Iodine During Pregnancy Is More Important Than Thyroid Hormone for Your Child’s Brain Development

If you have thyroid autoimmunity (aka Hashimoto’s or Graves’), high iodine intake can make your condition worse. But what do you do if you have Hashimoto’s and are pregnant? A recent study provides an answer for mothers that will ensure their child’s brain develops optimally.

If you have questions about managing your autoimmunity or iodine intake, click here.

Iodine During Pregnancy Is More Important Than Thyroid Hormone for Your Child’s Brain Development

Dr. Michael Ruscio: Hi. This is Dr. Ruscio. And let’s discuss a very interesting study Trusted SourcePubMedGo to source than can help guide mothers on the appropriate nutritional strategy to make sure that their developing child has the best brain or neurological development. Here is a recent study. I’ll put the abstract up here on the screen.

And I’ll quote from the authors here. “Neurointellectual outcomes,” meaning brain development essentially, “in children appear to be more dependent on their mothers’ nutritional iodine status than on maternal thyroid function.”

And more specifically, what this study looked at was iodine supplementation compared to thyroid hormone replacement—so looking at what kind of brain development we had in children from mothers who were taking iodine compared to mothers who were taking thyroid hormone, and also looked at urinary levels of iodine in mom compared to thyroid hormone levels in mom and how that correlated to the child’s brain development.

And what was found consistently was that the iodine status was more important than either taking thyroid hormone or having higher levels of thyroid hormone. So again, in short, iodine—more important for the development of the child’s brain than thyroid hormone levels or thyroid hormone replacement.

Why this is relevant is because if you have hypothyroid, the most common cause of hypothyroidism is thyroid autoimmunity. And iodine has been consistently shown to make thyroid autoimmunity worse when iodine intake is high. So it would not be an unreasonable thought for a mother to be recommended to—a mother who has Hashimoto’s thyroid autoimmunity as the cause of her hypothyroid to avoid iodine so as not to make the thyroid autoimmunity worse.

However, this study shows that it would be a good idea to make sure mom has adequate iodine status and maybe even consider supplementing with iodine because of the effect on the child.

Now, the other good news here is that selenium may help buffer any of the autoimmune-provoking impact that can be begotten from iodine. And so by using iodine with selenium, we will hopefully be able to have all the brain impact from iodine but safeguard as much as possible against any of the autoimmune potential from iodine by using the selenium.

So again, this study shows that as a mom, it’s important that you have good iodine status for the brain development of your child. And I would suggest that you make the iodine more important than the thyroid autoimmunity in this case because, as this study shows, if you avoid iodine, yes, you may help with your thyroid autoimmunity. But as these study results show, having better iodine status is going to be better for the development of your child’s brain.

So if you’re pregnant and you want to make sure your child has good brain development, do not avoid iodine. Make sure you have adequate iodine intake. That will be more important for the health of your child’s brain than even taking thyroid hormone replacement. Not to say that you shouldn’t take thyroid hormone replacement if you need it, but iodine is going to be more important for the intellectual or neurological development of your child than would thyroid hormone replacement.

So this is Dr. Ruscio. And I hope this information helps you get healthy and get back to your life. Thanks.

If you have questions about managing your autoimmunity or iodine intake, click here.

What do you think? I would like to hear your thoughts or experience with this.

Discussion

I care about answering your questions and sharing my knowledge with you. Leave a comment or connect with me on social media asking any health question you may have and I just might incorporate it into our next listener questions podcast episode just for you!

20 thoughts on “Iodine During Pregnancy Is More Important Than Thyroid Hormone for Your Child’s Brain Development

  1. Let’s not forget that thyroid medications themselves contain iodine. Don’t remember off the top of my head about levothyroxine but 1 grain of NDT contains something like 120mcg of iodine. Can and should be taken into account!

    1. Hi Daria,
      Good points and thanks for sharing. However, according to this studies results the iodine in the thyroid hormone didn’t seem to be enough to have an effect. It was only those who used iodized salt who experience the cognitive benefits in their offspring.

  2. Let’s not forget that thyroid medications themselves contain iodine. Don’t remember off the top of my head about levothyroxine but 1 grain of NDT contains something like 120mcg of iodine. Can and should be taken into account!

    1. Hi Daria,
      Good points and thanks for sharing. However, according to this studies results the iodine in the thyroid hormone didn’t seem to be enough to have an effect. It was only those who used iodized salt who experience the cognitive benefits in their offspring.

