Do we really need vitamins?

show/hide words to know

Antioxidant: a molecule that can prevent the damaging effects of stress in the body......more

Contaminant: a material that doesn't belong in a product.

Free radical: a molecule that has an unpaired electron, making the molecule quick to react or combine with other molecules....more

Regulate: to control the levels of something, such as body temperature.

Supplement: a product made to add something extra to a diet.

Verify: to check if something is true.

“Helps clear toxins from your body*!” “Provides antioxidant protection against free radicals*!” “Formulated for sports players*!” Many supplements claim to be helpful products that protect or enhance your health. However, these claims come with a little asterisk (*) and a statement that the claims have not been verified. But if a product has made it to the shelf, they must at least be safe, right?


Vitamins and supplements don't have to be tested thoroughly before they can be sold.

This is the case for medications. These drugs are highly regulated, with major requirements for creating, labeling, and selling drugs. These steps all require lengthy clinical and laboratory testing. Medications must be found to be effective and safe before they can be sold. However, this is not true for vitamins.

Currently, there are no standards or regulations for multivitamins, such as what nutrients they must contain and in what amounts. Manufacturers determine the types and amounts of vitamins, minerals, and other ingredients that multivitamins contain. Because vitamin supplements are not treated as drugs, the Food and Drug Administration (FDA) is not authorized to judge how effective or safe a supplement is before it can be sold.

Under current law, supplements are assumed safe until shown otherwise. They are not removed from shelves until after injuries to users occur. Once supplements are for sale, any serious events reported by customers or health care professionals must be reported to the FDA. In general, the FDA’s role with a supplement begins after the product is for sale, so it takes significant user harm to start investigations of products that may be unsafe. This can leave a lot of room for bad products to be sold.


Supplements need to be judged by a third party for you to know if they are high quality. Image by Clint Penick.

Most once-a-day multivitamins are not always made consistently, but many contain all or most of the recognized vitamins and minerals. Generally, they provide levels close to the amounts recommended for humans to get on a daily basis. There are formulations (like recipes) for children, adults, men, women, pregnant women, and senior citizens. Each formulation typically provides different amounts of the same vitamins and minerals based on the needs of these populations. Some products contain a higher concentration of vitamins and minerals than what is recommended or might include other nutritional and herbal ingredients.

Unfortunately, supplements can contain cheap materials that have no benefit and they may include contaminants. Manufacturers may not even list ingredients on the product. We might have no way of knowing what is used unless it is third-party verified. So how can you find quality vitamin supplements?

 Additional images via Wikimedia Commons. Image of women playing soccer by Ad.jordan.

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Bibliographic details:

  • Article: Are Vitamins Safe?
  • Author(s): Danielle Penick
  • Publisher: Arizona State University School of Life Sciences Ask A Biologist
  • Site name: ASU - Ask A Biologist
  • Date published: May 7, 2018
  • Date accessed: January 27, 2023
  • Link:

APA Style

Danielle Penick. (2018, May 07). Are Vitamins Safe?. ASU - Ask A Biologist. Retrieved January 27, 2023 from

American Psychological Association. For more info, see

Chicago Manual of Style

Danielle Penick. "Are Vitamins Safe?". ASU - Ask A Biologist. 07 May, 2018.

MLA 2017 Style

Danielle Penick. "Are Vitamins Safe?". ASU - Ask A Biologist. 07 May 2018. ASU - Ask A Biologist, Web. 27 Jan 2023.

Modern Language Association, 7th Ed. For more info, see
women playing soccer
Some vitamins are made especially for athletes. But do we really know if the vitamins are working the way they are supposed to?

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