About Dietary Supplements
When people think about dietary supplements, vitamins and minerals are often the first thing that come to mind. But the term "dietary supplement" actually encompasses a broad range of products that extend well beyond these traditional nutrients. Herbal and botanical products like St. John's Wort and ginseng are considered dietary supplements, as are amino acids such as lysine and tryptophan. Even animal extracts like shark cartilage and fish oils fall into the category of dietary supplements.
Use of dietary supplements in the United States has climbed rapidly over the last decade. Surveys show that roughly half of the U.S. population now uses some type of dietary supplement. The dietary supplement industry is one of the fastest growing industries in the world with current estimated sales of over $20 billion a year.
Most supplement users take these products because they believe that they’ll help them feel better and stay healthier. In some cases, they might be correct. Calcium supplements may reduce the risk of osteoporosis; folic acid can help prevent birth defects. There is growing evidence that chondroitin sulfate might help individuals suffering from arthritis, and studies suggest that fish oil supplements reduce the risk of sudden death from heart attacks.
But, for the vast majority of dietary supplements on the market today, there's little credible evidence that they offer significant health benefits. Although Echinacea is widely used to boost the immune system and help fight off colds, scientific studies don't suggest it works. (Some studies have found that long-term use of Echinacea actually lowers immunity.) Claims that ginkgo biloba enhances memory are also largely unsubstantiated.
Safety issues are a concern. Many people assume that all supplements are safe simply because they're "natural". In fact, as the use of supplements increases, a growing number of potential hazards associated with their use are coming to light. For example, use of ginkgo may increase the risk of bleeding, kava-containing dietary supplements can cause severe liver damage and large amounts of zinc can have detrimental effects on cholesterol levels.
Some people assume that the Food and Drug Administration (FDA) would keep unsafe supplements from ever reaching the market. In fact, most supplements do not require FDA approval, and many reach the marketplace without undergoing a safety review. Unlike pharmaceuticals which must undergo extensive safety testing before they can be sold, research studies to prove a supplement's safety are not required.
In order to remove a dietary supplement from the market, the FDA must prove that the product is unsafe. It took over 30 deaths before the FDA was able to accomplish that task with the supplement, Ephedra. For years, Ephedra was legally sold and widely used to aid weight control and boost sports performance and energy. However, the FDA banned sales of the product in February 2004 when it determined that use of the supplement was linked to significant adverse health outcomes, including heart ailments and strokes.
Unfortunately, proving that a supplement is unsafe isn't always easy, and many potentially dangerous products remain on the market. That’s why it’s important to take precautions when using them.
Always inform your physician about the supplements you're taking, particularly those that you take on a long-term basis. Your physician can help you evaluate the real benefits - and real risks - that they offer. Dangerous interactions between the supplements and prescription and over-the-counter medications you're taking can also be avoided.
If you experience any side effects from dietary supplements you are taking, report them to MedWatch, the FDA's Safety Information and Adverse Event Reporting Program, at (888) 332-1088.
Monday - Friday
8:00am - 5:00pm
Tel: (626) 430-9820
County of Los Angeles Public Health
Toxicology & Environmental Assessment Branch