Are Supplements Safe? Here's What You Really Need to Know

Supplements are popular among the health-conscious, but they come with potential risks due to limited regulations

It's no secret the average American diet falls nutritionally short.

Indeed, an April 2016 study in Mayo Clinic Proceedings found that less than 3 percent (no, that's not a typo) of all Americans lead a healthy lifestyle, which entails hitting the four big markers: abstaining from smoking, eating well, exercising and maintaining a healthy body fat percentage.

Depressing, maybe, but no doubt a product of our busy and demanding lifestyles. So, what can we do?

Many of us turn to dietary supplements to compensate for our less-than-ideal diets.

In fact, in 2014, Americans purchased $36.7 billion worth of supplements, of which $14.3 billion were vitamin- and mineral-containing supplements, according to the National Institutes of Health's Office of Dietary Supplements (ODS).

But are supplements really necessary?

And, in the midst of recent news of dietary supplement "scams" — with products being contaminated with dangerous compounds or simply not doing what they claim to do — how can you be sure the bottle you're buying is effective (or even safe)?

Here's what you really need to know about supplements.

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Do I Really Need a Supplement?

Official recommendations set by the Dietary Guidelines Advisory Committee (DGAC) do not encourage dietary supplementation as the first line of defense for the general population.

The 2015-2020 Dietary Guidelines (established by the DGAC), which sets nutrition standards for the country, states, "nutritional needs should be met primarily from foods."

Basically, Mother Nature has our backs. The majority of us can get what we need — vitamins, minerals, fiber and other natural substances — primarily through what we eat.

But the guidelines go on to say: "In some cases, fortified foods and dietary supplements may be useful in providing one or more nutrients that otherwise may be consumed in less-than-recommended amounts." So, perhaps your diet doesn't quite cut the mustard.

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But supplementation can be dangerous. People with health conditions, pregnant women and people taking medications should be especially cautious when considering dietary supplementation.

In fact, the DGAC report says: "Dietary patterns among Americans, including typical use of fortified foods, rarely lead to overconsumption of folate, calcium, iron or vitamin D. However, each of these nutrients, as well as other nutrients, are overconsumed in some supplement users, especially those taking high-dose supplements."

Supplements: When to Say When

While not exactly encouraged, limited dietary supplementation is condoned in national guidance.

"The public may safely use dietary supplements containing RDA level of nutrients," states the DGAC report, "so long as total intake from diet plus supplements does not exceed the UL."

Two important acronyms to remember here: First, the RDA is the Recommended Dietary Allowance — the average amount of a nutrient needed to meet the requirements of nearly all healthy people.

Do you know what's in your protein powder?

The second is the UL, which is the Tolerable Upper Intake Level; the highest level of daily intake deemed safe for a given nutrient. Going above the UL can lead to some dangerous side effects.

Remember, foods and dietary supplements contribute to nutrient intake, and it can be difficult to evaluate the amount of a given nutrient you consume from all sources.

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How to Find a Supplement You Can Trust

Unfortunately, the U.S. Food & Drug Administration (FDA) does not ensure the safety of dietary supplements before they go to market.

Once on store shelves, according to the FDA, "if a serious problem associated with a dietary supplement occurs, manufacturers must report it to FDA as an adverse event. FDA can take dietary supplements off the market if they are found to be unsafe or if the claims on the products are false and misleading."

This type of regulation can lead to some dangerous consequences. News headlines in recent years have announced multiple investigations into certain supplement products and popular retailers. A 2015 investigation by the New York State Attorney General's office, for example, found Target, GNC, Walgreens and Walmart to be selling fraudulent and potentially harmful herbal supplements under their store brands.

The retailers were ordered to cease sales of these products.

And a study published June 2019 in the online issue of the Journal of Adolescent Health found that, between January 2004 and April 2015, nearly 1,000 children and young adults experienced a severe medical event (including anything from an emergency room visit to disability to death) after taking a supplement. Those who took a supplement for muscle-building, energy or weight loss were almost three times as likely to have a severe medical event as those who took vitamins.

Read more: 43 Supplements Exposed: Which Ones to Consider, Which to Avoid

3 Important Tips for Choosing Dietary Supplements

Mary Beth Augustine, RDN, CDN, a New York City-based Fellow of the Academy of Nutrition and Dietetics, gives three tips for choosing safe dietary supplements:

1. Look for products made in the U.S. Many dietary supplements manufactured outside of the country contain adulterants and contaminants.

2. Beware of false claims. If a dietary supplement claims it can cure a disease, is all-natural or has a money-back guarantee, it's a red flag. If it sounds too good to be true, it probably is.

3. Search for a stamp of certification. Look for independent third-party verification of ingredients by United States Pharmacopeia, ConsumerLab or NSF International.

To find supplements with these certifications, look for the corresponding icon (usually a small seal with the letters "USP" or "NSF") on the supplement package.

Each third-party verifier has its own quality standards, but they are generally very similar and include criteria for identity, quality, purity and potency. For instance, the USP seal confirms that the product contains the ingredients in the declared amounts as listed on the label; does not contain harmful levels of specified contaminants; and follows FDA guidelines for sanitary and well-controlled production processes.

Read more: Confused About Multivitamins? Here's How to Choose the Best One for You

Dietary supplement lines from the brands Nature Made, sold widely in retail stores, and Kirkland Signature, Costco's store brand, are USP verified.

The USP seal confirms that the product contains the ingredients in the declared amounts as listed on the label

Why Do Some Verified Supplements Cost More Than Others?

Of course, there is even variation amongst supplements with third-party quality verifications. If you want to find top-of-the-line products, look for supplement companies that set their own standards for quality control and make them transparent on their website. Julie Starkel, MS, RDN, of Starkel Nutrition in Seattle, says, "I recommend professional-line supplements for my clients because I know that they meet my criteria for quality."

Starkel starts with a simple requirement that the product meet Current Good Manufacturing Practice (CGMP) guidelines set by the FDA to ensure quality production, accurate labeling and absence of contaminants in dietary supplements.

From there, Starkel's criteria build to include significant testing. "I recommend supplement companies that test every raw material batch for potency and authentication of the listed ingredients and for the presence of contaminants like heavy metals, chemical solvents, herbicides, pesticides and aflatoxins," she says. "Some brands that meet these standards are Thorne, Pure Encapsulations, Perque and Integrative Therapeutics."

These professional-grade products tend to cost more than the average supplement on your drugstore shelf.

"Most confusing to consumers is the question of why they should pay more for one product versus a similar one, because retail brand marketing suggests they are all the same," says Starkel. But cheaper dietary supplement products are not always available in the most absorbable forms, and they don't always do what they say they'll do. "Even if a retail brand is cheaper, it may be less effective — and then you have wasted your money altogether. Why not get the high-quality product that is actually suited to your needs?" she says.

Read more: All About Vitamin C: How Much Should You Really Be Getting?

Starkel recommends Emerson Ecologics, an online distributor of many brands of dietary supplements, because the company has a "medical board of advisors who espouse similar quality criteria" to those mentioned above.

Lastly, take a look at ingredient labels.

Some supplements contain many fillers and undesirable ingredients, like sweeteners, says Starkel. Similar to choosing a healthy food product, steer clear of anything with a lengthy ingredient label.