Main Research Findings
Cardiovascular Disease
- PHS II Study: 11-year tracking of 14,641 male doctors, no statistically significant difference between multivitamin group and placebo group in myocardial infarction (4.2% vs 4.1%) and stroke (3.9% vs 4.1%) incidence
- USPSTF 2022 Report: Through meta-analysis of 84 clinical trials, routine supplementation of vitamin E, vitamin D, and calcium have no obvious benefit in preventing cardiovascular disease mortality
- Risk warnings:
- Beta-carotene: 28% increased lung cancer risk in smokers
- Vitamin E (>400IU/day): 13% increased hemorrhagic stroke risk
Cancer
- PHS II: Multivitamin takers had approximately 8% reduction in overall cancer incidence, but similar effect not observed in women group
- ATBC Study: Daily supplementation of 20mg beta-carotene actually increased lung cancer risk by 18% in smokers
- 2022 Nature sub-journal: Excessive vitamin B3 may promote tumor metastasis through NAD+ metabolism
Diabetes and Metabolic Diseases
Currently no sufficient evidence shows multivitamins can prevent diabetes or hypertension. The key to controlling metabolic diseases remains diet structure and lifestyle.
Cognitive Aging
- Contradictory evidence: Multiple large-scale RCTs (like PREADVISE, SELECT) show routine multivitamin intake cannot effectively prevent memory decline or dementia
- New finding: COSMOS-Mind trial (2022, 2,262 participants over 65) found daily multivitamin intake can slow cognitive decline by approximately 60%, equivalent to cognitive age 1.8 years younger
All-Cause Mortality
Multiple large-scale prospective studies and meta-analyses show taking multivitamins has no statistically significant association with all-cause mortality.
Conclusion
| Population Type | Supplementation Recommendations |
|---|---|
| General healthy population | Not recommended for long-term multivitamin use for chronic disease prevention |
| Pregnant women | Folate supplementation can reduce fetal neural tube defects by 50-70% |
| Elderly | Vitamin D and calcium supplementation can reduce osteoporotic fracture risk by 15-30% |
| Nutrient-deficient populations | Supplement nutrients lacking |
Core perspective: For healthy people, vitamin supplement research is sufficient; current evidence does not support their use for chronic disease prevention. Healthy lifestyle (balanced diet, regular exercise, controlling risk factors) is the core of chronic disease prevention, cannot be replaced by supplements.