Do Multivitamins Work?

Author:
Julian Ghadially, MPH
April 25, 2023

Summary

  • Evidence suggests multivitamins have both good and bad ingredients
  • 90% of top selling multivitamins include 3 or more ingredients linked to cancer
  • 60% of ingredients in top selling multivitamins are unnecessary
  • Overall, multivitamins may offer some small cancer reduction, but effects would be stronger by focusing on just the good ingredients

Multivitamins contain dozens of essential ingredients that are necessary for survival. They have been popular since the 1940s as a safeguard against poor diets.  

We took the top 10 adult multivitamins by sales on Amazon (as of March 2023) and evaluated each ingredient for risk and necessity.

Good ingredients

The good news is that multivitamins do contain some good ingredients - vitamin D, magnesium, vitamin C, and calcium all have benefits as shown in our full supplements review. They also can prevent vitamin deficiencies if your diet is severely lacking a given nutrient or if you have an issue in absorbing nutrients.

Bad ingredients

However, 90% of top selling multivitamins include 3 or more ingredients linked to possible cancer risks (See Table 1 below). Even some vitamins that are beneficial when derived from food have been linked to cancer risks when taken in supplement form. The US Preventive Services Task Force found that across 4 randomized controlled trials, cancer odds increased by 20% when vitamin A or beta-carotene supplementation was used.1 (Note that vitamin A is present in all 10 best-selling multivitamins). Similarly, the large SELECT trial and a mortality review both found statistically significant increases in prostate cancer rates or mortality with vitamin E, another common multivitamin ingredient.2,5,6 Additionally, multivitamins also include all the filler additives like BHT, silicon dioxide, gums, etc., which could contain risks.

Suboptimal results

Overall, the good ingredients in multivitamins seem to balance out the bad ingredients for net neutral results. In the same USPSTF meta-analysis, the overall cancer impact of multivitamins ranged between no impact to a small impact.1 Additionally, mortality and cardiovascular health were not improved. Thus, why not omit the risky and unnecessary ingredients and focus on letting the good ingredients do their job?

Focusing on the good, omitting the bad

Our approach to supplementation is to focus on the good ingredients. Our assessment can identify the best ingredients for you, based on research from 300+ studies. We package only the effective ingredients and omit anything unnecessary.

Table 1: Ingredients in The Top 10 Multivitamins on Amazon

Note: Ingredients with no entries in the "Unnecessary or Risky" column are neither unnecessary nor risky, as determined by an evidence of benefit or greater than 5% of the population lacking recommended levels. The top 10 adult multivitamins on Amazon at the time of this publication were: Vitafusion Women's Multivitamin, OLLY Women's Multivitamin Gummy, One-a-Day Men's Multivitamin, Vitafusion Adult Gummy Vitamins for Men, One-a-Day Women's Complete Daily Multivitamin, Sugarbear Hair Vitamin Gummies for Normal Hair & Nails Growth,  Centrum Multivitamin for Men 50 Plus, Garden of Life Multivitamin for Women, Solimo Adult Multivitamin, Centrum Silver Multivitamin for Women 50 Plus

References

  1. O’Connor EA, Evans CV, Ivlev I, et al. Vitamin, Mineral, and Multivitamin Supplementation for the Primary Prevention of Cardiovascular Disease and Cancer: A Systematic Evidence Review for the U.S. Preventive Services Task Force. Rockville (MD): Agency for Healthcare Research and Quality (US); 2021 Jun. (Evidence Synthesis, No. 209.) Available from: https://www.ncbi.nlm.nih.gov/books/NBK581642/
  2. Klein EA, Thompson IM Jr, Tangen CM, Crowley JJ, Lucia MS, Goodman PJ, Minasian LM, Ford LG, Parnes HL, Gaziano JM, Karp DD, Lieber MM, Walther PJ, Klotz L, Parsons JK, Chin JL, Darke AK, Lippman SM, Goodman GE, Meyskens FL Jr, Baker LH. Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA. 2011 Oct 12;306(14):1549-56. doi: 10.1001/jama.2011.1437. PMID: 21990298; PMCID: PMC4169010.
  3. U.S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Food Surveys Research Group (Beltsville, MD) and U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Health Statistics (Hyattsville, MD). What We Eat in America, NHANES 2015-2018 Type of File: Usual Intake Data Tables (2021, January). Available from: https://www.ars.usda.gov/northeast-area/beltsville-md-bhnrc/beltsville-human-nutrition-research-center/food-surveys-research-group/docs/wweia-usual-intake-data-tables/ [accessed 04/12/23].
  4. U.S. Department of Health and Human Services. (n.d.). Dietary supplement fact sheets. NIH Office of Dietary Supplements. Retrieved April 12, 2023, from https://ods.od.nih.gov/factsheets/list-all/
  5. Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. Mortality in Randomized Trials of Antioxidant Supplements for Primary and Secondary Prevention: Systematic Review and Meta-analysis. JAMA. 2007;297(8):842–857. doi:10.1001/jama.297.8.842
  6. Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database Syst Rev. 2012 Mar 14;2012(3):CD007176. doi: 10.1002/14651858.CD007176.pub2. PMID: 22419320; PMCID: PMC8407395.
Savvy.Care provides research-backed vitamin plans. We do not profit off of any of the products we recommend, opting instead for a fixed membership model. Learn more at our about page.
HomeAboutGet RecommendationContact Us