Taking both calcium and vitamin D supplements cuts the risk of broken bones by 15% for middle-aged and older adults.
See the scientific wording
Supplementation with calcium and vitamin D reduces the risk of total fractures by 15% in middle-aged to older adults, as indicated by a meta-analysis of eight randomized controlled trials including 30,970 participants.
Very strong evidence
Randomized trialsOne good-quality study supports this claim.
What the research says
1 study reviewedSupporting (1)
Systematic Review With Meta-AnalysisMeta-analysis2016
Taking calcium and vitamin D together was found to lower the chance of breaking a bone by about 15% in older adults, based on a large review of studies.
Contradicting (0)
No contradicting studies found yet
That doesn't mean it's settled — it just means no study has tested the opposite.
Quality-weighted scoring: we follow the GRADE framework — each study is rated High, Moderate, Low, or Very Low based on study design, methodology rigor, and risk of bias. A single high-quality RCT can outweigh several weaker observational studies.
Scores reflect study quality, not just count.
Vitamin D helps the body take in calcium from food. With enough calcium in the blood, bones can stay strong and repair themselves. Strong bones are less likely to break.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting study
How Fit Body Science checks a claim
- 1
We isolate the claim
Health advice from videos, articles and studies is broken down into single, testable claims.
- 2
We find the research
Each claim is matched against peer-reviewed studies, with every source cited by DOI.
- 3
We grade the evidence
Studies are scored on methodology, statistical rigor, transparency and publication quality.
The fitness and health internet is full of confident claims. We check them against real research.
Every claim on this site is traced back to peer-reviewed studies, scored on methodology and reporting quality, and given a verdict you can audit yourself — sources, DOIs and all.
- Full evidence breakdown and mechanism chains
- Ask our AI anything about a claim or its studies
- Get notified when new research changes a verdict
Taking both calcium and vitamin D supplements cuts the risk of broken bones by 15% for middle-aged and older adults.
Mechanism
1 studyVitamin D helps the body use calcium to build strong bones. When bones are strong, they don't break as easily. So taking calcium and vitamin D together makes bones healthier and lowers the chance of breaking a bone.
Vitamin D helps the body take in calcium from food. With enough calcium in the blood, bones can stay strong and repair themselves. Strong bones are less likely to break.
Vitamin D increases calcium absorption in the intestine.
Adequate serum calcium concentrations are maintained.
Normal bone mineralization occurs, ensuring proper bone density and strength.
Vitamin D supports bone remodeling through the activity of osteoblasts and osteoclasts.
Improved bone strength reduces the risk of total fractures.
Evidence from Studies
Supporting (1)
Community contributions welcome
Calcium plus vitamin D supplementation and risk of fractures: an updated meta-analysis from the National Osteoporosis Foundation
Taking calcium and vitamin D together was found to lower the chance of breaking a bone by about 15% in older adults, based on a large review of studies.
Contradicting (0)
Community contributions welcome
Score Breakdown
No multi-axis breakdown available yet. The overall Pro / Against score above is the best signal.
- No clinical evidence is available; the score reflects mechanistic plausibility only.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Systematic Review and Meta-Analysis of Randomized Controlled Trials on Calcium and Vitamin D Supplementation and Fracture Risk in Middle-Aged and Older Adults
Systematic review and meta-analysis of RCTs comparing calcium and vitamin D supplementation to placebo or no treatment, with total fractures as outcome, in middle-aged to older adults (age 50+), with at least 2 years follow-up.
Randomized Controlled Trial of Calcium and Vitamin D Supplementation vs Placebo on Fracture Incidence in Middle-Aged and Older Adults
Two-arm parallel-group RCT with 1,000 participants aged 50+ years, randomized to daily calcium (e.g., 1200 mg) and vitamin D (e.g., 800 IU) or placebo for 3 years, tracking incident total fractures.
Prospective Cohort Study on Calcium and Vitamin D Supplement Use and Fracture Risk in Middle-Aged and Older Adults
Prospective cohort following 10,000 adults aged 50+ for 5 years, recording supplement use and incident fractures, adjusting for confounders (e.g., lifestyle, medical history).
Case-Control Study Comparing Calcium and Vitamin D Supplement Use in Fracture Cases vs Controls
Case-control study with 500 fracture cases and 500 age- and sex-matched controls, assessing self-reported past use of calcium and vitamin D supplements, adjusting for potential confounders.