Basics Nutrients You Get From a Multivitamin By Joel Fuhrman, MD facebook twitter Joel Fuhrman, MD, is a board-certified physician focused on nutrition and natural healing. He's a New York Times best-selling author and TEDx speaker. Learn about our editorial process Joel Fuhrman, MD Medically reviewed by a board-certified physician Updated on December 18, 2020 Print Multivitamins. Getty Images Credit: Jed Share Do you take a vitamin supplement every day? More than half of all Americans do, usually in the form of a multivitamin and mineral. But do you really know what you are ingesting in an effort to promote good health? When it comes to multivitamins, my advice is to proceed with caution. Do You Even Need to Take a Multivitamin? No supplement or multivitamin can take the place of a nutrient-dense, plant-rich diet with its fiber and a full spectrum of both discovered and yet-to-be-discovered nutrients. However, taking a well-designed multivitamin and mineral supplement can be an important contributor to good health. That’s because very few people eat so healthfully that they get the ideal amount of every vitamin and mineral needed in optimal amounts. For example, iodine, zinc, vitamin B12, vitamin K2, and vitamin D3 are difficult to obtain in optimal levels through plant foods. Therefore, using a safe, well-designed multivitamin makes sense. Why Can’t Diet Do it All? Although the vast majority of our vitamins and minerals should come from foods, even a healthy, well-planned diet could be lacking in certain essential nutrients. Here are five key nutrients your body might not be getting from your healthful diet: Vitamin B12 Made by microorganisms and not present in plant foodsDeficiency is more common in vegans and those ages 60 and olderImportant in red blood cell production, nervous system function, DNA synthesisMaintaining sufficient B12 levels may help to protect against Alzheimer’s disease B12 deficiency causes anemia, depression, confusion, fatigue, digestive issues, nerve damage Zinc Vegans, vegetarians, and flexitarians tend to require more zinc because zinc from plant products is less readily absorbedImportant in immune function, growth, skin health, wound healing, reproduction, protein structure, neurotransmitter, and insulin secretionLow zinc levels could lead to impaired immune function, a tendency toward anxiety and depression (especially in women), and zinc adequacy may protect against breast and prostate cancers Iodine Those on plant-centered diets who eliminate seafood and restrict iodized salt are most at risk of deficiencyEssential for the production of thyroid hormone and thyroid functionIodine deficiency causes hypothyroidism, enlargement of the thyroid gland (goiter), and pregnancy-related problems Vitamin K2 Supplementation is especially important for vegans or near-vegans since only small amounts are produced by the body and the nutrient is scarce in plant foodsImportant for optimal bone health and heart health with aging Low K2 associated with a higher potential for fractures and bone loss and lower bone mineral density Vitamin D Those at risk of insufficiency are most people who work indoors or live in cool climates since sunlight is the primary source of vitamin DFor many people, adequate vitamin D levels are difficult to achieve from sunlight alone without damaging the skinImportant in building and supporting bone strength by enhancing calcium absorption; supports the immune systemLow vitamin D linked to a higher risk of cancer, diabetes, cardiovascular disease, depression, and autoimmune conditions Is There a Downside to Supplementation? How can you be sure that what you are taking is worth the expense and the daily dedication, and most importantly, is safe? When I began looking for multivitamin and mineral supplements that I could give to patients with confidence, I was disappointed. Most multivitamins contain ingredients that could potentially be harmful, making the overall supplement cause more harm than good. Certain common ingredients in multivitamins like copper, beta-carotene, vitamin A, and vitamin E have been suggested in studies to have health-degrading, even cancer-promoting side effects. The multivitamins on the market all had too much of some things and too little of others. Even taking too much of something useful can be harmful. Plus, they almost always contained risky ingredients. For example, long-term studies document that folic acid supplementation promotes breast and prostate cancer. As a result, I designed my own line of multivitamins that contain no folic acid, copper, beta-carotene, or vitamin A, all of which have been shown in studies to be harmful in excess amounts. The Best Use of a Multivitamin Taking a multivitamin can give you a baseline of vitamins and minerals to help protect against nutrient deficiencies. Especially for people who don't consume enough fruits and vegetables, a multivitamin may help them to achieve their daily needs. Aim to choose a multivitamin that has 100% of the RDA for most vitamins and minerals, especially zinc and vitamins B12, C, D, and K. Avoid multivitamins that have excessive amounts of vitamins and minerals. Use caution when purchasing vitamins and minerals that make miraculous claims. If you have an underlying health condition, always consult with a health care provider before starting supplements, especially if you take medication. Was this page helpful? Thanks for your feedback! Looking to lose weight? Our nutrition guide can help you get on the right track. Sign up and get it free! Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article 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. Foster M, Chu A, Petocz P, Samman S. Effect of vegetarian diets on zinc status: a systematic review and meta-analysis of studies in humans. J Sci Food Agric 2013, 93:2362-2371. Hooshmand B, Solomon A, Kareholt I, et al. Homocysteine and holotranscobalamin and the risk of Alzheimer disease: a longitudinal study. Neurology 2010, 75:1408-1414. Office of Dietary Supplements, National Institutes of Health. Dietary Supplement Fact Sheet: Vitamin B12 [http://ods.od.nih.gov/factsheets/VitaminB12/] Office of Dietary Supplements, National Institutes of Health. Dietary Supplement Fact Sheet: Zinc. [http://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/] Swardfager W, Herrmann N, Mazereeuw G, et al. Zinc in depression: a meta-analysis. Biol Psychiatry 2013, 74:872-878.