When Iodine Might Be Bad For Your Thyroid

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Iodine for Thyroid Problems-helpful or harmful
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Iodine is often suggested for people who suspect that they might have problems related to a low thyroid levels. As I’ve recently been (finally) diagnosed with an auto-immune thyroid condition, I’ve been researching this subject a lot lately. I am not a doctor and this is not medical advice, I’m just sharing personal information that was helpful to me….

It turns out, there are times when taking iodine can actually do more harm than good…

Is Iodine Good or Bad for Thyroid?

It depends.

As with any medical condition, there are many variations that fall under the broad category of “thyroid problems” and they must be handled differently.

I found this out the hard way. I had the symptoms of low thyroid for years and from research, knew that iodine could be helpful for thyroid troubles. After much research and at the recommendation of a chiropractor, I started taking iodine and noticed that I felt a lot worse. I figured it might be some kind of adjustment reaction and continued taking it but eventually decided to discontinue it since I didn’t feel any better.

History and research verify my own experience in this…

Data from a number of countries shows that countries who started adding iodine to salt to combat hypothyroidism saw rising rates of autoimmune thyroid problems. Chris Kresser explains:

The following is just a sample of studies around the world demonstrating this effect:

Why does this happen? Because increased intake, especially in supplement form, can increase the autoimmune attack on the thyroid. Iodine reduces the activity of an enzyme called thyroid peroxidase (TPO). TPO is required for proper thyroid hormone production.

The Confounding Factor

In my own treatment plan, I now avoid iodine as my particular type of thyroid problem makes it more harmful that helpful. In fact, some research shows that those with auto-immune thyroid disease will see some benefit just from avoiding iodine.

On the other hand, those with iodine-deficiency induced hypothyroidism can benefit from *careful* supplementation, but given the research showing the increased risk of autoimmune thyroid problems that can result, it is very important to check with a doctor first!

Dr. Paul Jaminet also proposes another factor that affects the iodine/autoimmunity relationship is the presence of selenium:

“Excess intake can cause an autoimmune thyroiditis that bears all the characteristics of Hashimoto’s. However, in animal studies this occurs only if selenium is deficient or in excess. Similarly, in animal studies very high intake can exacerbate a pre-existing autoimmune thyroiditis, but only if selenium is deficient or in excess.

With optimal selenium status, thyroid follicles are healthy, goiter is eliminated, and autoimmune markers like Th1/Th2 ratio and CD4+/CD8+ ratio are normalized over a wide range of iodine intake. It seems that optimizing selenium intake provides powerful protection against autoimmune thyroid disease, and provides tolerance of a wide range of intakes.”

The Bottom Line

I’ll be sharing my own thyroid journey as it unfolds and the protocol I’m using to reverse my symptoms. Anyone who suspects hypothyroidism or thyroid disease should be very careful about supplementation and consider selenium with (or in place of) iodine to see if symptoms improve. Dr. Terry Wahls strongly suggests testing your antibodies periodically to know if they are going up or down if you are making a diet or supplement change, and to be sure to work with the doctor prescribing any thyroid medication to monitor this.

Thyroid disorders (and any hormone-related problems) are complex conditions and it is important to find a good doctor or practitioner who can test the proper thyroid levels and do a thyroid ultrasound to know what the proper treatment plan should be.

This article was medically reviewed by Dr. Terry Wahls, a clinical professor of medicine and clinical research and has published over 60 peer-reviewed scientific abstracts, posters, and papers. As always, this is not personal medical advice and we recommend that you talk with your doctor.

Have you ever struggled with thyroid problems or suspect that you might? What has worked for you? Share below!

Katie Wells Avatar

About Katie Wells

Katie Wells, CTNC, MCHC, Founder of Wellness Mama and Co-founder of Wellnesse, has a background in research, journalism, and nutrition. As a mom of six, she turned to research and took health into her own hands to find answers to her health problems. WellnessMama.com is the culmination of her thousands of hours of research and all posts are medically reviewed and verified by the Wellness Mama research team. Katie is also the author of the bestselling books The Wellness Mama Cookbook and The Wellness Mama 5-Step Lifestyle Detox.


146 responses to “When Iodine Might Be Bad For Your Thyroid”

  1. Jane Avatar

    Have you looked into Magnascent? It seems like a very reputable company with a whole different way of making iodine that seems to be way better for the body to absorb. I just started taking it and would be curious of what you think.

  2. Heather Avatar

    Thanks so much for this post. I’ve been on thyroid medication since 2000, after having my thyroid irradiated in 98 (for hyperactive Graves). Only recently did I start taking iodine at the suggestion of my doctor. My thyroid results have come back normal, but I did feel puffy, so I’m glad I saw this. I have gotten off the iodine to see if I feel any better, and I’m not sure yet. It’s been two weeks. How long did it take you to feel better after getting back off the iodine?

    Oh, and also, do the seaweed snacks I eat with breakfast (or seaweed in sushi) count as problematic? Or is it not enough iodine per serving to worry about?

