Systematic reviewindependent cross-checkabstract only checked★ key study I-SUP-08 in-depth review
USPSTF evidence review 2022
Vitamin and Mineral Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.
Overview
O'Connor EA et al.. JAMA 2022 · PMID 35727272 · DOI 10.1001/jama.2021.15650
Supplements gave little or no protection; beta-carotene harmful; multivitamins slightly fewer cancers.
Does the study support the specific claim? Partly · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Supplement benefits/harms.
- How was the study done?
SR.
- How many people, animals or samples were studied?
739,803.
- What was actually found?
Little benefit; some harms.
- How large was the observed effect?
OR 0.93 MV cancer; 1.20 beta-carotene lung cancer.
- What do the results mean in everyday life?
Supplements are not a prevention strategy.
- What are the study's limitations?
Not for deficiency.
- What does it say about Elawady's specific claim?
Mixed.
- Do the results apply to Germany and Europe?
Applicable.
- What can explicitly not be concluded from this study?
Effects in deficient people.
Scientific in-depth review
1. Full reference
- Authors
- O'Connor EA et al.
- Journal
- JAMA
- Year
- 2022
- Identifier
- PMID 35727272 DOI 10.1001/jama.2021.15650
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Conflict of Interest Disclosures: None reported.
2. Research question
Benefits and harms of vitamin/mineral supplements for CVD and cancer prevention
3. Study design and population
- Study design
- Systematic review – Updated evidence report and systematic review for USPSTF
- Population
Adults without CVD, cancer or known deficiency
- Country
Multinational
- Period
2013–Feb 2022 + prior reviews
- Sample size
84 studies, 739,803
- Inclusion and exclusion criteria
No known deficiency
4. Methods and endpoints
- Exposure / intervention
Vitamins, minerals, multivitamins
- Comparator
Placebo
- Endpoints
Mortality, CVD, cancer, harms
- Statistical methods
Rare-event pooling
5. Actual results
- Results
Multivitamin: any cancer OR 0.93 (0.87–0.99), lung cancer OR 0.75; beta-carotene: lung cancer OR 1.20 (1.01–1.42), CV mortality OR 1.10; vitamin D: mortality OR 0.96 (n.s.); vitamin E: mortality OR 1.02 (n.s.); limited evidence of harms (hip fracture vitamin A, haemorrhagic stroke vitamin E, kidney stones vitamin C, calcium).
- Absolute risks
ARD range for multivitamin cancer −0.2% to −1.2%
- Authors' conclusion
Little or no benefit except small cancer benefit with multivitamins; beta-carotene harmful in high-risk persons.
6. Strengths
- Comprehensive
- No COI
7. Weaknesses
- Excludes deficiency, pregnancy
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
9. Assessment of the statistical interpretation
10. Relevance to the specific claim
C-SUP-01, -02, -03, -06.
11. Independent contrary findings
12. Transferability to Germany and Europe
High.
13. Overall methodological judgement
Best overall evidence summary; supports most archive claims, limits some.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | high |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
15. Linked fact checks
- When popular oral supplements (calcium, beta-carotene, vitamin E, omega-3, multivitamins, glucosamine, selenium, vitamin A) were tested in large long-term placebo-controlled trials, most failed to deliver the promised prevention of disease. – Studies supporting the claim
- Beta-carotene supplements (with or without vitamin A) increased lung cancer and mortality in smokers and asbestos-exposed workers (CARET, ATBC), and the USPSTF recommends against them. – Studies supporting the claim
- High-dose vitamin E (400 IU/day) increases prostate cancer (SELECT, +17%) and may increase all-cause mortality (Miller 2005: +39 per 10,000). – Studies contradicting or limiting the claim
- Multivitamins, iron, folic acid, B6, magnesium, zinc and copper supplements increase mortality, and folic acid (with B12) increases cancer. – Studies contradicting or limiting the claim