Herbal dietary supplements are traditionally used to alleviate or prevent certain medical conditions, including digestive problems and depression, or to improve an individual’s quality of life. While these supplements and other medicinal herbs fall under the jurisdiction of the Federal Drug Administration (FDA), the Dietary Supplement Health and Education Act of 1994 gives responsibility for testing and ensuring safety of products to the manufacturer. Recent reports indicate that some supplements may contain potentially harmful substances in addition to their active ingredients, but consumers are often not aware of these ingredients or of the way that supplements or vitamins may interact with other medications.
The FDA defines “dietary supplements” as products taken by mouth which contain vitamins, minerals, herbs or other botanicals, amino acids, and/or other substances such as enzymes or metabolites. A national survey found that 52 percent of American adults had used supplements within the last 30 days, and the popularity of supplements in the United States continues to increase. Among the most commonly reported products were multivitamins (35 percent), vitamins E and C (12-13 percent), calcium (10 percent), and B-complex vitamins (5 percent). Though research has shown that some dietary supplements, including folic acid and calcium, are effective in preventing or treating diseases, in the case of other supplements, additional research is needed to prove the efficacy of their use.
While some supplements have not yet been proven safe and effective, others have been linked to serious adverse events by clinical research or case reports. Consumer Reports has documented twelve supplements including colloidal silver, comfrey, and kava, which have been linked to serious health problems such as permanently turning the skin a bluish color and damage to the liver and other organs. A recent study of 40 herbal dietary supplements by the U.S. Government Accountability Office (GAO) found trace amounts of at least one potentially hazardous contaminant in 37 of the products tested. Wide variation has also been seen in the amount of active compounds in supplements, and some, including St. John’s wort, have been found to negatively affect the efficacy of prescription medications.
Because of the potential for interactions with prescription medications, it is important that consumers consult their physician before taking any supplements. Consumers should also be aware that some claims made by manufacturers about the benefits of particular supplements may not have been verified. Though FDA regulations do not permit manufacturers or retailers to make claims that their products can treat, prevent, or cure specific conditions, these regulations are not always adhered to. Some individuals’ health may benefit from the use of certain supplements, but experts advise consumers to be aware of the potential risks of taking supplements and ask their doctor if there is the potential for any type of drug interaction.