Your Thyroid + Iodine, Part 2

This post is the fifth installment in my ten-part Minerals and Your Thyroid series, where I’m highlighting eight thyroid-supportive minerals (iodine is two parts) and one troublemaker: fluoride.

Prior posts: Calcium, Copper, Iron, Iodine (Part 1)

Iodine symbol: I
Atomic number: 53

As I said in Part 1 of this 2-part ‘Your Thyroid + Iodine’ miniseries, I have yet to find a more wildly-challenged and wildly-supported health topic than whether those with hypothyroidism and Hashimoto’s should supplement with iodine.

And if you do choose to supplement with it – how to do it.

Again, I don’t have the final word on iodine. I’ve simply done my best to outline both sides of this hotly-debated story.

As you’ll continue to discover in Part 2, many esteemed and respected doctors are on different sides of this controversy – including many I haven’t quoted or referenced.

To review, in Part 1, we covered:

  • The iodine/thyroid relationship
  • The difference between Hashimoto’s and non-autoimmune hypothyroidism (the latter often a result of iodine deficiency)
  • Causes of iodine deficiency
  • Comparing deficiency in the U.S. to other parts of the world
  • The purported iodine/“goitrogen” relationship
  • Looking back at the last five years of claims in the functional medicine community
  • Why some feel terribly on iodine supplementation
  • The role of iodine related to other tissues, especially breast health
  • One critical factor in tolerating (or not) iodine supplementation
  • How iodine gets “displaced”
  • The role of sea vegetables and seafood

Let’s get on with Part 2, shall we?

The Dose Makes the Poison?
In June of 2013, The American Thyroid Association (ATA) published a statement warning about the risks of iodine overconsumption, especially from iodine, potassium iodide, and kelp supplements. (More on kelp later.)

They advised against taking more than 500 micrograms (note that this is micrograms, not milligrams) of iodine daily and stated that ingesting more than 1,100 micrograms per day could cause thyroid dysfunction.

This study from The American Journal of Clinical Nutrition showed that taking relatively higher doses of iodine – 400 micrograms daily or more – ironically lead to hypothyroidism.

Dr. Richard Shames states, “Iodine is a double-edged sword for thyroid sufferers. More than adequate amounts may further irritate and inflame an already ailing thyroid gland.”

Dr. Alan Christianson states, “Adequate iodine is especially important, but it is essential not to take too much. Iodine is one of the nutrients you can get too little or too much of, both impacting proper thyroid function. Most iodine supplements have too high of a dosage and can throw off thyroid balance. Patients who are on thyroid replacement have no need for iodine in excess of what is naturally occurring in their thyroid medication.”

According to Chris Kresser, “One word of caution is that it’s really important [when you] start iodine supplementation [to] start at a low dose and build up slowly over time. The reason is that if you go too quickly … [it] can provoke or exacerbate an autoimmune thyroid response, particularly if you don’t have enough selenium in your diet.”

Additionally, excess iodine intake can cause the thyroid to decrease productivity, temporarily, to protect against a hyperactive thyroid – it’s a self-preservation mechanism called the Wolff-Chaikoff effect.

But here’s a kicker. Iodine experts Dr. Guy Abraham and Dr. David Brownstein have had “great success” in treating those with Hashimoto’s with high doses of iodine. Really high doses.

Here is Dr. Abraham’s epic article on the topic, where he states that he administered his thyroid patients 50 milligrams (that’s milligrams, not micrograms – so we’re talkin’ 50,000 micrograms!) of iodine/iodide solution daily, with “fantastic” results.

These doctors have claimed that in Japan, where iodine intake is high, the population has low incidence of disease, including Hashimoto’s. But it’s also been found that Hashimoto’s cases are similar in Japan and the U.S.

They’ve also claimed that animal studies have proven that high dosing doesn’t fire up Hashimoto’s unless the supplementation is paired with “goitrogenic” foods. (Like we talked about last week, this whole “goitrogen” thing is a non sequitur.) 

