Last Updated on June 5, 2026 by Deliciously Organic Editor
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 didn’t 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.
First need to understand the importance of iodine
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.
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 thyroid in place of iodine and “displace” 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 and impact the thyroid:
- 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.
- When you drink chlorinated water, this not only can destroy healthy flora in the gut, but it can also displace iodine.
- 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.
- Brominated fire retardants used on clothing, carpets, and mattresses can release vapors that are inhaled.
- Brominated vegetable oil is added to some sodas (like Mountain Dew) and can displace iodine.
Here are some steps you can take to protect yourself from chlorine, fluoride and bromine.
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 won’t grab onto chlorine, fluoride or bromine and store it in the thyroid tissues. I personally like to use Iodomere from Standard Process.
If you’ve had issues with iodine in the past or have thyroid issues and have been told iodine isn’t healthy, then click here to read an article I wrote on the topic. I think it will clear up the confusion for you.
For kids, of course, I always 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 the 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 years | 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. Here are some of my favorite water filters at a variety of different price points:
Clearly Filtered pitcher
Radiant Life Countertop Filter (use the code CARRIE to save 10%)
Clearly Filtered under sink filter
Radiant Life Shower Filter (use the code CARRIE to save 10%)
If you can’t purchase any kind of filter for your water right now, it’s a good idea to get 3-4 servings of iodine-rich foods into your diet each week. I really love Dr. Cowen’s sea vegetable powder. You can add it to smoothies, salad dressing, soups, bone broth, etc. to get in an extra dose of iodine.
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, don’t 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.
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/
How can I learn more about the steps I can take for thyroid disease?
I have four fantastic options for you!
- To download my 50 of my top tips to support the thyroid naturally, tap here. I’ll also send you an educational email every few days to help you learn how to support your body naturally.
- If you’d like to learn from first steps you can take to help support your thyroid, check out my class, “5 Keys to Thyroid Hormone Balance”. It’s just 45 minutes and I promise you’ll learn something new!
- If you’re looking for a step-by-step plan for Hashimoto’s that truly works (no more piecing together info!), check out my 90-Day Thyroid Reset Program.
- Book a consult with me for one-on-one help. Here’s info about what working with me looks like.
Thank-you for the helpful, relevant article. 🙂
I have a question about eating seafood/seaweed. My friends all stopped eating anything from the ocean after Fukushima. I kept eating Alaskan salmon, cod, and occasionally seaweeds. I’m the only one with a wonky thyroid out of the group. Is it because I choose to eat seafood that might be contaminated? How can I know for sure that it is safe to continue to eat Pacific ocean foods?
It’s hard to say why your thyroid is off-balance without knowing your full health history. I would say that if it was an issue of iodine being displaced, then drinking chlorinated water, swimming in chlorinated water, drinking fluoridated water, etc. would have much more of an impact than eating some seafood that might or might not be contaminated.
Hi! I have the Lugols 2% iodine, would just doubling it be close enough for the swimming roller? Thanks!
It would be close, but of course, not the exact dosage as written on the chart.
Thank you, very helpful. What about using bleach to dye your hair, like highlights etc.
Does that also affect the Thyroid?
Good point! Yes, this would also negatively effect the thyroid.
I was already well aware of how fluoride in our water negatively affects our thyroid which is why I use a RO filtration system for my drinking water, but I had no idea that chlorine had a similar effect… Thanks for the wake up call!
Is Volvic bottle water ok to drink when you have hyper parathyroid
Thank you for these newsletters, I’m learning more here than anywhere other source. Are these suggestions relevant for someone without a thyroid gland?
Yes. Almost every tissue of the body needs iodine, so taking the steps in this article are very helpful for the health of the entire body.
What about if you get highlights but you ask the hairdresser not to touch your scalp with the bleach . Would the bleach still get into your system and affect your thyroid?
