Multivitamin
A multivitamin is a preparation intended to serve as a
In healthy people, most scientific evidence indicates that multivitamin supplements do not prevent cancer, heart disease, or other ailments, and regular supplementation is not necessary.[2][3][4][5][6][7][8] However, specific groups of people may benefit from multivitamin supplements, for example, people with poor nutrition or those at high risk of macular degeneration.[3][9]
There is no standardized scientific definition for multivitamin.[10] In the United States, a multivitamin/mineral supplement is defined as a supplement containing three or more vitamins and minerals that does not include herbs, hormones, or drugs, where each vitamin and mineral is included at a dose below the tolerable upper intake level as determined by the Food and Drug Board, and does not present a risk of adverse health effects.[11]
Products and components
Many multivitamin formulas contain
Some nutrients, such as calcium and magnesium, are rarely included at 100% of the recommended allowance because the pill would become too large in size. Most multivitamins come in capsule form; tablets, powders, liquids, and injectable formulations also exist. In the United States, the
Uses
For certain people, particularly for older people, supplementing the diet with additional vitamins and minerals can have health impacts; however, the majority will not benefit.[13] People with dietary imbalances may include those on restrictive diets and those who cannot or will not eat a nutritious diet. Pregnant women and elderly adults have different nutritional needs compared to other adults, and a multivitamin may be indicated by a physician. Generally, medical advice is to avoid multivitamins during pregnancy, particularly those containing vitamin A, unless they are recommended by a health care professional. However, the NHS recommends 10μg of Vitamin D per day throughout the pregnancy and while breastfeeding, and 400μg of folic acid during the first trimester (first 12 weeks of pregnancy).[14] Some women may need to take iron, vitamin C, or calcium supplements during pregnancy, but only on the advice of a doctor.
In the 1999–2000 National Health and Nutrition Examination Survey, 52% of adults in the United States reported taking at least one dietary supplement in the last month and 35% reported regular use of multivitamin-multimineral supplements. Women versus men, older adults versus younger adults, non-Hispanic whites versus non-Hispanic blacks, and those with higher education levels versus lower education levels (among other categories) were more likely to take multivitamins. Individuals who use dietary supplements (including multivitamins) generally report higher dietary nutrient intakes and healthier diets. Additionally, adults with a history of prostate and breast cancers were more likely to use dietary and multivitamin supplements.[15]
Precautions
The amounts of each vitamin type in multivitamin formulations are generally adapted to correlate with what is believed to result in optimal health effects in large population groups. However, these standard amounts may not correlate with what is optimal in certain subpopulations, such as in children, pregnant women and people with certain medical conditions and medication.
The health benefit of vitamins generally follows a biphasic
In particular, pregnant women should consult their doctors before taking any multivitamins. For example, either an excess or deficiency of vitamin A can cause birth defects.[19]
Long-term use of
Severe vitamin and mineral deficiencies require medical treatment and can be very difficult to treat with common over-the-counter multivitamins. In such situations, special vitamin or mineral forms with much higher potencies are available, either as individual components or as specialized formulations.
Multivitamins in large quantities may pose a risk of an acute
As noted in dietary guidelines from Harvard School of Public Health in 2008, multivitamins should not replace healthy eating or make up for unhealthy eating.[24][failed verification] In 2015, the U.S. Preventive Services Task Force analyzed studies that included data for about 450,000 people. The analysis found no clear evidence that multivitamins prevent cancer or heart disease, helped people live longer, or "made them healthier in any way."[25]
Research
Provided that precautions are taken (such as adjusting the vitamin amounts to what is believed to be appropriate for children, pregnant women or people with certain medical conditions), multivitamin intake is generally safe, but research is still ongoing with regard to what health effects multivitamins have.
Evidence of health effects of multivitamins comes largely from
Cohort studies
In February 2009, a study conducted in 161,808
A cohort study that received widespread media attention
Using the same PHS-II study, researchers concluded that taking a daily multivitamin did not have any effect in reducing
Systematic reviews and meta-analyses
One major meta-analysis published in 2011, including previous cohort and case-control studies, concluded that multivitamin use was not significantly associated with the risk of breast cancer. It noted that one Swedish cohort study has indicated such an effect, but with all studies taken together, the association was not statistically significant.[29] A 2012 meta-analysis of ten randomized, placebo-controlled trials published in the Journal of Alzheimer's Disease found that a daily multivitamin may improve immediate recall memory, but did not affect any other measure of cognitive function.[37]
Another meta-analysis, published in 2013, found that multivitamin-multimineral treatment "has no effect on mortality risk",[38] and a 2013 systematic review found that multivitamin supplementation did not increase mortality and might slightly decrease it.[39] A 2014 meta-analysis reported that there was "sufficient evidence to support the role of dietary multivitamin/mineral supplements for the decreasing the risk of age-related cataracts."[40] A 2015 meta-analysis argued that the positive result regarding the effect of vitamins on cancer incidence found in Physicians' Health Study II (discussed above) should not be overlooked despite the neutral results found in other studies.
