Table of ContentsView AllTable of ContentsOverviewFoods to AvoidFoods AllowedChallengesDining OutRecipes and CookbooksFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Overview
Foods to Avoid
Foods Allowed
Challenges
Dining Out
Recipes and Cookbooks
Frequently Asked Questions
A low-iodine diet is prescribed before diagnosticradioactive iodineuptake (RAIU) tests and before radioactive iodine treatments. The RAIU test is an imaging scan used to check thyroid health. Radioactive iodine (RAI) treatment is used to treat thyroid diseases such ashyperthyroidism, Graves disease, andthyroid cancer.
The low-iodine diet is a special diet that limits the amount ofiodineyou can consume through foods and beverages. This article gives an overview of the thyroid gland, RAIU scans, RAI treatment, which foods to avoid and include on a low-iodine diet, and overcoming the challenges of the diet.
Verywell / Tim Liedtke
Iodine is a trace mineral or element found in some foods, some types of salt, and dietary supplements. It does not naturally occur in the body, so it needs to come from these foods or supplements.
Thethyroid glanduses dietary iodine to produce thyroid hormones that regulate metabolism. Too little or too much iodine can cause or worsen thyroid disease.
Iodine’s Role in Thyroid Health
A low-iodine diet is necessary when preparing for a radioactive iodine uptake (RAIU) test or treatment. This diet is required to “starve” the thyroid of iodine and reduce the amount of resident iodine. Lowering amounts of resident iodine makes the thyroid “iodine hungry.”
Decreased amounts of resident iodine makes it easier for the RAI to get into the thyroid or thyroid cancer tissue.
When it’s time for the RAIU scan or treatment, you will take radioactive iodine (RAI) in capsule form. RAI uptake into the thyroid cells allows them to be visualized on a diagnostic imaging scan. It can also destroy tumor cells when this therapy is used for thyroid cancer treatment.
The low-iodine diet may sound simple because you only need to eliminate one mineral from your diet—iodine. But it requires some planning. If you eat a lot of pre-packaged or frozen foods or eat out, you will need to make some significant adjustments while on a diet.
Iodized, Non-iodized, and Kosher SaltThe biggest rule of the diet is to eat foods that are low in iodine. Since most salt is iodized (meaning it has iodine added), you need to avoid iodized salt and foods containing iodized salt. Instead, you can use non-iodized and kosher salt because they do not contain iodine.
Iodized, Non-iodized, and Kosher Salt
The biggest rule of the diet is to eat foods that are low in iodine. Since most salt is iodized (meaning it has iodine added), you need to avoid iodized salt and foods containing iodized salt. Instead, you can use non-iodized and kosher salt because they do not contain iodine.
The Thyroid Cancer Survivors Association provides recommendations regarding which foods are permitted and prohibited when following a low-iodine diet. This organization is considered a trustworthy and knowledgeable source of information.
Most low-iodine diets take less than 50 micrograms (mcg) of iodine per day.However, it’s best to ask your healthcare provider to ensure you don’t have a different requirement. The following have higher levels of iodine and should be avoided while on a low-iodine diet:
Foods to Include
Iodine Content of High Iodine FoodsThe following values for the foods listed below come from the National Institute of Health (NIH). These values can help guide you when you are estimating the iodine levels of food.Foods higher in iodine:Bread with iodate: Two slices of bread made with iodate dough conditioner—320 micrograms (mcg)Cod: Three ounces of baked cod—158 microgramsSeaweed: Two tablespoons of nori seaweed—116 microgramsOysters: Three ounces of cooked oysters—93 microgramsYogurt:3/4 cup of plain Greek, nonfat yogurt—87 microgramsIodized salt: 1/4 teaspoon—76 microgramsEggs: One large hard-boiled egg—6 microgramsCheese: 1-ounce cheddar cheese—15 micrograms
Iodine Content of High Iodine Foods
The following values for the foods listed below come from the National Institute of Health (NIH). These values can help guide you when you are estimating the iodine levels of food.Foods higher in iodine:Bread with iodate: Two slices of bread made with iodate dough conditioner—320 micrograms (mcg)Cod: Three ounces of baked cod—158 microgramsSeaweed: Two tablespoons of nori seaweed—116 microgramsOysters: Three ounces of cooked oysters—93 microgramsYogurt:3/4 cup of plain Greek, nonfat yogurt—87 microgramsIodized salt: 1/4 teaspoon—76 microgramsEggs: One large hard-boiled egg—6 microgramsCheese: 1-ounce cheddar cheese—15 micrograms
The following values for the foods listed below come from the National Institute of Health (NIH). These values can help guide you when you are estimating the iodine levels of food.
