Thyroid Cancer Diagnosis Diet

After surgery for certain types of thyroid cancer, radioactive iodine (RAI) is used to destroy any remaining and possibly cancerous thyroid cells. (RAI is not used for medullary or anaplastic thyroid cancers). Also, as part of regular checkups, thyroid cancer patients receive RAI to scan their bodies for recurring cancer. Prior to any RAI treatment, thyroid cancer patients will need to go on a low iodine diet.

While not exactly a “thyroid cancer diet,” limiting your diet to low iodine foods will help your treatment proceed effectively. With a low iodine diet, your body depletes its stores of iodine. Then, when you receive treatment with radioactive iodine, your thyroid cells are particularly primed to absorb the iodine, which makes the treatment more effective.

Thyroid Diet Variations

While it’s common for physicians to recommend low iodine foods prior to RAI treatment, the duration and strictness of the suggested low iodine diets varies.

Some physicians restrict patients to low iodine foods for as long as two weeks prior to treatment, and others put patients on the “thyroid cancer diet” for just a few days.

Just how low is a low iodine diet? That varies. One teaspoon of iodized salt contains 400 micrograms (mcg) of iodine and the recommended daily allowance (RDA) of iodine for adults is 150 mcg. The American Thyroid Association suggests patients on low iodine diets limit consumption to fewer than 50 mcg a day. Other physicians advise keeping iodine consumption down to 80-100 mcg a day.

Talk with your doctor to make sure you understand the thyroid diet recommendations you should follow.

Diet of Low Iodine — Foods to Avoid

Some foods are definitely to be avoided when you’re limiting your iodine consumption. These include:

  • Breads made with iodate dough conditioners
  • Chocolate
  • Cured foods like ham, lox, corned beef and sauerkraut
  • Eggs
  • Iodized salt or sea salt
  • Milk, cheese, yogurt or any dairy products
  • Molasses
  • Red dye #3 (not all red dyes contain iodine, but it may be difficult to determine which dye is in a product)
  • Seafood
  • Tofu and other soy products
  • Vitamins with iodine.

Many medical professionals advise patients dealing with thyroid cancer on diet restrictions to avoid eating out, because it’s so hard to know what’s in the food. In addition, since a low iodine diet prohibits dairy products, some recommend calcium supplements. Discuss restrictions with your healthcare provider.

Low Iodine Recipes

You may be wondering if you can eat anything on a low iodine diet. Fortunately, you can find many sources of low iodine recipes. The Thyroid Cancer Survivor’s Association and other support groups offer low iodine recipes and low iodine cookbooks to show you how follow a low iodine diet. For example, you can learn how to make milk out of almonds for use in coffee or baking.


Thyroid Cancer Survivor’s Association Staff. (n.d.). The low-iodine diet. Retrieved March 18, 2010, from the Thyroid Cancer Survivor’s Association Web site:

Shomon, M. (2003). The low iodine diet. Retrieved March 22, 2010, from the Web site:

Gilletz. N. (2005). The low iodine diet cookbook. Your Health Press.

Claghorn, K. (2001). Low iodine diet. Retrieved March 22, 2010, from the Abramson Cancer Center of the University of Pennsylvania Web site: