Is taking iodine good or bad for Hashimoto’s, and how much is safe to take? There is a lot of debate around this topic, and these are questions I get asked all the time when I speak about thyroid health.

In this article, find out why iodine is so important for thyroid health, three common chemicals that can cause you to be low in iodine, and how I recommend maintaining healthy levels.


The Importance of Iodine in Thyroid Health

As I explain in my book, The Thyroid Connection, iodine and tyrosine are the building blocks of your thyroid hormones. Your thyroid converts tyrosine into thyroglobulin and attaches between one and four iodine atoms to create T1, T2, T3, and T4 respectively. Without enough iodine, your thyroid simply can’t produce its hormones.

The medical community agrees that sufficient levels of iodine are necessary for optimal thyroid function. In fact, the reason we all eat “iodized” salt is because public health experts around the world recognized how important iodine is for preventing thyroid dysfunction.

However, in the past few years there has been quite a bit of controversy over whether Hashimoto’s patients should take supplemental iodine. Some researchers advocate megadoses of iodine, up to a hundred times the recommended daily dose. Although some practitioners and patients have seen success with this method, I do not recommend this for my own patients because extremely high levels of iodine can actually cause both hyperthyroidism and hypothyroidism.1

Conventional physicians, on the other hand, argue against Hashimoto’s patients taking iodine supplements because they believe that if you have Hashimoto’s your system already has too much iodine and that more will only make your condition worse. However, our modern exposure to three key chemicals mean that we aren’t getting as much iodine as we think we are. Let’s look at how those three chemicals can cause you to be low in iodine and how simple lifestyle changes (including moderate iodine supplementation) can help you maintain healthy levels.

Halides and the Risk of Iodine Displacement

Your body is incredibly efficient at absorbing and storing iodine. Unfortunately, your thyroid isn’t perfect at telling the difference between iodine and other substances with very similar chemical structures. Iodine is part of the halogen family, which also includes fluorine, chlorine, and bromine. They all fall into the same column of the periodic table, which, if you can remember back to your high school chemistry days, means they have very similar properties. Fluorine, chlorine, and bromine are similar enough to iodine that your thyroid will suck them up and store them in place of iodine, effectively “displacing” iodine.

Of course, just because these chemicals look like iodine doesn’t mean they can be used to make thyroid hormones. If fluorine, chlorine, and bromine are displacing iodine, your thyroid won’t have enough iodine to produce thyroid hormones, which can lead to hypothyroidism and Hashimoto’s. The higher the concentration of these chemicals that you have in your body, and the lower your iodine levels are, the more likely it is that your thyroid levels will be low and you will experience Hashimoto’s symptoms such as fatigue, brain fog, weight gain, hair loss, and more.

Unfortunately, these three chemicals are now frequently added to our water, foods, and household products, and I believe this is one of the main reasons thyroid disease is now at an epidemic level, with 27 million Americans estimated to suffer from thyroid dysfunction.2


Fluorine, in the form of fluoride, has been added to public water systems in the U.S. since the 1950’s. It was supposedly added to promote dental health, but recent research has shown that fluoride does not actually decrease the risk of cavities in adults at any significant level.3 Furthermore, studies have shown that fluoride is an endocrine disruptor that affects thyroid function and other hormone production glands.4 A recent, large-scale study published earlier this year reported that rates of hypothyroidism in areas that added fluoride to their water system were twice as high compared to areas without added fluoride in their water.5


Like fluoride, chlorine is also added to our water supply, but for its disinfectant abilities. Chlorine is a powerful disinfectant because it works as an oxidizing agent to kill organic molecules. Besides its use in water sanitation, it is the primary ingredient in bleach, and it is used in industrial processes to create plastics, dyes, insecticides, paper products, and other goods.


Bromine is perhaps not as well known as chlorine and fluoride, but it is also highly prevalent as an additive in our foods and household products. Bromine is commonly used in pesticides, plastics, baked goods and flour (commonly labeled as “enriched flour”), citrus-flavored soft drinks, as a sanitizer in hot tubs (where high temperatures make chlorine ineffective), and as a flame retardant in furniture and upholstery.

Those facts might make it seem like constant exposure to these chemicals is unavoidable. But, while it’s true that you probably won’t be able to avoid them entirely, there are a number of simple lifestyle choices you can make to reduce your risk of iodine displacement and help you overcome Hashimoto’s.

How to Maintain Healthy Iodine Levels

Get Plenty of Iodine from your Diet and Supplements

If you maintain sufficient levels of iodine, you significantly reduce your risk of iodine displacement. Sea vegetables and saltwater fish are both naturally rich in iodine, and are a great way to boost dietary iodine levels. I specially designed the 28-day meal plan in The Thyroid Connection to be rich in iodine and the other nutrients needed for optimal thyroid function, and it includes delicious and creative recipes using saltwater fish and sea vegetables. One of my favorites is the Kelp Noodle Stir Fry recipe, and another great option is this week’s recipe for Salmon Burgers.

I also recommend taking a comprehensive multivitamin that contains iodine. While writing my book, I custom formulated a multivitamin that is specially designed for patients with Hashimoto’s and Graves. It contains 300 mcg of iodine, in addition to selenium, zinc, and other key nutrients for thyroid health.

However, as I mentioned, too much iodine can have a negative impact. That’s why I recommend keeping dietary and supplemental iodine intake between 150 and 450mcg daily.

Filter Your Water

You can reduce your chlorine exposure by filtering your water. I use Aquasana filters on all of my taps and showerheads. If you are an avid swimmer or just really enjoy spending time in pools, saltwater pools are a great alternative to chlorinated pools that still allow you to enjoy the summer months. If saltwater pools are not available to you, try to keep your chlorinated pool exposure to a minimum and shower afterward using filtered water.

Avoid Added Fluoride

Fluoride can be found in toothpaste, red and black tea, processed beverages, and some medications, including Cipro. Try switching to this natural, fluoride-free toothpaste and sticking with green tea and filtered water for beverages. If you’re concerned about possible additives in your medications, speak to your pharmacist and find the safest solution that works for you. Always remember to do your research and don’t be afraid to ask questions!

Avoid Flours and Baked Goods

You should already be avoiding gluten-containing breads and baked goods because of gluten’s negative effect on your thyroid, but the added bromine is another reason to skip the pastry aisle. If you’re craving a baked dessert, try this recipe for peachy grain-free cobbler

Go Organic

Since both chlorine and bromine are commonly found in insecticides, your best bet is to choose organic produce and meats. Plus, this will reduce your exposure to toxins that impair thyroid function. If going fully organic isn’t feasible, use the Environmental Working Group’s Dirty Dozen list to prioritize the top 12 foods that you should always buy organic.

Skip the Plastics

Whenever possible, use glass or cloth alternatives to plastic products such as food storage containers and water bottles. This will reduce your exposure to chlorine and bromine, as they are both plastic additives.

Reverse Chronic Illnesses So You Can Take Back Your Health!

Are you ready to beat your symptoms, regain your energy, and feel like yourself again? Whether you have Hashimoto’s, Graves’, or any of the hundreds of other autoimmune diseases, I want you to know you CAN reverse your condition!

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The Autoimmune Solution and The Thyroid Connection - Amy Myers MD