Meta-analysisindependent cross-checkabstract checked I-SUP-112 in-depth review
Calcium pills and heart disease: no link found
Association Between Calcium Supplementation and the Risk of Cardiovascular Disease and Stroke: A Systematic Review and Meta-Analysis.
Overview
Sim MG et al.. Heart Lung Circ 2023 · PMID 37743221 · DOI 10.1016/j.hlc.2023.07.008
A 2023 review of 12 trials found no link between calcium pills and heart attacks, strokes or deaths.
Does the study support the specific claim? No · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
To check calcium pills and heart risk in trials.
- How was the study done?
Meta-analysis of randomised trials.
- How many people, animals or samples were studied?
12 trials.
- What was actually found?
No link with heart attack, stroke or death.
- How large was the observed effect?
Not given in abstract.
- What do the results mean in everyday life?
The heart risk of calcium pills, if any, is uncertain.
- What are the study's limitations?
Abstract lacks numbers.
- What does it say about Elawady's specific claim?
Contradicts C-SUP-04.
- Do the results apply to Germany and Europe?
Applicable.
- What can explicitly not be concluded from this study?
Cannot exclude a small risk.
Scientific in-depth review
1. Full reference
- Authors
- Sim MG et al.
- Journal
- Heart Lung Circ
- Year
- 2023
- Identifier
- PMID 37743221 DOI 10.1016/j.hlc.2023.07.008
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
No COI statement in PubMed record
2. Research question
Is calcium supplementation associated with CVD and stroke in RCTs?
3. Study design and population
- Study design
- Meta-analysis – Systematic review and meta-analysis of RCTs
- Population
Adults in RCTs of calcium supplementation
- Country
Multinational
- Period
Search to 6 August 2021
- Sample size
12 RCTs (participant number not stated in abstract)
- Inclusion and exclusion criteria
RCTs of calcium supplementation reporting CVD or stroke
4. Methods and endpoints
- Exposure / intervention
Calcium alone or with vitamin D
- Comparator
Placebo/control
- Endpoints
MI, stroke, heart-failure admission, CV and all-cause mortality
- Statistical methods
Meta-analysis with subgroup analyses
5. Actual results
- Results
Calcium supplementation not associated with myocardial infarction, total stroke, heart-failure admission or cardiovascular/all-cause mortality; subgroups (calcium alone or with vitamin D, female sex, follow-up, region) did not change findings. Effect estimates not given in the abstract.
- Absolute risks
not reported in abstract
- Authors' conclusion
Calcium supplementation was not associated with MI, stroke, heart-failure admission or mortality.
6. Strengths
- Recent RCT-only analysis
- Subgroup by calcium alone vs with vitamin D
7. Weaknesses
- Effect sizes not in abstract
- Overlapping trials with I-SUP-110
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Abstract only.
9. Assessment of the statistical interpretation
Cannot recalculate; no estimates in abstract.
10. Relevance to the specific claim
Directly contradicts a 31% MI increase; includes calcium-alone subgroup.
11. Independent contrary findings
I-SUP-110, I-SUP-111, A-SUP-01, A-SUP-02.
12. Transferability to Germany and Europe
Applicable.
13. Overall methodological judgement
Conflicts with I-SUP-110 despite overlapping trial sets; different inclusion choices explain discrepant results.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | not applicable |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | inconsistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Why overlapping meta-analyses disagree (trial selection, outcome definitions).
15. Linked fact checks
- Calcium supplements without vitamin D raise the risk of myocardial infarction by about 31%, and adding vitamin D does not remove this harm. – Studies contradicting or limiting the claim