Do you need a multivitamin?

Multivitamins are very useful if you have a poor diet, but they lose much of their benefit if you have a good diet. Many people with good diets take multivitamins unnecessarily. Just supplement the nutrients you need instead.

Written by and verified by the Research Team. Last updated on May 1, 2018.

What is a multivitamin?

'Multivitamin' is a blanket term to refer to any supplement, usually in a pill or tablet form, that provides essential vitamins or minerals. Not all nutrients are present in each multivitamin, as iron is sometimes omitted. The majority of essential vitamins and minerals are in most multivitamins, in varying dosages.

They are normally used to 'cover all the bases' when it comes to supplementation of vitamins and minerals.

Who needs a multivitamin?

A multivitamin tends to be a good idea if:

  • You are at risk for several nutrient deficiencies and your diet cannot otherwise be modified

  • The multivitamin provides adequate dosages to cover the deficiency risk

  • The multivitamin is a better purchasing option than the nutrients by themselves

Theoretically, multivitamins would provide more overall benefit to people with a lower income, who are financially unable to buy a wide variety of foods. Ironically, this group is the least likely to consume multivitamins.[1]

Multivitamins can also be recommended to pregnant women, due to their increased need for folic acid, which is important for fetal development,[2] and to reduce complications associated with pregnancy in general.[3][4] Elderly people can also benefit from multivitamins, as they tend to be at a higher risk for nutrient deficiencies, such as vitamin B12.[5]

What if I only have a few nutrient deficiencies?

Many nutrients can be supplemented individually, like Vitamin D or Magnesium.

If you suspect that you are at risk for a nutrient deficiency, you can omit the multivitamin from your daily routine and just supplement the nutrients your diet lacks.

Healthy or dangerous?

Neither, really.

There is insufficient evidence to suggest a multivitamin is associated with less risk of cancer and disease,[6] and this holds true when investigating the most popular compounds in multivitamins, the anti-oxidants.[7][8][9]

Some studies note higher mortality associated with multivitamin use, but the relative risk ratios tend to not surpass 2.00 (in which a number greater than 1, or no difference, suggests a stronger possible relation). This is not strong evidence for causation.[10] This weak association is also found when cherry-picking some other studies,[11] but strong relationships between multivitamins and harm have not been found.

Some studies that investigated both benefit and harm, report neither.[12][13]

Although nutrients in multivitamins may confer benefits when used for a specific purpose, (as some studies note high variability, suggesting some people benefit and others do not)[14][15][16] the idea of taking a pill that contains all of the vitamins and minerals to better one's health does not appear to be supported by the literature. However, it does not appear to be significantly harmful either.


  1. Shelton RC, et al. Multivitamin use among multi-ethnic, low-income adults . Cancer Causes Control. (2009)
  2. Stampfer M. Toward optimal health: Meir Stampfer, M.D., DR.P.H., discusses multivitamin and mineral supplementation for women . J Womens Health (Larchmt). (2007)
  3. Catov JM, et al. Association of periconceptional multivitamin use and risk of preterm or small-for-gestational-age births . Am J Epidemiol. (2007)
  4. Vahratian A, et al. Multivitamin use and the risk of preterm birth . Am J Epidemiol. (2004)
  5. Park S, Johnson M, Fischer JG. Vitamin and mineral supplements: barriers and challenges for older adults . J Nutr Elder. (2008)
  6. Huang HY, et al. The efficacy and safety of multivitamin and mineral supplement use to prevent cancer and chronic disease in adults: a systematic review for a National Institutes of Health state-of-the-science conference . Ann Intern Med. (2006)
  7. Lin J, et al. Vitamins C and E and beta carotene supplementation and cancer risk: a randomized controlled trial . J Natl Cancer Inst. (2009)
  8. Lee IM, et al. Beta-carotene supplementation and incidence of cancer and cardiovascular disease: the Women's Health Study . J Natl Cancer Inst. (1999)
  9. Lee IM, et al. Vitamin E in the primary prevention of cardiovascular disease and cancer: the Women's Health Study: a randomized controlled trial . JAMA. (2005)
  10. Mursu J, et al. Dietary supplements and mortality rate in older women: the Iowa Women's Health Study . Arch Intern Med. (2011)
  11. Stevens VL, et al. Use of multivitamins and prostate cancer mortality in a large cohort of US men . Cancer Causes Control. (2005)
  12. Hennekens CH, et al. Lack of effect of long-term supplementation with beta carotene on the incidence of malignant neoplasms and cardiovascular disease . N Engl J Med. (1996)
  13. Jacobs EJ, et al. Vitamin C, vitamin E, and multivitamin supplement use and stomach cancer mortality in the Cancer Prevention Study II cohort . Cancer Epidemiol Biomarkers Prev. (2002)
  14. Stratton J, Godwin M. The effect of supplemental vitamins and minerals on the development of prostate cancer: a systematic review and meta-analysis . Fam Pract. (2011)
  15. Kirsh VA, et al. Supplemental and dietary vitamin E, beta-carotene, and vitamin C intakes and prostate cancer risk . J Natl Cancer Inst. (2006)
  16. Huang HY, et al. Multivitamin/mineral supplements and prevention of chronic disease . Evid Rep Technol Assess (Full Rep). (2006)