Benefits and Risks of Taking Dietary Supplements Menu Verywell Fit Nutrition Weight Management Nutrition Facts Nutrition Basics Diets Meal Plans Meal Delivery Services View All News Fitness and Nutrition What to Buy How We Test Products Fitness Gear Nutrition Products Tools Recipe Nutrition Calculator Weight Loss Calorie Goal BMI Calculator Body Fat Percentage Calculator Calories Burned by Activity Daily Calories Burned Pace Calculator About Us Editorial Process Meet Our Review Board Search Supplements Benefits and Risks of Dietary Supplements By Shereen Lehman, MS Shereen Lehman, MS Shereen Lehman, MS, is a healthcare journalist and fact checker. She has co-authored two books for the popular Dummies Series (as Shereen Jegtvig). Learn about our editorial process Updated on July 13, 2020 Medically reviewed Verywell Fit articles are reviewed by board-certified physicians and nutrition and exercise healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Elena Klimenko, MD Medically reviewed by Elena Klimenko, MD Elena Klimenko, MD, is a board-certified doctor in internal medicine and licensed in medical acupuncture and homeopathy. Learn about our Medical Review Board Print Tom Merton/OJO Images/Getty Images Dietary supplements are products designed to augment your daily intake of nutrients, including vitamins and minerals. Many are safe and offer significant health benefits, but there are some that pose health risks, especially if overused. Dietary supplements include amino acids, fatty acids, enzymes, probiotics, herbals, botanicals, and animal extracts. In addition to vitamins and essential minerals, popular supplements include: Chondroitin Echinacea Fish oil Garlic Ginkgo Green tea Ginseng Glucosamine St. John’s wort Saw palmetto Benefits Normally, you should be able to get all the nutrients you need from a balanced diet. However, supplements can provide you with extra nutrients when your diet is lacking or certain health conditions (such as cancer, diabetes, or chronic diarrhea) trigger a deficiency. In most cases, a multivitamin/mineral supplement will provide all the micronutrients your body needs. They are generally safe because they contain only small amounts of each nutrient (as measured by the daily value, or DV). Individual nutrients are available as supplements, usually in doses larger than your typical multivitamin. They can be used to treat a deficiency, such as an iron deficiency, or reduce the risk of a medical condition, such as hypertension. ​ For example, large doses of vitamin B3 (niacin) can help raise "good" high-density lipoprotein (HDL) cholesterol, while folic acid has long been used to reduce the risk of a birth defect called spina bifida. Antioxidants, such as vitamin C and vitamin E, may reduce the toxic effect of chemotherapy drugs (allowing patients to tolerate larger doses of chemo). Unless a specific deficiency is identified, a supplement is usually not necessary if you eat and exercise properly. The appropriate use of supplements can help you avoid side effects and toxicities associated with overuse. Risks In the United States, dietary supplements are not regulated as strictly as pharmaceutical drugs. Manufacturers do not have to prove that they are either safe or effective. The U.S. Food and Drug Administration (FDA) doesn't even determine whether dietary supplements are effective before they are shipped to market shelves. The FDA does maintain a list of tainted or potentially harmful products marketed as dietary supplements. The worst offenders are usually weight loss aids, "natural" sexual enhancement pills, and supplements targeted at bodybuilders. Supplement manufacturers have to follow certain labeling guidelines, including what they can say and not about the purported benefits. That doesn't stop manufacturers from claiming, often misleadingly, that their product can "boost the immune system" or "treat arthritis" even if there is little scientific evidence to support the claims. Generally speaking, the FDA only acts on the most serious infractions. Potential Problems While most dietary supplements are safe as long as you follow the product instructions, large doses of certain nutrients can have adverse effects. You can even overdose on certain supplements, risking serious harm and death. Among some the harmful interactions