Hello Doctor,
Thank you for your comments
Last week I was about to drown in a swimming pool and as a result I drunk toomuch water. I came out of pool safe in time
But I have noticed swollen thyroid gland elbelow my neck on right side since then. Kindly advise medicine to cure it as soon as possible
Legally, I can’t give personalized advice unless you’re a client. If you’d like to book a consult, give our office, Biodynamic Wellness, a call: 858.259.6000
I have a 15 year old who is a competitive swimmer and spends about 18 hours in the pool a week practicing. Is a supplement something we should be thinking about. And would you go with the Iodemere from Standard Process for his age? Also is it important to get his Thyroid tested first. I know traditional doctors do not always test for all the thyroid factors?
I can’t say for sure, but it’s definitely something I would look into if my child was a swimmer. I would also get a full thyroid panel once a year to check on things. If you need some help with the right steps for your son, give our office, Biodynamic Wellness, a call. 858.259.6000
Hello!
When you say 1 drop of Lugol’s 5% you mean 1 little drop or one drop of the full dispenser? Sorry my English is not very good. Thanks! Very useful article.
One drop. Not a dropper full of liquid.
Which of all these recommendations are ok while breast feeding?
I would ask your practitioner which steps are best for your situation.
Worth reading. Thank you so much!
I am a swimmer almost daily, and dependent on that for physical exercise because of a work related injury 2 years ago. If I don’t swim, I don’t walk, sit or stand well!! Do you think that the seaweed and kelp will counter act any chlorine I may absorb? Also, would applying coconut butter to my skin help protect from the absorption? I eat a lot of tuna, fish, greens, fruits daily but also just found nodules and a goiter and have biopsy done next week. There is so much information out there I do not know which direction to go. If its benign I am not interested in surgery now taking medication. I have always done things naturally. I am at my wits end!
I think the steps I give in the article would be very helpful. I don’t think that coconut oil would be helpful, as it would be difficult to apply to it every single part of the skin.
Hi! What whole house system do you currently recommend? I have looked at Radiant Life, EcoSmarte, ProOne & Aquasana. I also see 2Pure H2O on the Biodynamic site. Do you still recommend Pelican over these? Thanks for all you do! 🙂
I still highly recommend the Pelican for a whole house filtration system. 🙂
Have you heard of taking Taurine?
I just tried to find Pelican Whole house water system. Apparently, Pelican no longer exists. It is now Pentair… AND they had a LOT of complaints against them as Pelican.
I’ll stick with ProOne, as I have their tabletop water filter similar to Berkey, only with 3rd party testing that is genuine, not faked like Berkey did.
Since I’m on a well.and a pitcher isn’t really viable for me due to the amount of water I drink daily.
Clearly filtered told me that their pitchers are for city water only NOT for wells.
I have decided that washing dishes with non filtered water isn’t for me, so I am looking into the whole house water filtration system. Again, I have been well pleased with ProOne and will try theirs.
I have always been a pool swimmer and love it but considering stopping since I do not have access to a chem-free pool. I would love to keep swimming and keep up my iodine supplement, I just don’t know how effective it is if the chlorine is preventing it from being absorbed. Do you know have effective iodine supplementation if I am swimming on a regular basis (2x week)?
So raw milk has more iodine than pasteurized milk? How does that work?
Great info. The link to the Pelican shower filter is not working.
If I have a goiter is there anything I can do to reverse it or help?
I discuss goiter in this article: https://deliciouslyorganic.net/iodine-thyroid-health
I’m confused about the children’s iodine suggestions – one drop of iodine in a rollerball – how long does that last? And isn’t that a super tiny amount divided up over several applications? Don’t we absorb only the amount of iodine that we actually need such that putting a drop on a child’s skin shouldn’t be a problem?
Are you asking how long the roller ball combination lasts? Yes, it’s a very small amount. Yes, we only absorb what we need. And, as always, consult with your practitioner to see what’s best for your child.
I’m on thyroid medication and therefore can’t take iodine as it interferes with my medication (Armour Thyroid) (Was taking NP thyroid, and it was the same)
Most people who are on thyroid meds actually need iodine, and we actually need it for every tissue of the body. I recommend asking your nutritionist what the best solution is for you.
I remember reading this article a really long time ago and there was another link to a different article from a place in California? Do you still have that link?
I’m not sure what you’re referring to.