Foods higher in iodine:
Iodine Content of Low-Iodine FoodsFoods lower in iodine:Apple juice: 1 cup apple juice—1 microgramRice: 3/4 cup brown cooked rice—1 microgramSea salt (non-iodized)—1/4 teaspoon—less than 1 microgramCorn: 1/2 cup canned—0 microgramsBroccoli: 1/2 cup boiled—0 microgramsBanana:Large banana—0 microgramsPasta: 1 cup enriched pasta boiled without iodized salt—0 micrograms
Iodine Content of Low-Iodine Foods
Foods lower in iodine:Apple juice: 1 cup apple juice—1 microgramRice: 3/4 cup brown cooked rice—1 microgramSea salt (non-iodized)—1/4 teaspoon—less than 1 microgramCorn: 1/2 cup canned—0 microgramsBroccoli: 1/2 cup boiled—0 microgramsBanana:Large banana—0 microgramsPasta: 1 cup enriched pasta boiled without iodized salt—0 micrograms
Foods lower in iodine:
Among the challenges of following a low-iodine diet is that you may find conflicting information about which foods are allowed and prohibited on the diet. One source may say that you should only avoid potato skins, while another may suggest that you cannot eat potatoes at all.
Confusing information can add to the challenge of this already restrictive diet. Don’t hesitate to ask your healthcare provider for a referral to anutritionistif you want personalized advice and guidance.
Tips to Help You Plan AheadHere are a few tips to help plan ahead for a low-iodine diet:Buy non-iodized salt (replace all of your salt shakers with it)Use olive oil to replace butter or margarineMake fresh oil and vinegar dressingStock up on pasta and frozen vegetables (don’t use iodized salt to boil pasta or cook vegatables)Keep natural peanut butter, jam, and honey on handBake or buy bread without iodate dough conditioner (matzo is a good choice, be sure to check the label)Shop the outer perimeter of the grocery store (fresh fruits, veggies, and meat)Limit meat to 6 ounces per day
Tips to Help You Plan Ahead
Here are a few tips to help plan ahead for a low-iodine diet:Buy non-iodized salt (replace all of your salt shakers with it)Use olive oil to replace butter or margarineMake fresh oil and vinegar dressingStock up on pasta and frozen vegetables (don’t use iodized salt to boil pasta or cook vegatables)Keep natural peanut butter, jam, and honey on handBake or buy bread without iodate dough conditioner (matzo is a good choice, be sure to check the label)Shop the outer perimeter of the grocery store (fresh fruits, veggies, and meat)Limit meat to 6 ounces per day
Here are a few tips to help plan ahead for a low-iodine diet:
Eating outis almost nearly impossible while following alow-iodine diet. You can’t guarantee what type of salt a restaurant uses in their recipes. Foods served in fast food restaurants are mostly processed and contain salt, so they should be avoided as well.
When you season your food and cook at home, be sure to use non-iodized salt or kosher salt instead of iodized salt. Try using fresh herbs such as basil or cilantro to liven up your meals. You can prepare a variety of foods as long as the ingredients fit the criteria above.
Cooking can be challenging, even if you are already a good cook because it is hard to learn a new way of preparing food. The Thyroid Cancer Survivors Association offers alow-iodine cookbookthat can be downloaded for free. It boasts over 300 low-iodine recipes and is a favorite among those following a low-iodine diet.
Example Meal PlanThe following are a few examples of low-iodine meals to help you get started:Breakfast:Orange juice, oatmeal, coffeeOne slice of toast (use bread without iodate dough conditioner) with natural jam or honey, cream of wheat, fresh fruitLunch:Fresh beef or turkey (up to 6 ounces per day), pasta (cooked with non-iodized salt), green beans, an apple, and graham crackersHomemade vegetable soup and a salad with homemade oil and vinegar dressingDinner:Salad with homemade oil and vinegar dressing, fresh meat (up to 6 ounces per day), broccoli, fresh fruitPasta (no iodized salt) sautéed with olive oil and vinegar, fresh basil and tomatoes, non-iodized salt, and pepper
Example Meal Plan
The following are a few examples of low-iodine meals to help you get started:Breakfast:Orange juice, oatmeal, coffeeOne slice of toast (use bread without iodate dough conditioner) with natural jam or honey, cream of wheat, fresh fruitLunch:Fresh beef or turkey (up to 6 ounces per day), pasta (cooked with non-iodized salt), green beans, an apple, and graham crackersHomemade vegetable soup and a salad with homemade oil and vinegar dressingDinner:Salad with homemade oil and vinegar dressing, fresh meat (up to 6 ounces per day), broccoli, fresh fruitPasta (no iodized salt) sautéed with olive oil and vinegar, fresh basil and tomatoes, non-iodized salt, and pepper
The following are a few examples of low-iodine meals to help you get started:
Breakfast:
Lunch:
Dinner:
Summary
The low-iodine diet is a special diet that limits the amount ofiodineyou can consume through foods and beverages. It’s often used before diagnostic radioactive iodine uptake (RAIU) tests and before radioactive iodine treatments.
