Multivitamin supplementation benefits and risks
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Multivitamin Supplementation: Benefits and Risks Overview
Multivitamin supplements are widely used, with many adults taking them for general health, to fill dietary gaps, and in hopes of preventing major diseases like cardiovascular disease (CVD) and cancer. However, research shows mixed results regarding their actual benefits and potential risks.
Cardiovascular Disease and Multivitamin Supplementation
Modest or No Reduction in Cardiovascular Risk
Large studies and meta-analyses generally find that multivitamin supplementation does not significantly reduce the risk of cardiovascular disease or related mortality in the general population. Most research shows no clear association between multivitamin use and lower rates of CVD events, CVD mortality, coronary heart disease, or stroke, with only some studies suggesting a very modest reduction in certain subgroups, such as younger adults and smokers, or a slight reduction in myocardial infarction risk in both men and women 1236+2 MORE.
Cancer Prevention and Multivitamin Use
Limited Evidence for Cancer Prevention
The evidence for multivitamin use in cancer prevention is limited. Some studies report a small reduction in overall cancer incidence and specifically colon cancer, but these benefits are minor and not consistent across all research. In some cases, higher multivitamin use was linked to slightly increased risks of certain cancers, such as prostate, lung, leukemia in men, and oropharyngeal cancer in women 1278.
Mortality and Multivitamin Supplementation
No Clear Mortality Benefit
Most large-scale studies and meta-analyses find that multivitamin supplementation does not lower overall mortality risk. Some research even suggests a slight increase in mortality among multivitamin users in the early years of follow-up, though this effect is small and may be influenced by other factors 457.
Birth Defects and Multivitamin Use
Benefits for Birth Defect Prevention
There is strong evidence that multivitamin supplements containing folic acid reduce the risk of neural tube defects in newborns. Some data also suggest that periconceptional multivitamin use may lower the risk of other birth defects, such as limb reduction and urinary tract defects, though the specific nutrients responsible are not always clear .
Potential Risks and Harms of Multivitamin Supplementation
Specific Supplement Risks
While most multivitamin supplements are considered safe for the general population, certain vitamins and minerals can pose risks when taken in excess or by specific groups. For example, beta carotene supplementation is associated with an increased risk of lung cancer and cardiovascular mortality, especially in people at high risk for lung cancer. Other supplements, such as vitamin A, vitamin E, vitamin C, and calcium, have been linked to increased risks of hip fracture, hemorrhagic stroke, and kidney stones in some studies 12.
Conclusion
Overall, the current evidence suggests that multivitamin supplementation provides little or no benefit in preventing cardiovascular disease, cancer, or reducing mortality for most healthy adults. There may be a small benefit for certain cancers and birth defects, particularly with folic acid-containing supplements. However, some supplements can increase health risks, especially when used in high doses or by specific populations. For most people, a balanced diet remains the best approach to meeting nutritional needs and reducing disease risk 1234+6 MORE.
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