Last Updated on April 14, 2025 by Carrie Korem, FNTP
Did you know that chlorine found in swimming pools and tap water, fluoride found in tap water and toothpaste and bromide found in baked goods can have a negative affect on the thyroid? I did a quick post on this over on Instagram the other day and didnโt realize it would be such a hot topic, so I thought it would be a good idea to write out some more details so we can all understand how to take the proper steps to protect the thyroid.
Before I get into the details, we first need to understand the importance of iodine.ย
Iodine and tyrosine are critical for the production of thyroid hormones. When your body sees iodine, it snatches it up and stores it in the thyroid for later use. However, your thyroid has a hard time telling the difference between iodine and other substances that have similar chemical structures.ย
This is where chlorine, fluorine, and bromine come into play.
Chlorine, fluorine, bromine and iodine are all halogens. Unfortunately, chlorine, fluorine and bromine are similar enough to iodine that they can be absorbed by the thyroidย in place of iodine and โdisplaceโ the iodine.
The mechanism behind “halogen displacement” was probably best described by J.C. Jarvis, M.D., who wrote: “The clinical activity of any one of these four halogens is in inverse proportion to its atomic weight. This means that any one of the four can displace the element with a higher atomic weight, but cannot displace an element with a lower atomic weight. For example, fluorine can displace chlorine, bromine and iodine because fluorine has a lower atomic weight than the other three. Similarly, chlorine can displace bromine and iodine because they both have a higher atomic weight. Likewise, bromine can displace iodine from the body because iodine has a higher atomic weight.” (Meaning – all of the other halides replace iodine.)
If these other chemicals displace iodine, then your thyroid won’t be able to produce the proper amount of thyroid hormone needed for your body, leading to low thyroid levels, hypothyroidism and possibly goiter, nodules and cysts.
Here are ways iodine can be displaced each day:
- When you swim in a swimming pool, or bathe in chlorinated water, the skin soaks up the chlorine and can displace the iodine leading to low thyroid hormone levels.ย
- When you drink chlorinated water, this not only can destroy healthy flora in the gut, but it can also displace iodine.ย
- When you drink fluoridated water, the fluoride can displace the iodine.
- Eating baked goods and pasta with potassium bromate added to the flour can displace the iodine as well.ย
- Brominated fire retardants used on clothing, carpets, and mattresses can release vapors that are inhaled.ย
- Brominated vegetable oil is added to some sodas (like Mountain Dew) and can displace iodine.
Now, I know this can be overwhelming. Justย remember, itโs all about baby steps! So, here are some steps you can take to start moving in the right direction:
1. If you swim in a chlorinated pool, I recommend taking an iodine supplement or eating a healthy serving of iodine-rich foods, such as sea vegetables, eggs, raw milk or whole yogurt to provide the body with enough iodine so that the thyroid wonโt grab onto chlorine, fluoride or bromine and store it in the thyroid tissues.ย I personally like to use Iodomere fromย Standard Process. For kids, of course, I alwaysย recommend getting iodine from foods, but if you’re traveling, or if you need an easy way to help your little ones get the additional iodine needed after swimming, I recommend making a roller ball blend with liquid Lugol’s iodine 5% and fractionated coconut oil. Here is theย recommended dosage:
| Birth to 12 months | 1 drop of Lugol’s Iodine 5% in 7 ml of fractionated coconut oil in a glass roller ball |
Shake and then rub 1 swipe on the inner arm |
| 1-3 years | 1 drop of Lugol’s Iodine 5% in 6.5 ml of fractionated coconut oil in a glass roller ball |
Shake and then rub 1 swipe on the inner arm |
| 3-5 yearsย | 1 drop of Lugol’s Iodine 5% in 6ml of fractionated coconut oil in a glass roller ball |
Shake and then rub 1 swipe on the inner arm |
| 5 years and up | 2 drops of Lugol’s Iodine 5% in 10 ml fractionated coconut oil in a glass roller ball |
Shake and then rub 1 swipe on the inner arm |
2. Filter your water.ย Here are some of my favorite water filters at a variety of different price points:
Clearly Filtered pitcherย
Radiant Life Countertop Filter (use the code CARRIE to save 10%)
Clearly Filtered under sink filter
Greenfield whole house filtration system โ they also have replacement filters that you can use in your Berkey water filter (use the code ORGANIC10 to save 10%)
Radiant Life Shower Filter (use the code CARRIE to save 10%)
3. Avoid using bromated flour or flour that contains potassium bromate. Keep in mind, pastas and baked goods can contain this kind of flour as well. In 1982, researchers in Japan published a series of studies showing that potassium bromate causes cancer in the thyroid in rats and mice. Potassium bromate is illegal in the EU, Canada and Brazil, but is still allowed here in the US.
4. To reduce your exposure to fire retardants, donโt purchase clothing that is sprayed with them, wash all clothing before wearing and, if possible, choose mattresses and carpets that are free of fire-retardants.
If you canโt purchase any kind of filter for your water right now, itโs a good idea to get 3-4 servings of iodine-rich foods into your diet each week. I really love Dr. Cowenโs sea vegetable powder. You can add it to smoothies, salad dressing, soups, bone broth, etc. to get in an extra dose of iodine.ย
Hereโs a list of iodine-rich foods:
Wild Sea Vegetables – such as seaweed and dried kelp
Wild Seafood – such as cod or tuna
Raw Milk or Grass-Fed Yogurt
Pastured Eggs
If youโve had issues with iodine in the past or have thyroid issues and have been told iodine isnโt healthy, then click here to read an article I wrote on the topic. I think it will clear up the confusion for you.ย
For further reading:
Interaction of bromine with iodine in the rat thyroid gland at enhanced bromide intake
Effects of the Environment, Chemicals and Drugs on Thyroid Function
Iodine: Why You Need It, Why You Can’t Live Without It by Dr. Brownstein
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3890436/
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