Dietary Supplement Safety, Regulation and Standardization

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Dietary supplements are regulated to some extent but not as strictly as medications. In the United States, for example, the Food and Drug Administration (FDA) doesn't require proof that dietary supplements are safe or effective before they are sold. Some products are advertised to have health benefits but have no clinical trials demonstrating safety or effectiveness.

But supplement manufacturers must follow a few do's and don'ts when it comes to labeling and making certain claims on their products.

The label on a dietary supplement bottle may state the supplement addresses a nutrient deficiency, supports health, or may have an effect on some function or structure of the body -- if these claims are supported by research. Each type of claim has a specific meaning:

  • A nutrient content claim states the approximate amount of the dietary substances in the product.
  • Health claims indicate a relationship between consuming the dietary substance and changing disease risk if there is sufficient evidence. These claims are regulated by the FDA.
  • Structure or function claims describe how the dietary substances may affect the body. These claims are not regulated by the FDA, so it is up to each supplement manufacturer to be truthful and accurate with these claims.

Although dietary supplements don't have to prove safety or effectiveness before marketing, the FDA may determine that a dietary supplement is not safe.

When that happens, the FDA can restrict or ban the sales of that product.

While dietary supplement use is considered to be generally safe, there are some things to think about if you're taking dietary supplements.

Always speak with your health care provider if you are:

  • Taking any medications, as some dietary supplements may have unwanted interactions.
  • Planning surgery, because some supplements can affect bleeding or response to anesthesia.
  • Pregnant or nursing, since some supplements can affect the baby.
  • Thinking about taking a dietary supplement in place of medical treatment.

When it's time to choose your dietary supplements, you might be overwhelmed with all the brands and types available. Different products may be of different quality. Ask your health care provider, pharmacist, dietitian or nutritionist for suggestions about certain formulas or brands if you're not sure which ones to choose. Always follow the label instructions, unless your health care provider has advised you differently because some supplements, such as vitamin B-6 and iron, can become toxic when taken in large amounts.

Dietary Supplement Standardization

Standardization is a process some dietary supplement manufacturers use to make sure each batch of product is same as far as dosage and quality. The United States Food and Drug Administration doesn't require dietary supplements to be standardized so you can't always be sure that what's in the bottle matches what's on the label.

What Are the Standards?

The United States Pharmacopeia (USP) is an organization that sets standards for quality for drugs and dietary supplements, as well as food ingredients. These standards are enforced for drugs, but not for dietary supplements. But supplement manufacturers can use them as a guideline. 

Since it's all up to each supplement manufacturer, the methods used may vary from brand to brand. The word 'standardized' might be displayed prominently on the label, but unless you know how the product is standardized, it doesn't mean much. Also, the cost of the supplement doesn't help -- expensive vitamins may not be any better than cheap ones.

How Do I Know If Supplements are Truly Standardized?

You may not be able to tell from the label, but you can contact the companies that manufacture the supplements and ask. Hopefully, the answer will make sense to you. If not, then maybe you should look elsewhere. You can also subscribe to, which regularly tests dietary supplements to see if they match what's stated on the label.


National Institutes of Health, Office of Dietary Supplements. "Background Information: Dietary Supplements." Accessed April 11, 2016.

Office of Dietary Supplements. National Institutes of Health. "Dietary Supplements: Background Information." Accessed April 11, 2016.

The United States Food and Drug Administration. "Dietary Supplements." Accessed April 11, 2016.

United States Pharmacopeia. "USP Dietary Supplement Standards." Accessed April 11, 2016.

University of Maryland Medical Center. "Vitamins - Introduction." Accessed April 11, 2016.

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