What are multivitamins used for
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The Uses of Multivitamins: A Comprehensive Overview
Introduction to Multivitamins
Multivitamins are among the most commonly used dietary supplements globally, particularly in the United States, where a significant portion of the population reports regular use . These supplements typically contain a combination of vitamins and minerals, often at levels close to the recommended dietary allowances, and are used to ensure adequate nutrient intake and to prevent or mitigate various health conditions.
Multivitamins for Chronic Disease Prevention
Cancer and Cardiovascular Disease
Multivitamins are frequently used with the aim of preventing chronic diseases, including cancer and cardiovascular diseases. However, the evidence supporting their efficacy in this regard is mixed. A systematic review for the National Institutes of Health found that while multivitamins are widely used for primary prevention of chronic diseases, the evidence from randomized controlled trials does not strongly support their effectiveness in preventing cancer or cardiovascular diseases. Similarly, a meta-analysis concluded that multivitamin-multimineral supplementation does not significantly affect all-cause mortality, cardiovascular mortality, or cancer mortality.
Cognitive Function
The impact of multivitamins on cognitive performance has also been studied extensively. A systematic review and meta-analysis found that multivitamins can improve immediate free recall memory but do not significantly affect other cognitive domains such as delayed recall memory or verbal fluency. This suggests that while multivitamins may have some benefits for specific aspects of cognitive function, their overall impact on cognitive health remains uncertain.
Multivitamins for Specific Populations
Pregnant Women
Multivitamins, often combined with iron and folic acid, are recommended for pregnant women to improve birth outcomes and reduce the risk of low birth weight and miscarriage . A systematic review and meta-analysis focusing on high-income countries found that multivitamin use during pregnancy is associated with a reduced risk of small for gestational age infants and certain congenital anomalies, although the quality of evidence was generally low.
Elderly Population
In the elderly, multivitamins are used to address potential nutrient deficiencies that can arise due to age-related changes in diet and nutrient absorption. Studies have shown that long-term use of multivitamins in the elderly is generally safe and does not result in significant adverse effects .
Safety and Adverse Effects
The safety of long-term multivitamin use has been a subject of research, with findings indicating that multivitamins are generally safe when used within the recommended dietary intake levels. Minor adverse effects, such as gastrointestinal symptoms, have been reported, but no significant differences in adverse effects were found between multivitamin and placebo groups in various studies . Additionally, a meta-analysis found no evidence that multivitamin use increases mortality risk.
Psychological Wellbeing and Inflammation
Multivitamins are also used to support mental health, particularly during periods of stress. An 8-week randomized controlled trial found that while multivitamin supplementation did not significantly improve psychological state, it did have a positive impact on certain pro-inflammatory cytokine profiles in women experiencing psychological distress.
Conclusion
Multivitamins are widely used for various health benefits, including the prevention of chronic diseases, support of cognitive function, and improvement of birth outcomes in pregnant women. While they are generally safe for long-term use, their efficacy in preventing major health conditions such as cancer and cardiovascular disease remains inconclusive. Further research, particularly well-designed randomized controlled trials, is needed to fully understand the benefits and limitations of multivitamin supplementation.
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