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Low-Iodine Diet

A low-iodine diet contains less than 50 micrograms (mcg) of iodine per day.

Iodine is a mineral. It plays an important role in several processes that take place in your body. One role is the production of a hormone called thyroxine in the thyroid gland.

Iodine is found naturally in certain foods, but most of it comes from iodized salt, dairy products, and breads. Adults need 150 mcg of iodine a day.

You will need to follow a low-iodine diet to increase the effectiveness of your upcoming radioactive iodine therapy. If you have iodine in your diet, it can prevent your thyroid from taking up the radioactive iodine. Your doctor may put you on a low-iodine diet 1 or 2 weeks before you get your dose of radioactive iodine. Follow this diet until your test or treatment is complete.

This diet does not meet the suggested daily allowance for all nutrients. You will only be on it for a short time. Your doctor will tell you when to begin and when to stop this diet.

Foods, Beverages, and Other Items Containing Iodine

Read all food labels to check for iodine content. Do not eat or use:

Iodized salt

Sea salt in any form

Seasoning mixes made with salt, such as adobo

Onion salt

Celery salt

Garlic salt

Seasoned salt

Seaweed (kelp, nori, kombu, wakame)

Any food that has

Iodates

Iodides

Algin

Alginates

Carrageen

Agar

Commercial breads and bakery products

Milk (except for 1 ounce a day) and milk products, such as cheese, yogurt, and cream

Egg yolks

Most seafood (except fresh-water fish)

Vitamins and food supplements, if they have iodine. If you are not sure about the iodine content, do not take them.

Food, pills, or capsules with food dyes that are orange, red, or brown in color. Examples include red or pink cereals or candies.

Antiseptics, such as iodine (Betadine®) applied on a cut

Cough medications (especially those with red coloring)

Liquid nutritional supplements and commercial shakes, such as:

Ensure®

Boost®

Nutrament®

Restaurant and processed foods

Soy products, such as edamame, tofu, soy burgers (e.g., Boca®), etc.

All canned foods. The lining of the can contains iodine.

If you are receiving tube feeding formula, ask your dietitian or doctor what to do.

Low-Iodine Diet Guidelines

Drink plenty of liquids

Unless your doctor gives you other instructions, you must drink at least 8 to 10 (8-ounce) cups of liquid a day. This includes the drinks listed in the diet guidelines below and as much water as you want.

Frequently Asked Questions

How do I know if a certain food has iodine?

The iodine content of many foods is not known, which can seem confusing. Remember, this is a low-iodine diet and not a noniodine diet. We encourage you to follow our list of recommended foods as a guide and to call your dietitian with any questions.

If a product label says it has sodium, does that mean it also has iodine?

Not necessarily. Sodium and iodine are not the same thing. However, avoid products that list salt as an ingredient because the salt may contain iodine.

I have read dietary guidelines for a low-iodine diet on the Internet that are different than what is discussed here. Which should I follow?

We encourage you to follow our list of recommended foods and foods to avoid. This is because the iodine content of many foods is not known and not all Internet sources are accurate.

Can I use kosher salt?

We recommend using only noniodized salt and only in small quantities because it may still contain a small amount of iodine. If you need salt, choose Morton’s® Plain Table Salt and use sparingly.

My doctor told me to suck on hard candy for dry mouth but this diet says I can’t have candy. Which instructions should I follow?

We encourage you to avoid candy because there are many ingredients that may contain iodine in unknown amounts. If you need candy, choose GoNaturallyTM Organic Honey Lemon hard candies for dry mouth.

Should I stop taking any of my medications?

Do not stop taking any of your medications unless your doctor tells you to do so. Call your doctor or nurse if you have any questions about your medications.

Also, tell your doctor about any vitamins or supplements that you are taking. You will need to stop taking them if they contain iodine. If you are not sure about the iodine content, do not take them. Because vitamins and supplements are not regulated in the same way other medications are, it may be difficult to tell if they contain iodine.

Contact Information

If you have any questions or concerns, talk with a member of your healthcare team. You can reach them Monday through Friday from 9:00 am to 5:00 pm at ____________________. After 5:00 pm, during the weekend, and on holidays, please call____________________. If there’s no number listed, or you’re not sure, call 212-639-2000.