Dr. Victor Navarro, the chairman of the hepatology division at Einstein Healthcare Network in Philadelphia, said that while liver injuries linked to supplements were alarming, he believed that a majority of supplements were generally safe.
Most of the liver injuries tracked by a network of medical officials are caused by prescription drugs used to treat things like cancer, diabetes and heart disease, he said.
But the supplement business is largely unregulated. In recent years, critics of the industry have called for measures that would force companies to prove that their products are safe, genuine and made in accordance with strict manufacturing standards before they reach the market.
But a federal law enacted in 1994, the Dietary Supplement Health and Education Act, prevents the
Food and Drug Administration from approving or evaluating most supplements before they are sold. Usually the agency must wait until consumers are harmed before officials can remove products from stores. Because the supplement industry operates on the honor system, studies show, the market has been flooded with products that are adulterated, mislabeled or packaged in dosages that have not been studied for safety.
The new research found that many of the products implicated in liver injuries were bodybuilding supplements spiked with unlisted steroids, and herbal pills and powders promising to increase energy and help consumers lose weight.