Everything Guide to MultiVitamins: Overview, Index, and Resource Guide

What are Multivitamins? 

Multivitamins (MVs) are dietary supplements that generally “contain a combination of vitamins and minerals, and sometimes alongside other ingredients.” 1,2 Because there is no regulated standard for what constitutes an MV, the composition of each MV varies by brand and product 3,4. For instance, the United States Department of Health and Human Services have defined MVs as “products containing at least three vitamins and minerals in amounts below the Upper Intake Level (UL) but no herbs, hormones, or drugs.” 5 On the other hand, some researchers have defined it as a “‘full-spectrum’ [product] providing all 12 vitamins plus 10 minerals.”6 Most MVs contain the following vitamins: A, B (including thiamin, riboflavin, niacin, vitamin B6, vitamin B 12, folate, and biotin), C, D, and E.7 Calcium, magnesium, zinc, selenium, iron, and potassium are minerals typically found in today’s MVs. A study of 1,246 different multivitamins’ compositions revealed the most common vitamins and minerals and their average concentrations, shown in the table below: 

Median and Average Nutrient Profiles for Multivitamin Supplements

    VitaminMedianMean
Vitamin C (mg)12060
Vitamin A (ug retinoL)13751833
Vitamin E (mg alpha-tocopherol)20.316.9
Thiamine51.5
Riboflavin (mg)5.11.7
Niacin (mg)2020
Folate (ug DFE)680300
Vitamin B-6 (mg)52.5
Vitamin B-12 (ug)1215.5
Calcium (mg)54.3180
Magnesium (mg)38.8100
Iron (mg)1.713.5
Zinc (mg)1515
Source: Murphy, Suzanne P et al. “Multivitamin-multimineral supplements’ effect on total nutrient intake.” The American journal of clinical nutrition vol. 85,1 (2007): 280S-284S. doi:10.1093/ajcn/85.1.280S 21
Median: midpoint of datapoint frequencies 
Mean: the average of datapoint frequencies
mg = milligrams
ug= micrograms

Key Facts: 

  1. The 1929 Nobel Prize in Physiology or Medicine winner Dr. Eijkman discovered that chickens who ate processed white rice (vitamin-rich outer layer stripped) would develop beriberi-like symptoms.10 When the chickens were fed regular rice (with the vitamin-rich outer layer), their health rapidly improved. 11 After Dr. Eijkman’s death, Dr. Casimir Funk discovered via isolation of substances from rice husks that it was the presence of (what is known today as) thiamine that contributed to the well-being and health of the chickens. Dr. Funk went on to call it an “amine” before putting forth the theory that there were a group of substances, “vitae anime” and later shortened to “vitamine,” that were essential for life.12
  2. In 1920, the pharmaceutical company Parke, Davis, and Company launched “Metagen,” a capsule made up of the fat-soluble vitamin A, water-soluble vitamin B, and water-soluble vitamin C. 13 However, the more formally known “first” multivitamin was the early 1920’s Mastin’s “Vitamon Tablets,” which not only contained all three of the vitamins, but also iron, calcium, and phosphorous.14
  3. Women are more likely to take multivitamins than men (34% of women vs. 28.3% of men).15,16
  4. Nearly half of American adults 18+ and 70% of people aged 71+ take multivitamins.17,18
  5. The U.S. Preventive Services Task Force, “an independent panel of experts in primary care and prevention that systematically reviews the evidence of effectiveness and develops recommendations for clinical preventive services,” reviewed 26 studies and concluded there was insufficient evidence to support any benefits of multivitamins or individual vitamins for the primary prevention of cardiovascular disease or cancer among healthy, nutrient-sufficient adults. 19,20,21
  6. Those who take MVs are oftentimes consuming more nutrients and vitamins via food and drinks compared to those who do not take MVs. 22
  7. The Food and Drug Administration (FDA) has yet to approve of any MVs on the market as they do not claim to treat, cure, diagnose, or prevent disease in any way. 23 However, since 2019, the FDA has taken a stricter approach regarding the MV industry due to them “claiming to treat Alzheimer’s disease” 24. There are smaller agency groups, such as the USP who may give their seal of approval for certain MVs that meet their criteria. 25
  8. Although commonly thought of as a form of “nutritional insurance,” 26,27 there is also the risk of too much. 28,29 Overconsumption of certain vitamins and minerals within the multivitamin such as vitamin E (leads to an increased prevalence of hemorrhagic strokes) and vitamin D (hypercalcemia) can result in harmful and even fatal conditions. 30,31 It is of utmost importance to compare the recommended dietary allowance (RDA) of each nutrient that is included within a MV. 32

