Using data from a national registry, researchers found that herbal and dietary supplements were implicated in 18% of liver injury cases caused or suspected of being caused by drugs or supplements from 2003 to 2011.
Bodybuilding and weight loss supplements were by far the biggest offenders, linked to 34% and 26% of 93 cases studied, respectively, says researcher Victor J. Navarro, MD, a professor of medicine, pharmacology, and experimental therapeutics at Thomas Jefferson University in Philadelphia.
Still, the study is not meant to scare people, Navarro says. Many supplements are beneficial to your health, he says, ticking off a long list that includes calcium and vitamin D supplements and multivitamins made by reputable companies.
Plus, the absolute risk of any one person developing supplement-associated liver injury may be very small, he says.
Drug-Linked Liver Injury a Major Problem
Liver damage from medication is one common reason that drugs are pulled off the market. And certain supplements have been linked to drug-associated liver injury, Navarro says.
About 40% of Americans take herbal and dietary supplements, which do not require a prescription and are not tightly regulated by the FDA. Yet there’s a lack of solid information about their side effects, including liver-related toxicities, Navarro says.
So the researchers turned to the National Institutes of Health-funded Drug-Induced Liver Injury Network (DILIN). It’s a nationwide registry of people who experience liver injury within six months of using certain drugs or alternative-medicine herbal products and supplements. A majority were male, white, and overweight.
Researchers asked the people what supplements they were taking. Most still had the products at home and brought them in for testing to determine whether they actually contained what the labels said they did, among other factors.
People also underwent a battery of exams with the goal of better understanding supplement-associated liver ills.