    Thanks in advance!

    P.S. I’ve been taking selenium for years, as well.

  3. Lindsay Avatar

    I took Lugol’s oil as since returning to the UK from Canada, i have been unable to get treatment for my underactive thyroid (levels are different for assessment). So I took Lugol’s iodine as it is supposed to help with hypothyroid. I put 7lb on in 5 days, all on my stomach and thighs and it would not shift! This is when someone said perhaps i had Hashimoto’s as it can have exactly that effect. It has led me to researching Hashimoto’s and recognising the majority of the symptoms. It also can show up as ‘normal’ range on the T3 and T4 for many years. I will be returning to my doctor armed with a file full of research and hopefully get back on the thyroid meds so I can function. But I won’t be going near iodine again

  4. Lili Avatar

    I found that i was “outside the box” my family members are hashimoto but my thyroidism was brought on by Dr.’s prescription overmedication from a bad accident and my blood tests do not register as Hashi.. I was on Synthroid for 10 years and my Dr. specialist who was also thyroid said, if i didn’t feel right on 50mcg. to take more in tiny increments, break up the pills so I did, he also prescribed pills in 250mcg. that was easier to cut up and also less expensive to buy because I got more doses per pill. Then I REALLY started to feel better, and more in control keeping journal and paying attention to my body, my tests became better and I settled on a 0 TSH at 250mcg. daily for a year, .01 was painful for me and 0 was perfect, no pain or symptoms. At 0 TSH with synthroid after 18 mos. I started getting stomach irritation in the mornings and decided to go off synthroid altogether and go natural. Using natural dessicated thyroid daily for 4 years since and am feeling great every day with one in the morning, but sometimes I feel better when taking in the afternoon around 2pm with food. Sharp mind and body. When sick, If I ever get sick anymore I use mycelia supplements with cordyceps daily for energy and when my mind feels droll or sluggish I may take additional desiccated thyroid for a few days and if sick I may take 2 a day for a few days and illness goes away. Something to note is that when we travel and/or the weather was up over 85 degrees daily I started to get much too hot and felt I was having Thyroid Surges, so during the extreme hot summer months usually July-Sept. in Calif. I just don’t take any thyroid meds at all, but make sure I get proper dietary allowances of all vitamins and minerals expecially magnesium 250-500 taken daily and I don’t get the surges. Magnesium and Selenium really help, and also helps in times of constipation, but should note that taking a Potassium Chloride or Pot. Gluc. can help keep your thyroid on track. If you’re taking diuretics also make sure you get a potassium and magnesium supplement because Dr.’s FORGET to tell you this gets dangerously depleted when they offer HZTZ diuretics for bloat in thyroid conditions. We found that a 1T. Epsom Salt to 2c. water hair rinse after washing stops hair loss. Always take a Magnesium supplement daily and feel great, gotta love that magnesium, the body doesn’t work without it! Hope this all makes sense, it’s all just a crap shoot you MUST just listen to your body and TUNE IN. Knowledge is Power!

  5. Marta Avatar

    Unfortunately iodized salt is unhealthy beacuse of the processing and other ingredients which prevent iodine absorption. The best source of iodine is Lugol’s. It’s also very important to take selenium when takig iodine and the best is starting to take it at leat 1 month before. I have Hashimoto’s and I was told iodine is bad for me so I believed it. I struggled for 10 years trying everything from diets and supplements. Nothing would help. Iodine with selenium, vit D3K7, Vit C, complex B gave me my health back. The iodized salt is just another scam!

  6. Lili Avatar

    I took iodoral. One pill on weekdays for several weeks. I was diagnosed subclinical hypothyroid some years ago . My thyroid start hurting (both sides are a little swollen) and I start to become very sensitive to heat and become very anxious when I had caffeine products and my hands and feet felt numb and tingly . I saw online an Endocrine physician said that high potency iodone can bring on the symptoms of hyperthyroidism. He told of a woman with similar symptoms to use the exact same product as me. I stopped Iodoral snd I’ve been wondering what I can do to feel better and selenium might just be what I need. Thanks for your article. I wrote the company that makes Iodoral and I’m waiting to see what they have to say.

  7. Batrice Avatar

    Hi Katie! What’s your take on the safety of pregnancy while restricting iodine supplementation with Hashiomotos-I know iodine is critical for a successful pregnancy. Thanks!

  8. Lauren Graves Avatar
    Lauren Graves

    With the understanding that protocols for autoimmune thyroid issues such as Hashimotos and Graves would NOTbe the same as those with hypothyroid, etc., what of transdermal vs oral supplementation? I am curious as to the accounts of oral supplementation ( dropping Lugols in tea & coffee) when i assume that not all used nonfluoridated water. Some say fluoride and iodine neutralize one another. Do you know that to be true, Katie? Also, are all forms (Lugols, nascent, etc) of supplemental iodine synthetic? I appreciate the conversation here….much love to all trying to find the healthiest approach.