Looking at 2012 data, a study published in 2018 presented meta-analyses on cardiovascular disease outcomes and all-cause mortality. It found that "conclusive evidence for the benefit of any supplement across all dietary backgrounds (including deficiency and sufficiency) was not demonstrated; therefore, any benefits seen must be balanced against possible risks." The study dismissed the benefits of routinely taking supplements of vitamins C and D, beta-carotene, calcium, and selenium. Results indicated taking niacin may actually be harmful.[4][5]
In July 2019, another meta-analysis of 24 interventions in 277 trials was conducted and published in
Expert bodies
A 2006 report by the U.S. Agency for Healthcare Research and Quality concluded that "regular supplementation with a single nutrient or a mixture of nutrients for years has no significant benefits in the primary prevention of cancer, cardiovascular disease, cataract, age-related macular degeneration or cognitive decline."[9] However, the report noted that multivitamins have beneficial effects for certain sub-populations, such as people with poor nutritional status, that vitamin D and calcium can help prevent fractures in older people, and that zinc and antioxidants can help prevent age-related macular degeneration in high-risk individuals.[9] A 2017 Cochrane Systematic Review found that multivitamins including vitamin E or beta carotene will not delay the onset of macular degeneration or prevent the disease,[44] however, some people with macular degeneration may benefit from multivitamin supplementation as there is evidence that it may delay the progression of the disease.[45] Including lutein and zeaxanthin supplements in with a multivitamin does not improve progression of macular degeneration.[45] The need for high-quality studies looking at the safety of taking multivitamins has been highlighted.[45]
According to the
Regulations
This section needs expansion. You can help by adding to it. (March 2009) |
United States
The first person to formulate vitamins in the US was Dr. Forrest C. Shaklee.[47] Shaklee introduced a product he dubbed "Shaklee's Vitalized Minerals" in 1915, which he sold until adopting the now ubiquitous term "vitamin" in 1929.[48]
Because of their categorization as a dietary supplement by the Food and Drug Administration (FDA), most multivitamins sold in the U.S. are not required to undergo the testing procedures typical of pharmaceutical drugs. However, some multivitamins contain very high doses of one or several vitamins or minerals, or are specifically intended to treat, cure, or prevent disease, and therefore require a prescription or medicinal license in the U.S. Since such drugs contain no new substances, they do not require the same testing as would be required by a New Drug Application, but were allowed on the market as drugs due to the Drug Efficacy Study Implementation program.[49]
Australia
Vitamins are classed as low-risk medications by the Therapeutic Goods Administration (TGA), and are therefore not assessed for efficacy, unlike most medicines sold in Australia. They require that the product is safe and that claims of efficacy can only be made in regards to minor ailments. No claims can be made about serious conditions. The TGA does not examine the contents of the product and whether it is what the label says it is, but they claim to carry out "targeted and random surveillance of products on the market."[50] They encourage people to report any unsafe products to them.
The TGA, however, has been criticized, by people such as
See also
- Dietary supplement
- Essential nutrient
- Food fortification
- Megavitamin therapy
- Prenatal vitamins
References
- ^ "Guidelines for Vitamin and Mineral Food Supplements" (PDF). 2005. CAC/GL 55 - 2005. Archived (PDF) from the original on 2012-04-25. Retrieved 2019-10-06.
- ^ PMID 22419320.
- ^ a b c "Dietary Supplement Fact Sheet: Multivitamin/mineral Supplements". Office of Dietary Supplements, National Institutes of Health. Archived from the original on February 18, 2012. Retrieved March 2, 2012.
- ^ a b Litman RS (June 5, 2018). "New study on supplemental vitamins proves they're useless and a waste of money". Philly.com. Archived from the original on July 9, 2018. Retrieved July 9, 2018.
- ^ PMID 29852980.