But Dr. Christianson states, “I see all the unfortunate cases where high-dose iodine goes wrong.”

He calls iodine “the Goldilocks mineral,” stating, “Remember how Goldilocks wanted her porridge not too hot, but not too cold, and her bed not too hard, but not too soft? Iodine is like this. It is the Goldilocks mineral: too little is not good, and too much is not good. As vital as it is for your health, iodine can become toxic by as little as a few hundred extra micrograms. (Author’s emphasis.)

“The tricky thing about iodine is that if you have too little, there’s not enough to meet the nutritional requirements, but if you have too much, you blow the fuse and your thyroid quits working. Iodine in doses above nutritional requirements is the single best-documented environmental toxin capable of inducing autoimmune thyroid disease.”

Again, I think the dose makes the poison. Or in this case, the dose causes the Hashimoto’s/low thyroid function.

Although I’ve followed Dr. Brownstein for a while and love his sassy, bossy, no-nonsense approach to everything from statins to diabetes to thyroid health, I’ve never taken him up on his suggestion to flood my body with iodine. And I have a real problem with Abraham’s claim that it’s “obvious” that iodine deficiency, not excess, is the cause of Hashimoto’s.

It’s far from obvious! Iodine deficiency is not the cause of Hashimoto’s. I know puh-lenty of others who agree with me on this.

While it’s true that many with Hashimoto’s are deficient in iodine, Hashimoto’s is an autoimmune condition that, just like any manifestation of autoimmunity, begins primarily with genetic propensity (the least significant factor, contrary to what many will tell you), intestinal permeability, and environmental toxin exposure.

Then we have one of my favorite doctors, Dr. John Douillard, weighing in on the matter. Remember how we addressed the importance of iodine for breast health last week?

Dr. Douillard states, “Most experts agree that the current RDA for iodine, at 150 micrograms per day, may be too low. The new levels that I reported on in my article, “Protect Your Breasts,” indicated the need for 3-6 milligrams per day to inhibit toxic estrogens from absorbing into the breast. Thyroid expert Dr. Brownstein recommends a minimum of 1.5 milligrams of daily iodine and much more in cases of iodine deficiency or thyroid dysfunction.”

I haven’t read Dr. Brownstein’s claims and dosing recommendations in great detail, but I know that at one point, even he said that excessive iodine intake can aggravate Hashimoto’s.

Dr. Christianson says that the risks of high-dose iodine are “irrefutable” and he’s been vocal about how many have come to him for thyroid treatment after high doses of iodine. But he says, “To be clear, not all patients who take high-dose iodine will get thyroid disease, just like not all smokers get lung cancer.”

Are you confused enough yet? Me too.

Testing for Iodine
Many claim that an iodine patch test on the skin is helpful, but results differ so widely that the urine loading test is preferred and often considered the most accurate determination. A loading test measures the excretion of iodine over a 24-hour period.

You take 50 milligrams of iodine prior to the test. It’s thought that at least 90% of the iodine should be excreted in someone with sufficient iodine. If it’s less, they’re considered iodine deficient. In other words, the lower the excretion, the greater deficiency.

And according to Dr. Christianson, “Based on what we know about iodine, [the urine loading test] is not likely meaningful for the following reasons:

  1. We excrete iodine in our urine, but variable amounts leave though our bowels and sweat.
  2. Sudden, large doses can result in fecal loss 400-fold above normal.
  3. It has been stated that unless fecal and urine levels of iodine are measured, urine is not an accurate biomarker when iodine intake is changed abruptly, such as after a loading dose.”

ZRT has a version of the test – a urine spot test – that only requires two samples vs. the 24-hour collection. And they published a report on their website that calls into question the validity of it – stating most of the same concerns that Dr. Christianson states. Nonetheless, the test is still available and they’re a reputable lab.

One-time blood and urine testing has been said to be “useless.”

Even some doctors I respect still speak to the iodine patch test, knowing that it’s not perfect.