Search Engine and Search Terms: 

Searched on Google, Google Scholar, and PubMed containing the following combinations of search terms from the years [2000-2023].
Inclusion Terms:

Resource Websites:

Current Uses and Scientific Review of the Literature:

Note: Before reviewing the literature, it is important to note that many peer-reviewed studies may be biased because of industry-funded research to promote product sales, and a conflict of interest is not always disclosed (see information from biologist and nutritionist Marion Nestle on sponsored research here). In this article, we have done our best not to include any industry-funded studies. As discussed in the Food as Medicine Report (on page 158, specifically), there is a need for more government funding for food as medicine initiatives. 

Multivitamins Effect on Aging Populations

Different studies show mixed results on the benefits of MVs to older patients as a specific target study group. These studies range from cognitive health (positive association between MVs and memory recall) to cardiovascular impacts (no effects). 

Blood Pressure

This meta-analysis of 12 randomized controlled studies showed there was no significant effect on MV on blood pressure (BP)33. 

Bone Health

Studies show that MVs have a positive effect on bone health (greater bone mineral density (BMD))

Cancers

Most of the below studies showed no correlation or association between multivitamin intake and incidence of any cancer or better mortality outcomes. 

Cardiovascular Disease

The majority of studies show no significant effect on CVD-caused mortality. 

Children

Most studies showed that most children already receive adequate amounts of nutrition with a balanced, healthy diet, and the use of MVs marketed for children can even contribute to an excess of micronutrients (taking more than daily allowance because they taste good, etc.) that can become toxic. 

Chronic Disease Prevention

Studies show few clear effects on chronic diseases. Higher-income country populations can usually prevent chronic diseases via a balanced and healthy diet; lower-income countries may benefit but not enough research is present to confirm. 

Cognition

No significant effect by MVs was found on cognition, except for slightly improved free memory recall. 

Multivitamin Studies on Various Sub-Populations

These were studies done on various groups of people who have high similarities. For instance, there are a few MV studies done on women, as their biological makeup and ability to produce children sets them apart from men. There is also MV research specifically looking at only higher income countries or only those living with disabilities etc. Research shows that non-ethnic minority communities (those living with disabilities, living with lower socioeconomic statuses, etc.) are more likely to use MVs. Interestingly, Whites were the most likely to use MVs when compared to all other ethnicities. Mothers who took MVs were more likely to have children that took children’s MVs. Women use MVs more than men do. 

Effective Nutritional Supplementation

One delphi consensus panel determined that MVs can be helpful in acting to specifically close the gap of deficiencies in micronutrients. This can be helpful to certain populations (young and older adults, those in a disease state, etc.) who have a temporary barrier to receiving all essential nutrients. Those who already receive nutritious diets normally would not benefit as much. 

Immunity

Most studies showed that there is reduction of infection incidences amongst those who take MVs when compared to those who did not. However, all studies state that more research is required. 

Interactions/Overconsumption

There is serious potential for overconsumption of multivitamins; this can take the form of physical indigestion buildup, negative effects on development, and more. It is very important for MV companies to market appropriately and clearly label the recommended directions on the products. 

Perceived Health/Qualitative Studies

Using MVs generally will result in positive expectations of its effect on health; people who use MVs have a more positive view of their health than they did before using MVs. 

