If you’re like most Americans, you probably down a daily multivitamin or take turmeric pills from time to time. About 58% of U.S. adults 20 and older, including 64% of women and 51% of men, reported consuming a dietary supplement in the past 30 days, according to the 2017–18 National Health and Nutrition Examination Survey. A 2024 poll from the Council for Responsible Nutrition (CRN), a dietary supplement trade association, suggests usage is even higher, with 75% of U.S. adults 18 and older taking dietary supplements.
Nearly all users in the CRN survey (91%) said supplements are essential to maintaining their health—which is why it’s so troubling that supplement-spurred liver damage is skyrocketing. A 2022 study published in the journal Liver Transplantation found that drug-induced acute liver failure tied to herbal and dietary supplements had increased eightfold from 1995 through 2020. What’s more, herbal and dietary supplements account for roughly 20% of liver toxicity cases nationwide, according to 2017 research published in the journal Hepatology.
This doesn’t mean you should immediately toss out your protein powder or vitamin D capsules. Dietary supplements can indeed help you meet your daily requirements of essential nutrients and improve or maintain your overall health, the Food and Drug Administration says. But they come with risks.
Last year, researchers at the University of Michigan estimated that 15.6 million Americans consume products containing at least one of these six botanicals linked to liver damage:
These supplements are taken for everything from allergies to menstrual cramps to weight loss. And that’s not all the team uncovered.
“In a previous study, we found that there was a great deal of mislabeling of some of these products,” senior author Dr. Robert Fontana, a Michigan Medicine hepatologist, said in an August news release. “We performed analytical chemistry and found about a 50% mismatch between stated ingredients on the label and what they actually contained, which is quite alarming. If you buy a supplement and it says it has a certain ingredient, it’s basically a coin flip if that’s true or not.”
In addition, numerous studies have found supplements to be contaminated with toxic heavy metals.
Dietary supplements aren’t FDA-approved
While the FDA regulates supplements, the agency doesn’t review them for safety, quality, and effectiveness as it does with drug approvals. And though supplements are typically found in the pharmacy sections of both online and brick-and-mortar retailers, the FDA regulates them as food, not drugs.
It’s up to manufacturers to properly label their products, which the FDA reviews after they hit the market. The agency keeps a searchable database of warning letters it has sent to companies accused of problems such as false claims or poor manufacturing practices. The FDA also encourages consumers to report problems with dietary supplements.
Tell your doctor which dietary supplements you take
You may not feel you need to tell your health care provider you’re taking something as mundane as vitamin C gummies, but there’s a reason the FDA encourages it. Some supplements may negatively interact with certain medications you’re taking, and your doctor can help determine which supplements safely suit your health goals.
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Take dietary supplements as intended
Don’t fall for “megadosing” trends that promise speedy or exaggerated results. While rare, it is possible to fatally overdose on dietary supplements.
The Office of Dietary Supplements, part of the National Institutes of Health, has established daily upper limits (ULs) for safe consumption. For example, adults shouldn’t consume more than 100 micrograms of vitamin D in a day.
“Supplements, in the U.S. at least, are not supposed to have more than the UL in any single dose,” Joanne Slavin, PhD, a professor in the food science and nutrition department at the University of Minnesota, previously told Fortune. “But you could take 10 doses—we can’t control that.”
For more on dietary supplements:
- What’s the scoop on protein powder? Nutrition experts share 3 things to know about the popular supplement
- The dark side of daily vitamin D supplements: After a man died from an ‘overdose’ in the U.K., experts explain how much is healthy
- The best time to take your supplements depends on these 2 factors, experts say
- 4 best supplements for an energy boost, according to experts
- Some protein powders contain cancer-causing toxins, new study shows, and these 3 types are the worst offenders
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