I can’t speak to the validity of any of these tests, but as far as I know, it’s what we’ve got.

What To Do?
I don’t know what to suggest you do. :)

Here are the considerations:

  1. Whether or not to supplement with iodine to begin with?
  2. If so, with what – are sea vegetables and seafood enough?
  3. Do you even have hypothyroidism/Hashimoto’s?
  4. If so, are you on thyroid hormone replacement, a source of iodine?
  5. Whether to use the sledgehammer approach, as suggested by Abraham and Brownstein, or the “tapping the nail into the wall” approach, as suggested by many others in the functional medicine community?

Regarding #3 above, Dr. Shames states, “What about the majority of the population that is not prone to autoimmune thyroid disease? Should they be trying to avoid iodine as well? The answer is no. The worldwide tragedy of iodine deficiency disease is still enough of a threat to warrant continued iodine supplementation for the ‘average’ person.”

Here’s what I’ve been recently doing and it hasn’t thrown me into stratospheric antibodies – or any additional antibodies. Or any symptoms.

I’ve been using:

  • Iodized salt again (I use sea salt too)
  • Lugol’s iodine drops

And once again, I’m asking my clients to maybe possibly consider iodine supplementation – with some explanations and caveats.

Some of the most popular iodine supplementation is Lugol’s and Iodoral.

Iodoral, the pill form of Lugol’s, comes in 12.5 and 50 milligram tablets – quite high doses.

Lugol’s comes in 2% and 5% and one drop of the 5% formulation is equal to 6.25 milligrams (6250 micrograms) of iodine. Assuming that the 2% is 40% of the 5% formulation, the 2% formulation would be 2500 micrograms.

But this is all confusing because you’re going to find different claims about the actual dosing. With regards to the 2% formulation, the company states, “You would get 3.125 milligrams of iodine out of a vertical drop and 6.25 milligrams out of a horizontal drop.”

Sigh. What the hell does that mean? Do I really need to split these hairs?

Or maybe they’re not hairs at all if it matters so much that they need to make this specification.

And given that the difference between the drop types means a doubling of halving of the dose, and given that both are already considerably higher than what’s being commonly recommended, I guess it matters.

It seems that iodine does have a very narrow therapeutic index.

I guess I’ll go with what the manufacture says, since they make the stuff, but I’ve also read from more than one source that one drop of the 2% is 2 milligrams or 2000 micrograms and also that it’s 2.5 milligrams or 2500 micrograms.

I don’t know…

Not having previously broken this all down, I started taking 2 drops of Lugol’s 2% iodine per day. A common recommendation is 2-5 drops, but with the addition of iodized salt in my cooking, I felt comfortable with 2 drops.

And as you can see from some of the recommendations from doctors I’ve quoted here, even one drop would be considered a high dose.

Dr. Christianson suggests 100-300 micrograms daily. And many doctors and professionals I respect recommend something in this range.

And again, I haven’t felt differently on this Lugol’s dose. I generally have very good energy, so it’s not like I was looking for a boost. I haven’t swung into a hyper state and my thyroid antibodies are still <30 (anything below 30 is considered “remission” or “managed” Hashimoto’s).

But there may be some benefit to “frontloading,” where you take a higher dose at the onset of supplementation and then ramp down.

Now I’m going to completely confuse the situation (surprise!) and also state that there’s some evidence that increasing your dose over time can be helpful. Chris Kresser states, “I’d recommend starting at a lower dose, like 250 micrograms, sticking with that for seven to ten days, maybe doubling it, sticking on that for seven to ten days, and then proceeding to increase from there.” But I haven’t found where he states what he feels the maximum dose should be.

Pure Encapsulations makes a good iodine/tyrosine supplement. Because it’s relatively easy to get plenty of the amino acid tyrosine (especially if you’re not a vegetarian), I don’t often recommend supplementing with it. But I like this particular product – it’s only 225 micrograms of iodine per capsule.

