Several supplements can burden the liver and may cause inflammation or injury, dietitians say. Fat-soluble vitamins can build up; herbal products may interact with medicines, and some weight-loss or muscle-building products have contained undeclared ingredients.
For adults, the article cites tolerable upper limits of 3,000 micrograms daily for vitamin A and 4,000 IU for vitamin D; consistently overconsuming vitamin A may injure the liver. Dietitian Emer Delaney cites 2019 testing that found 79% of bodybuilding products were mislabeled; a separate study identified 92 muscle-building supplements with undeclared ingredients, inaccurate herbal content or hidden drugs.
Safe amounts vary by supplement and individual factors. The article says a safe dose cannot be established for herbal or muscle-building products when their contents and people’s reactions may be unpredictable. It recommends looking for independent verification, such as ConsumerLab, USP or NSF, and consulting a health professional, especially before adding supplements while taking prescription medicines.