  3. Thanks for this article. I am in a similar situation. After a miscarriage and a course of Trimethoprim antibiotics for Uti my health really deteriorated. I started getting what I now believe may have been hyperthyroid attacks, or possibly I developed an allergy to seaweed which gave me symptoms that resembled hyperthyroid: shaking at night, eyes wanted to stay open, I couldn’t keep still in bed or sometimes during the day time when sitting I was compelled to walk around, exhaustion in afternoon/evening. One day I stopped taking Seagreens seaweed supplement and all these symptoms stopped until a few months later when I ate a few nori sheets. That night my symptoms returned, including racing heart. I linked it to the seaweed. I do believe it has something to do with the antibiotics causing leaky gut.
    I stopped eating seaweed.
    A few months later I took a full thyroid panel as I was worried I may have developed autoimmune thyroid but I was told I have perfect results which is great but I worry if I was to eat seaweed or iodine supplement again, perhaps my tsh would drop down suddenly. I believe it’s possible this is what was happening.
    My results: T4 71, TSH 1.32, FT4 14.8, FT3 4.3, ratio 3.4, rT3 0.28. TG <20, TPO <10.
    I&#039m not sure what to do next. It&#039s been 6 months since I touched seaweed and have not had any of those scary symptoms. I do want to try for another baby one day but worried unless I figure out what was wrong and I want to manage to tolerate seaweed or iodine (never taken an iodine supplement before except in a multi years ago) again. Do you know what could be going on?
    I think possibly one day I should try iodine or seaweed alongside selenium and wait for any return of symptoms. Perhaps I&#039m deficient in selenium.
    Any suggestions greatly appreciated as I feel I am in limbo. My GP is clueless and thinks it&#039s all anxiety. So I&#039ve been trying to figure things out myself with private tests and lots of reading.

    P. S. Previously I used to take Seagreens seaweed or eat sushi without a problem for years even during a healthy pregnancy.

    1. Hi Claire,
      We have done a few previous posts on iodine that might be very helpful here, search iodine in our search box for more. Also, you might want to reach out to Dr. Jolene Brighten, who was on the podcast a number of months ago as this is her area of specialty. Hope this helps!

  4. Thanks for this article. I am in a similar situation. After a miscarriage and a course of Trimethoprim antibiotics for Uti my health really deteriorated. I started getting what I now believe may have been hyperthyroid attacks, or possibly I developed an allergy to seaweed which gave me symptoms that resembled hyperthyroid: shaking at night, eyes wanted to stay open, I couldn’t keep still in bed or sometimes during the day time when sitting I was compelled to walk around, exhaustion in afternoon/evening. One day I stopped taking Seagreens seaweed supplement and all these symptoms stopped until a few months later when I ate a few nori sheets. That night my symptoms returned, including racing heart. I linked it to the seaweed. I do believe it has something to do with the antibiotics causing leaky gut.
    I stopped eating seaweed.
    A few months later I took a full thyroid panel as I was worried I may have developed autoimmune thyroid but I was told I have perfect results which is great but I worry if I was to eat seaweed or iodine supplement again, perhaps my tsh would drop down suddenly. I believe it’s possible this is what was happening.
    My results: T4 71, TSH 1.32, FT4 14.8, FT3 4.3, ratio 3.4, rT3 0.28. TG <20, TPO <10.
    I'm not sure what to do next. It's been 6 months since I touched seaweed and have not had any of those scary symptoms. I do want to try for another baby one day but worried unless I figure out what was wrong and I want to manage to tolerate seaweed or iodine (never taken an iodine supplement before except in a multi years ago) again. Do you know what could be going on?
    I think possibly one day I should try iodine or seaweed alongside selenium and wait for any return of symptoms. Perhaps I'm deficient in selenium.
    Any suggestions greatly appreciated as I feel I am in limbo. My GP is clueless and thinks it's all anxiety. So I've been trying to figure things out myself with private tests and lots of reading.

    P. S. Previously I used to take Seagreens seaweed or eat sushi without a problem for years even during a healthy pregnancy.

    1. Hi Claire,
      We have done a few previous posts on iodine that might be very helpful here, search iodine in our search box for more. Also, you might want to reach out to Dr. Jolene Brighten, who was on the podcast a number of months ago as this is her area of specialty. Hope this helps!

  5. Hi Dr. Ruscio,
    Is there a specific gestational period where iodine supplementation is beneficial? Is it too late to start towards the third trimester?

      1. Hi Drew,
        Thank you for responding, however having revisited the article I can’t find any information on the implications of iodine supplementation towards the last trimester?

        1. Hi Marie,

          I checked in with Dr R and he doesn’t specialize in pregnancy, so isn’t sure about the third trimester specifically. Sorry we can’t be of more help!

  6. Hi Dr. Ruscio,
    Is there a specific gestational period where iodine supplementation is beneficial? Is it too late to start towards the third trimester?

      1. Hi Drew,
        Thank you for responding, however having revisited the article I can’t find any information on the implications of iodine supplementation towards the last trimester?

        1. Hi Marie,

          I checked in with Dr R and he doesn’t specialize in pregnancy, so isn’t sure about the third trimester specifically. Sorry we can’t be of more help!

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