Low-iodine diets are necessary before these tests or treatments to “starve” the thyroid of iodine, so the radioactive iodine (in capsule form) can easily get into the thyroid or thyroid cancer tissue.
A Word From Verywell
Frequently Asked QuestionsWhile not all breads have high amounts of iodine, those made with dough conditioner that includes potassium or calcium iodate have the highest amount of iodine. Other foods with high amounts include seaweed, seafood, oysters, iodized salt, dairy, eggs, and liver.Not following a low-iodine diet before a radioactive uptake test may change the results of the thyroid scan. This will affect how your healthcare providers set up your treatment plan.If the radioactive iodine is a treatment, it may not be as effective.Your healthcare providers will ask you to follow a low-iodine diet seven to 14 days before a RAI scan or radioactive iodine treatment.Some people choose to start the diet a couple of days sooner to get used to it.You may also be asked to stay on the diet for one to two days after the scan or treatment.
While not all breads have high amounts of iodine, those made with dough conditioner that includes potassium or calcium iodate have the highest amount of iodine. Other foods with high amounts include seaweed, seafood, oysters, iodized salt, dairy, eggs, and liver.
Not following a low-iodine diet before a radioactive uptake test may change the results of the thyroid scan. This will affect how your healthcare providers set up your treatment plan.If the radioactive iodine is a treatment, it may not be as effective.
Your healthcare providers will ask you to follow a low-iodine diet seven to 14 days before a RAI scan or radioactive iodine treatment.Some people choose to start the diet a couple of days sooner to get used to it.You may also be asked to stay on the diet for one to two days after the scan or treatment.
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Thyroid Cancer Survivor Association.Low-iodine diet.Ju DL, Park YJ, Paik HY, Song Y.The impact of low adherence to the low-iodine diet on the efficacy of the radioactive iodine ablation therapy.Clin Nutr Res. 2015;4(4):267-271. doi:10.7762/cnr.2015.4.4.267National Institutes of Health, Office of Dietary Supplements.Iodine: fact sheet for health professionals.University of Wisconsin Health Division of Nuclear Medicine Procedure/Protocol.Low iodine diet.Lee M, Lee Y, Jeon T, et al.Low iodine diet for one week is sufficient for adequate preparation of high dose radioactive iodine ablation therapy of differentiated thyroid cancer patients in iodine-rich areas.Thyroid. 2014;24(8):1289-96. doi:10.1089/thy.2013.0695
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Thyroid Cancer Survivor Association.Low-iodine diet.Ju DL, Park YJ, Paik HY, Song Y.The impact of low adherence to the low-iodine diet on the efficacy of the radioactive iodine ablation therapy.Clin Nutr Res. 2015;4(4):267-271. doi:10.7762/cnr.2015.4.4.267National Institutes of Health, Office of Dietary Supplements.Iodine: fact sheet for health professionals.University of Wisconsin Health Division of Nuclear Medicine Procedure/Protocol.Low iodine diet.Lee M, Lee Y, Jeon T, et al.Low iodine diet for one week is sufficient for adequate preparation of high dose radioactive iodine ablation therapy of differentiated thyroid cancer patients in iodine-rich areas.Thyroid. 2014;24(8):1289-96. doi:10.1089/thy.2013.0695
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Thyroid Cancer Survivor Association.Low-iodine diet.Ju DL, Park YJ, Paik HY, Song Y.The impact of low adherence to the low-iodine diet on the efficacy of the radioactive iodine ablation therapy.Clin Nutr Res. 2015;4(4):267-271. doi:10.7762/cnr.2015.4.4.267National Institutes of Health, Office of Dietary Supplements.Iodine: fact sheet for health professionals.University of Wisconsin Health Division of Nuclear Medicine Procedure/Protocol.Low iodine diet.Lee M, Lee Y, Jeon T, et al.Low iodine diet for one week is sufficient for adequate preparation of high dose radioactive iodine ablation therapy of differentiated thyroid cancer patients in iodine-rich areas.Thyroid. 2014;24(8):1289-96. doi:10.1089/thy.2013.0695
Thyroid Cancer Survivor Association.Low-iodine diet.
Ju DL, Park YJ, Paik HY, Song Y.The impact of low adherence to the low-iodine diet on the efficacy of the radioactive iodine ablation therapy.Clin Nutr Res. 2015;4(4):267-271. doi:10.7762/cnr.2015.4.4.267
National Institutes of Health, Office of Dietary Supplements.Iodine: fact sheet for health professionals.
University of Wisconsin Health Division of Nuclear Medicine Procedure/Protocol.Low iodine diet.
Lee M, Lee Y, Jeon T, et al.Low iodine diet for one week is sufficient for adequate preparation of high dose radioactive iodine ablation therapy of differentiated thyroid cancer patients in iodine-rich areas.Thyroid. 2014;24(8):1289-96. doi:10.1089/thy.2013.0695
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