- ^ S2CID 19463847.
- ^ PMID 31284304.
- ^ "An Untold Truth of Vitamins". Healthyfiy. Archived from the original on 20 October 2020. Retrieved 15 October 2020.
- ^ PMID 17764205. Archived from the original(PDF) on 2008-09-16.
- PMID 17209208.
- ^ National Institutes of Health State-of-the-Science Panel. National Institutes of Health State-of-the-Science Conference Statement: multivitamin/mineral supplements and chronic disease prevention" Am J Clin Nutr 2007;85:257S-64S
- ^ "How to Choose a Multivitamin Supplement". WebMD. Archived from the original on 22 July 2016. Retrieved 20 July 2016.
- ^ Dietary supplements: Using vitamin and mineral supplements wisely Archived 2013-10-12 at the Wayback Machine, Mayo Clinic
- ^ National Health Service. "Vitamins and nutrition in pregnancy". NHS Choices. NHS. Archived from the original on 10 January 2014. Retrieved 10 January 2014.
- PMID 17209209.
- ^ Combs GF (1998). The vitamins: Fundamental aspects in nutrition and health. San Diego, CA: Academic Press.
- ^ "Vitamin and Mineral Recommendations". Council for Responsible Nutrition. Archived from the original on 2012-10-31. Retrieved 2017-10-01.. Retrieved 2011-03-30.
- ^ "Vitamin C (Ascorbic acid)". MedlinePlus. U.S. National Library of Medicine. 2010. Archived from the original on 5 October 2015. Retrieved 23 March 2018.
- PMID 10331090.
- ^ "Beta-Carotene". MedlinePlus. U.S. National Library of Medicine. 1 November 2017. Archived from the original on 26 December 2016. Retrieved 6 October 2019.
- PMID 7837315.
- S2CID 19636488.
- PMID 11820922.
- ^ Harvard School of Public Health (2008). Food pyramids: What should you really eat?. Retrieved from http://www.hsph.harvard.edu/nutritionsource Archived 2011-04-20 at the Wayback Machine
- ^ "Why You Don't Need A Multivitamin – Consumer Reports". Archived from the original on 2015-09-10. Retrieved 2015-09-10.
- (PDF) from the original on 2019-12-17. Retrieved 2019-07-10.
- PMID 8179050.
- ^ PMID 19204221.
- ^ S2CID 22445157.
- PMID 20805450.
- PMID 21343248.
- New York Times. Archivedfrom the original on October 18, 2012. Retrieved October 17, 2012.
- ^ Winslow, Ron (18 October 2012). "Multivitamin Cuts Cancer Risk, Large Study Finds". The Wall Street Journal. Archived from the original on 22 December 2015. Retrieved 13 December 2012.
- PMID 23162860.
- ^ PMID 23150011.
- PMID 23117775.
- S2CID 19767652.
- PMID 23255568.
- S2CID 24230868.
- PMID 24590236.
- ^ "Save Your Money: Vast Majority Of Dietary Supplements Don't Improve Heart Health or Put Off Death". Johns Hopkins Medicine. 2019-07-16. Archived from the original on 2019-07-25. Retrieved 25 July 2019.
- ^ Haridy, Rich (2019-07-22). "Massive meta-study finds most vitamin supplements have no effect on lifespan or heart health". New Atlas. Archived from the original on 2019-07-25. Retrieved 25 July 2019.
- S2CID 51615818.
- PMID 28756617.
- ^ PMID 28756618.
- ^ "Vitamins". harvard.edu. 18 September 2012. Archived from the original on 23 March 2018. Retrieved 23 March 2018.
- ^ Longden T (27 January 2008). "Famous Iowans: Forrest Shaklee". The Des Moines Register.[permanent dead link]
- ISBN 978-0-06-015005-1.
- Fed. Reg.6843 (Apr. 9, 1971).
- ^ "Watched Vitamania? Here's how the TGA regulates vitamins in Australia". Therapeutic Goods Administration. 2018-08-14. Archived from the original on 2019-01-19. Retrieved 17 January 2019.
- Sydney Morning Herald. 2018-02-08. Archivedfrom the original on 2019-01-19. Retrieved 17 January 2019.
External links
- Dietary Supplement Fact Sheet: Multivitamin/mineral Supplements, from the U.S. National Institutes of Health
- Safe upper levels for vitamins and minerals – Report of the UK Food Standards Agency Expert Group on Vitamins and Minerals