Low-Iodine Diet: Here Are The Foods You Should Avoid

Are you receiving radioactive iodine therapy? Has your doctor told you to follow a low-iodine diet? Our registered dietitian, Sarah Wilcox shares the importance of following a low-iodine diet before therapy and the foods you should avoid when on the diet.

A low-iodine diet is a diet with less than 50 micrograms of iodine per day. It is generally for patients who are receiving radioactive iodine treatment for thyroid disease or cancer. In preparation for your treatment, your doctor will have you follow a low-iodine diet.

A low-iodine diet should be short-term, usually 1-2 weeks prior to you receiving your treatment, and works to make sure that the therapy is effective. Once the radioactive iodine therapy is complete, most people stop following the diet.

When you are on a low-iodine diet, there are certain foods that you should avoid as some of the foods increase your absorption of iodine or contains iodine.

Here are a list of supplements and foods that you should avoid:


Supplements containing iodine (often hair supplements or women’s supplements), ingredients may say seaweed, iodine, iodate, sodium iodide, potassium iodide.  Supplements include bars, drinks, and multivitamins or pills meant to supplement the intake of actual foods.


  • Seaweed (kelp, nori, kombu, wakame)
  • Fish
  • Egg yolk or whole egg
  • Dairy products (milk, yogurt, cheese, ice cream made from milk or containing high iodine ingredients)
  • Commercially prepared bread or pasta that lists ingredients such as iodate, potassium iodide, potassium iodate, or large amounts of iodized salts.
  • Iodized salt
  • Canned foods with added salt
  • Sushi
  • Liver
  • Shellfish
  • Pasta made in salted water or with the above-listed ingredients
  • Boxed cereals or instant oats
  • Fast foods
  • Frozen meals
  • Chips and crackers with iodized salt or added iodine ingredients listed above. If ingredients say “salt” or “sodium chloride” it may be beneficial to avoid.

Fresh fruits and vegetables

Iodine Reduction Tips

  • Substitute seafood for chicken or beef in recipes
  • Increase fruits and vegetables (these are typically a low source of iodine unless they have added iodine ingredients). Fresh fruits and vegetables are the best, but buy frozen without added seasoning second.
  • Meat is okay but avoid jerky. Meat like chicken or beef can be a good choice in moderation. Meat has small amounts of iodine naturally so limit yourself to 3-ounce portions, 3 times a day.
  • Egg whites can help get extra protein and nutrients.
  • Oatmeal is great if it is not instant
  • Salt-free crackers and unsalted rice cakes
  • Unsalted nuts
  • Almond milk and cashew milk but be sure to read labels first. You can also try yogurt made from almond or cashew milk.
  • Baked goods made at home with egg whites and non-iodized salt that are dairy-free
  • Oils
  • Coffee or tea
  • Water
  • Fruit juices or smoothies
  • All fresh or dried herbs not containing salt, sodium chloride, iodine ingredients, or potassium chloride

If you have more questions about the foods that you should avoid eating while on your low-iodine diet, consult with a registered dietitian or any other health professional. Be sure to check out our blog, for more healthy lifestyle content.

Be Well. Eat Well.

Sarah Wilcox MS RS LD