Thyroid Disease Living With The Low-Iodine Diet for Radioactive Iodine Treatment Adapt Your Diet to Improve Your Outcome By Mary Shomon Mary Shomon Facebook LinkedIn Twitter Mary Shomon is a writer and hormonal health and thyroid advocate. She is the author of "The Thyroid Diet Revolution." Learn about our editorial process Updated on August 20, 2021 Medically reviewed by Ana Maria Kausel, MD Medically reviewed by Ana Maria Kausel, MD on July 20, 2020 Facebook Twitter Ana Maria Kausel, MD, is a double board-certified endocrinologist affiliated with Mount Sinai St. Luke's/Mount Sinai West in New York City. Learn about our Medical Review Board Print If you are going to have radioactive iodine treatment for your thyroid disease, you will have to prepare in advance by following a low-iodine diet. Doing so for at least two weeks prior to receiving your treatment makes your thyroid more receptive to the radioactive iodine, increasing its effectiveness. You'll need to continue to maintain this diet until your iodized radiation treatment is complete. Radioactive iodine is taken as a pill to permanently reduce your thyroid gland activity. There are a few different thyroid conditions that may be treated with radioactive iodine therapy, including several types of thyroid cancer as well as some kinds of benign (noncancerous) hyperthyroidism. Betsie Van Der Meer / Taxi / Getty Images What to Avoid There are certain restrictions when you are on a low-iodine diet. Some foods either contain iodine or increase your absorption of iodine. Foods to avoid while you are on a low-iodine diet include: Iodized saltDairy products—cheese, cream, yogurt, butter, ice creamEgg yolks, whole eggs, and foods containing whole eggsSeafood fish, shellfish, seaweed, kelpFoods that contain the additives: carrageen, agar-agar, algin, alginatesCured and corned foods—ham, lox, corned beef, sauerkrautBread products that contain iodate dough conditionersMilk chocolateSoy products — sauce, soy milk, tofuAny supplements that contain iodine, especially seaweed, kelp, and dulseBlackstrap molasses (unsulfured molasses is fine) Salt is the most common source of iodine, but low iodine has nothing to do with sodium, which is also found in salt. While you are on your low-iodine diet, sodium is fine, as long as it's from other sources. Special Considerations Foods and medications may be processed with iodine-containing Red Dye #3 (erythrosine). Your doctor or pharmacist can tell you if any of your regular medications contain iodine, in which case you may need to change to a different prescription before and throughout your radioactive iodine treatment. You can find information about the iodine content in any of your over-the-counter pills by checking the manufacturer's website or by asking your pharmacist. Be sure to consult with your doctor before discontinuing any red-colored medicines. Most commercial vitamin preparations have iodine added as an essential nutrient. Read labels carefully and ensure that you are taking an iodine-free vitamin while following the low-iodine diet. What to Eat Eliminating the above foods may seem quite limiting, but there are many foods that you can eat while on a low-iodine diet. Many lament about the need to cut out salt, but know that it's fine to use non-iodized salt if you desire. Foods you can eat while on a low-iodine diet include: Non-iodized saltFresh, canned, and frozen vegetables in cooked or raw formUnprocessed meats, including beef, pork, and poultryPasta and riceSome breadMatzoEgg whitesFresh or canned fruit in cooked or raw formUnsalted nutsUnsalted nut butters such as peanut butter and almond butterPopcorn with non-iodized saltDark, non-dairy chocolateIodine-free spicesVegetable oils Soft drinks, coffee, tea Prepared Foods and Eating Out Even if you pick up a prepared dish or order something off a menu that seems to be made from foods that are fine for a low-iodine diet, you need to exercise some caution. While some ingredients in a dish may be quite obvious, others—like those in a "special sauce"—may not be. Ask questions of your server. You may also be able to request some restaurant or catered foods without salt or with non-iodized salt. Baked goods are often made with iodized salt, salted butter, egg yolks, and/or dairy products. Seek out specialty grocery stores and bakeries that sell items prepared with low iodine. Preparing these items yourself, however, may be easier. Eating Well on a Low-Iodine Diet A Word From Verywell Radioactive iodine treatment can be a very effective method of addressing thyroid disease. The process requires a good deal of planning and preparation on your part, between following a low-iodine diet, adjusting some of your medications ahead of time, and so on. Be sure you are clear on the instructions you need to follow to ensure that you get the most out of your treatment. Frequently Asked Questions What are the side effects of a low-iodine diet? There are no negative effects to eating low-iodine food. You might experience some positive effects, though, if you stick with the diet long-term. The recommendations for the DASH diet, which is used to treat hypertension, are similar to recommendations for a low-iodine diet, so you may see your blood pressure and cholesterol levels improve. Learn More: Benefits of the DASH diet What are some low-iodine diet snacks? Your best options are fresh fruits and vegetables, but other recommendations include:Dried fruitApplesauceUnsalted nutsUnsalted peanut butter and rice cakesMatzoh or other unsalted crackersFruit juice Learn More: Where to Watch for Hidden Salt with Iodine Which foods have iodine? Only a small number of foods have iodine naturally occurring in them. These include seaweed, some fish, and dairy. Most dietary iodine comes from foods that have iodine added, especially iodized salt, seasonings, commercial baked goods, and other processed foods. Learn More: Why You Need Iodine Was this page helpful? Thanks for your feedback! Losing weight with thyroid disease can be a struggle. Our thyroid-friendly meal plan can help. Sign up and get yours 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 Health 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. Lim CY, Kim JY, Yoon MJ, Chang HS, Park CS, Chung WY. Effect of a Low Iodine Diet vs. Restricted Iodine Diet on Postsurgical Preparation for Radioiodine Ablation Therapy in Thyroid Carcinoma Patients. Yonsei Med J. 2015;56(4):1021–1027. doi: 10.3349/ymj.2015.56.4.1021 Lee KJ, Chang SO, Jung KY. Experiences with a low-iodine diet: A qualitative study of patients with thyroid cancer receiving radioactive iodine therapy. Eur J Oncol Nurs. 2016 Aug;23:43-50. doi: 10.1016/j.ejon.2016.02.011. Epub 2016 May 7 University of Michigan, Department of Radiology, "Low Iodine Diet Guidelines" Bazzano LA, Green T, Harrison TN, Reynolds K. Dietary approaches to prevent hypertension. Curr Hypertens Rep. 2013;15(6):694-702. doi:10.1007%2Fs11906-013-0390-z American Thyroid Association. Low Iodine Diet. Memorial Sloan Kettering Cancer Center. Low-Iodine Diet. Updated November 4, 2019. Additional Reading Sawka AM, Ibrahim-Zada I, Galacgac P, et al. Dietary iodine restriction in preparation for radioactive iodine treatment or scanning in well-differentiated thyroid cancer: a systematic review. Thyroid. 2010 Oct;20(10):1129-38. doi: 10.1089/thy.2010.0055.