Pregnancy

The intake of MVs have not been shown to prevent preeclampsia, which is having high blood pressure during late-stage pregnancy and can have harmful effects on the fetus. However, MVs that contain folic acid, or specifically pre-natal MVs, have a substantial net benefit on the development of neural tubes in the fetus. There are also a few studies that show a protective effect against cancer on the future child of the mother who takes MVs during pregnancy. 

Stress/Mental Health

Studies show that self-reported stress levels were decreased when taking MVs. However, because there is no clear biological mechanism between the MVs and multiple mood states, it cannot be said that this is a causal relationship. Note that stress is measured by perception. 

Videos: 

Medical Organizations on MVs: 

  • Hopkins Medicine: “The researchers concluded that multivitamins don’t reduce the risk for heart disease, cancer, cognitive decline (such as memory loss and slowed-down thinking) or an early death. They also noted that in prior studies, vitamin E and beta-carotene supplements appear to be harmful, especially at high doses.”
  • Cleveland Clinic “‘So many of my patients tell me they know their diet is not great but that I shouldn’t worry because at least they take a multivitamin,” says Taylor. “But multivitamins aren’t a surefire way to get what you need.’”
  • Harvard Health: “Most studies find no benefit from multivitamins in protecting the brain or heart. But there are potential benefits and no risks from a one daily standard multivitamin.”
  • Northwestern Medicine: “There’s no ‘magic set of pills to keep you healthy.’ Diet and exercise are key.”
  • Forbes Health: “Their purpose is to fill nutritional gaps that you may not know exist. That’s why I take one every day—just in case.”
  • Harvard Health: “Vitamins can help ward off disease and other health problems, but only in people who are severely malnourished, something that’s not true of the average American adult.”
  • Cleveland Clinic (Kids): “It’s like having an insurance policy. You don’t need it, but it’s a good idea.”
  • British Heart Foundation: “The researchers said: ‘Our study supports current professional guidelines that recommend against the routine use of multivitamin and mineral supplements for the purpose of cardiovascular disease prevention in the general population.’”
  • CNN Health: “Although supplement use remains popular with adults and children, science has not shown that they actually offer much help with health.”
  • WebMD: “Eating a balanced diet with plenty of vegetables, fruits, and whole grains should provide the vitamins your body needs. However, it’s not always possible to eat healthy meals. If that’s the case, taking supplements might help. Multivitamins are designed to fill nutritional gaps. There are different brands and formulations, and each will list the percent daily value (DV) or recommended dietary allowance (RDA) of the nutrients in one serving.” 

Books: 

Opinion Pieces: 

News Articles:

Podcasts: 

Conclusion: 

This resource guide presents a comprehensive overview of multivitamins, drawing on a variety of reliable and reputable sources, including peer-reviewed studies and expert opinions from healthcare organizations. The evidence gathered highlights the importance of understanding that there is currently less evidence than many may think there exists to back the effectiveness of a supplement often taken as “nutritional insurance.” 

References:

  1. Vitamins Come to Dinner | Science History Institute. Accessed September 16, 2023. https://sciencehistory.org/stories/magazine/vitamins-come-to-dinner/
  2. Koul PA, Ahmad SH, Ahmad F, Jan RA, Shah SU, Khan UH. Vitamin D Toxicity in Adults: A Case Series from an Area with Endemic Hypovitaminosis D. Oman Med J. 2011;26(3):201-204. doi:10.5001/omj.2011.49
  3. Fortmann SP, Burda BU, Senger CA, Lin JS, Whitlock EP. Vitamin and mineral supplements in the primary prevention of cardiovascular disease and cancer: An updated systematic evidence review for the U.S. Preventive Services Task Force. Ann Intern Med. 2013;159(12):824-834. doi:10.7326/0003-4819-159-12-201312170-00729
  4. The Nobel Prize in Physiology or Medicine 1929 – NobelPrize.org. Accessed September 16, 2023. https://www.nobelprize.org/prizes/medicine/1929/summary/
  5. Risk of excessive intake of vitamins and minerals delivered through public health interventions: objectives, results, conclusions of the meeting, and the way forward – Garcia‐Casal – 2019 – Annals of the New York Academy of Sciences – Wiley Online Library. Accessed September 16, 2023. https://nyaspubs.onlinelibrary.wiley.com/doi/full/10.1111/nyas.13975
  6. Bird JK, Murphy RA, Ciappio ED, McBurney MI. Risk of Deficiency in Multiple Concurrent Micronutrients in Children and Adults in the United States. Nutrients. 2017;9(7):655. doi:10.3390/nu9070655
  7. Huang HY, Caballero B, Chang S, et al. Multivitamin/mineral supplements and prevention of chronic disease. Evid Rep Technol Assess (Full Rep). 2006;(139):1-117 https://pubmed.ncbi.nlm.nih.gov/17764205/#:~:text=Multivitamin%2Fmineral%20supplements%20conferred%20no,multivitamin%2Fmineral%20supplements%20is%20limited.
  8. Multivitamin/mineral Supplements – Health Professional Fact Sheet. Accessed September 16, 2023. https://ods.od.nih.gov/factsheets/MVMS-HealthProfessional/
  9. Multivitamin/mineral Supplements – Consumer. Accessed September 16, 2023. https://ods.od.nih.gov/factsheets/MVMS-Consumer/
  10. Multivitamin-multimineral supplements’ effect on total nutrient intake – PubMed. Accessed September 16, 2023. https://pubmed.ncbi.nlm.nih.gov/17209210/
  11. Is There Really Any Benefit to Multivitamins? | Johns Hopkins Medicine. Accessed September 16, 2023. https://www.hopkinsmedicine.org/health/wellness-and-prevention/is-there-really-any-benefit-to-multivitamins
  12. Home page | United States Preventive Services Taskforce. Accessed September 16, 2023. https://www.uspreventiveservicestaskforce.org/uspstf/
  13. Front page | Quality Supplements. Accessed September 16, 2023. http://www.quality-supplements.org/
  14. FDA takes action against 17 companies for illegally selling products claiming to treat Alzheimer’s disease | FDA. Accessed September 16, 2023. https://www.fda.gov/news-events/press-announcements/fda-takes-action-against-17-companies-illegally-selling-products-claiming-treat-alzheimers-disease
  15. Dietary Supplement Use Differs by Socioeconomic and Health-Related Characteristics among U.S. Adults, NHANES 20112014 – PubMed. Accessed September 16, 2023. https://pubmed.ncbi.nlm.nih.gov/30126136/
  16. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. National Academies Press; 2006. doi:10.17226/11537
  17. Kamiński M, Kręgielska-Narożna M, Bogdański P. Determination of the Popularity of Dietary Supplements Using Google Search Rankings. Nutrients. 2020;12(4):908. doi:10.3390/nu12040908
  18. Christiaan Eijkman (1856–1930) | Journal of Neurology. Accessed September 16, 2023. https://link.springer.com/article/10.1007/s00415-018-9162-7
  19. Rosenberg IH. Challenges and opportunities in the translation of the science of vitamins. Am J Clin Nutr. 2007;85(1):325S-7S. doi:10.1093/ajcn/85.1.325S
  20. Samuel L, Ethan D, Basch C, Dunne S, Quinn C. An analysis of nutrient facts labels of pediatric multi-vitamin and mineral supplements: Is there a risk of overexposure? Nutr Health. Published online May 11, 2022:2601060221100926. doi:10.1177/02601060221100926
  21. Murphy, Suzanne P et al. “Multivitamin-multimineral supplements’ effect on total nutrient intake.” The American journal of clinical nutrition vol. 85,1 (2007): 280S-284S. doi:10.1093/ajcn/85.1.280S 
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