine supplementation for the prevention of fractures and falls in the general adult population.