    1. Katie - Wellness Mama Avatar

      I would personally consider transdermal safer because it would be a little more difficult to get too much. Iodine need definitely seems to vary from person to person so I’d suggest working with a qualified doctor or practitioner to make sure you’re getting the right amount for you. Experts like Dr. Izabella Wentz and Dr. Alan Christianson estimate that as much as 90% of hypothyroid cases are Hashimotos, which makes me question the common recommendation for iodine in those with hypothyroidism, as many of these people may have Hashimotos and not even know it.

  9. Mary A. Avatar

    I haven’t read all the comments so this suggestion may have already been mentioned, but you need to read Dr. David Brownstein’s books about iodine and how we absolutely need it and can’t live without it. Most people have low iodine levels, even children, it’s a simple fact of life these days and he goes into great detail. He also details how supporting minerals and vitamins are needed for our thyroid health. And, remember, iodine is used by every cell in the human body, not just the thyroid. The breasts, ovaries, prostate, and salivary glands also use a lot of iodine. Supplementing with iodine is absolutely crucial for some people, myself included. I suffer from a slight goiter and supplementing with iodine is the only thing that has helped.

  10. Candice Avatar

    Hi there! Cant beleive I found this post! I just came back from my annual physical and my Doc says I have Low T3, High LDL and Triglycerides, and low HDL. Im being sent to the Endo next week, and an ultrasound as well. I have NEVER had levels like this before, so I’m a little worried. Also, I was hoping for better than usual results becasue Ive been eating almost 100 percent Vegan for the past 4 months! The Doc wanted me to start taking cholesterol meds asap, but I asked to hold off on that for a few months so I can try to figure out if I can modify something in my life, (diet, suppliments, exercise, etc.), to change these numbers for the better.
    So, thank you, for writing about your experience, and sharing those experiences with us. Good luck to you. 🙂

  11. Kay Avatar

    Selenium helps remove an iodine atom from the T4 to convert it to T3, which is essential in thyroid health and in order to active your metabolism. If you are boosting iodine intake without selenium, you could be in trouble. Iodine and selenium have a symbiotic relationship when it comes to your thyroid health. Don’t sell yourself short on a synthetic selenium product either – use a broad spectrum, high selenium yeast product. This article gives a very manageable overview of the iodine-selenium relationship: https://www.healthandscience.eu/index.php?option=com_content&view=article&id=738:selenium-and-iodine-make-a-strong-team-but-are-you-getting-enough-us&lang=us

  12. Jennifer Avatar

    Without going into great detail, I have had issues with my thyroid for several years. Within in 3 months of going off of gluten my numbers went back into the normal range. But I have never felt the same as before and still 30 pounds heavier. I tried taking kelp supplements from two different reliable sources. Both made me feel anxious, irritable and easily angered, that it scared me.
    But recently I have incorporated Cod into my diet, eating it most days of the week. And all of a sudden it felt like my thyroid was alive again. I began to feel incredible like myself again, my mood was fantastic and I felt as though I had my old self energy returning.

    What could be the difference in kelp supplements and eating Cod?

    My reaction to kelp, could it have been too much iodine? (I tired holding the dosage, and still made me feel that way.)

    The way my body is processing the iodine in the cod, I want to find a supplement similar. Any ideas? I am craving this responsibly sourced cod fish everyday!!

    Any other ideas, please feel free to share. Thank you to whomever responds. 🙂

  13. Bob Ives Avatar
    Bob Ives

    Having RA, GWI and Hashimoto’s, I find this an interesting post. I’m not sure exactly what I believe about iodine supplementation at the moment. However, I have almost completely kicked RA to the curb by addressing the cause with antibacterials, probiotics and immune building supplements and foods (No crazy diet changes however). I further believe that Hashimoto came into play due to my primary bacterial (Mycoplasma) infection and am hoping that as I clear it out, it will also, over time, repair my thyroid. I am currently supplementing with a thyroid supplement (That does contain selenium and iodine) as well as with a drop of Nascent Iodine daily. Currently, I feel absolutely great.

    Good luck to you all.

  14. Andy Avatar

    What if you’ve had a Total Thyroidectomy? Would iodine be harmful then? The same for L-Tyrosine?

  15. Bettie Avatar

    Diagnosed with Graves Disease and subsequently having RAI treatment, the Dr. told me NOT to eat anything with iodine in it! No junk food because all contained SALT WITH IODINE. Even ketsup! to be wary of food at a restaurant and to order according to diet needs. Best still to eat homecooked meals. Not to eat any kind of shell fish or seaweed products. I am contantly shocked to find that on the sites that say they are soooo healthy still have recipes for seaweed, kelp or nori wraps and etc. Of course, I know that making a nice sushi style treat can be done riceless with veggies AND wrapped with a of a slice of cucumber. But why don’t more people seem to be aware of this aggravation to the thyroid or the lack of one but still with the antibodies present in system. Also, thank you Katie, for the WP thyroid suggestion! I finally talked my Dr. into this since Armour had gotten more expensive and has more fillers. I feel so much better!

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