or dosing concerns: Vitamin K can reduce the effectiveness of blood thinners like Coumadin (warfarin). Vitamin E can increase the action of blood thinners, leading to easy bruising and nosebleeds. St. John’s wort can accelerate the breakdown of many drugs, including antidepressants and birth control pills, thereby reducing their effectiveness. Vitamin B6 (pyridoxine), when used for a year or more at high doses, can cause severe nerve damage. Vitamin B6 can also reduce the effectiveness of the anti-seizure drug Dilantin (phenytoin) and levodopa (used to treat Parkinson's disease). Vitamin A used with retinoid acne medications such as Accutane (isotretinoin) and Soriatane (acitretin) can causes vitamin A toxicity. Iron and calcium supplements can reduce the effectiveness of antibiotics, namely tetracyclines and fluoroquinolones, by as much as 40%. Vitamin C can cause diarrhea when taken in doses higher than the gut can absorb (but some patients can tolerate 5,000mg to 25,000mg per day). Selenium, boron, and iron supplements can be toxic if taken in large amounts. Advise your healthcare provider about any supplements you plan to take as well as any medications you are currently taking, whether they be pharmaceutical, over-the-counter, herbal, traditional, or homeopathic. For the utmost safety and quality, choose supplements tested and approved by a certifying body such as the U.S. Pharmacopeia (USP). Never use expired supplements. 9 Sources Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. U.S. Food and Drug Administration. Tips for older dietary supplement users. Afolayan AJ, Wintola OA. Dietary supplements in the management of hypertension and diabetes - a review. Afr J Tradit Complement Altern Med. 2014;11(3):248-258. doi:10.4314/ajtcam.v11i3.35 National Institutes of Health Office of Dietary Supplements. Niacin fact sheet for health professionals. Centers for Disease Control and Prevention. Folic acid helps prevent some birth defects. Singh K, Bhori M, Kasu YA, Bhat G, Marar T. Antioxidants as precision weapons in war against cancer chemotherapy induced toxicity: Exploring the armoury of obscurity. Saudi Pharm J. 2018;26(2):177-190. doi:10.1016/j.jsps.2017.12.013 U.S. Food and Drug Administration. Tainted products marketed as dietary supplements. U.S. Food and Drug Administration. Center for Biologics Evaluation and Research 2003. U.S. Food and Drug Administration. Fortify your knowledge about vitamins. National Institutes of Health Office of Dietary Supplements. Dietary supplements: What you need to know. Additional Reading Sulli MM. Ezzo D. Drug interactions with vitamins and minerals. US Pharm. 2007;1:42-55. By Shereen Lehman, MS Shereen Lehman, MS, is a healthcare journalist and fact checker. See Our Editorial Process Meet Our Review Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit Related Articles The 9 Best Supplements for Women, According to a Dietitian The 9 Best Vitamins for Women of 2022 The Best Multivitamins for Women of 2022 The 7 Best Multivitamins for Men of 2022 What You Need to Know About Vitamin E Supplements The 7 Best Multivitamins of 2022, According to a Dietitian The Best Magnesium Supplements, According to a Dietitian The 6 Best Gluten-Free Vitamin Brands, Chosen by a Dietician The Best Vitamin D Supplements of 2022, According to a Dietitian The 9 Best Vitamin Brands of 2022, According to a Dietitian The 5 Best Greens Powders of 2022, According to a Dietitian Multivitamins: Are They Worth Trying? Why Vitamin B Complex Is Important to Your Health Beef Liver Nutrition Facts and Health Benefits The Best Creatine Supplements of 2022 for Strength Training The 6 Best Pea Protein Powders of 2022, According to a Dietitian When you visit the site, Dotdash Meredith and its partners may store or retrieve information on your browser, mostly in the form of cookies. Cookies collect information about your preferences and your devices and are used to make the site work as you expect it to, to understand how you interact with the site, and to show advertisements that are targeted to your interests. You can find out more about our use, change your default settings, and withdraw your consent at any time with effect for the future by visiting Cookies Settings, which can also be found in the footer of the site. Cookies Settings Reject All Accept All