Writing this schizophrenic post has convinced me that this Pure Encapsulations product is likely the right supplement for me. Or maybe none at all, given my salt and sea vegetable intake.

I’m just as confused as you are.

And remember, if you’re on thyroid hormone replacement, you need to take this into consideration. Dr. Christianson states, “If you have thyroid disease or others in your family do, you may be more at risk of the danger of too much. If you are on thyroid medications, you already receive substantial amounts of iodine.”

A quick word about kelp. Many iodine and “thyroid support” supplements use kelp (aka kombu). And many people are drawn to kelp because they consider it a “natural” form of iodine. (Many iodine supplements are potassium iodide.)

But it’s just as risky to get too much iodine in the form of kelp supplementation as it is any other form of iodine.

A Summary???               
I hope I’ve provided you – something in this two-part tome. As I explained in Part 1, after reading all of this, you may not be any wiser as to whether you should supplement with iodine. Again, my intent was to simply do my best to provide both sides of this very two-sided story.

To wrap this up, here are my general suggestions, whether you choose to supplement or not:

  • Consider minimal use of iodized salt; perhaps use sea salt and iodized salt interchangeably.
  • Eat sea vegetables 1-2 times a week (dulse, wakame, nori, etc.).
  • Eat fish and seafood twice weekly: scallops, cod, and shrimp are said to be the best sources, but salmon, sardines, and tuna are also good choices. And make sure it’s sustainably-sourced vs. farmed.
  • Based on the dangers of bromine, chlorine, and fluoride that I presented last week (remember, they can displace iodine): filter your water to reduce chlorine and fluoride exposure, avoid flame retardants as much as possible (they’re a significant source of bromine and mattresses are the most offensive use of flame retardants), and swim in salt water to avoid absorbing chlorine through your skin.
  • Avoid added fluoride in toothpaste, dental treatments, and some teas and medications. (More on fluoride in five weeks.)
  • Eat organic as often as possible. Insecticides contain chlorine and bromine.
  • Eat other foods rich in iodine: potatoes with skin on, egg yolks, turkey, and, believe it or not, strawberries. *
  • Watch out for iodine levels in your multi-vitamin, including prenatals.
  • Minimize the consumption of canned, packaged, and fast food, as most of the salt in these foods is iodine-fortified. It all adds up.
  • In the same vein as the last point, cook more at home. Even if you’re eating out at the best restaurants, they’re often using iodized salt. At home, you can control the type of salt and how much you use.

There’s no question – we need iodine. So at the least, I hope that you’re able to get more sea vegetables (nutritional powerhouses!) and safe seafood into your diet.

I’ll leave you with this. As one doctor in my nutrition education program stated, “Nutrition is the only science in the world where diametrically opposed theories can be proven right because we’re all bio-individually unique.”

* Important note for this whole Minerals series: You may see some slight discrepancies in the list of foods in this post and the list of foods in my thyroid- and immune-supportive nutrition chart (which you can download for free here). This is because for the chart, we created a ranking system. If each thyroid- and immune-supportive food didn’t have a broad enough nutritional spectrum such that it represented enough nutrients, it didn’t make the cut. In other words, the list in this post may be slightly more inclusive.


Hello, I have Hashi and unfortunetely I did take some iodine for 6 months to get my iodinelevels up. I  was able to increase the level of iodine, but antibodies went skyhigh. What is the safe amount iodine from food daily
taking into account what happened? I'm 53 years old and my cortisol levels are low also.

Thanks Pia

Blair Shackle's picture

Hi Pia,

Thank you for your comment. Your question represents a complex condition and cannot be answered responsibly on a blog comment. We’d love to help you – if you’d like to speak with one of our coaches, you’re welcome to schedule an introductory session via our Contact page.

great article but it wasn't clear if iodine supplementation is a possibility with Grave's disease. Grave's was mentioned briefly in the Part 1 blog post but not this one. What are the pros and cons of iodine supplementation with Grave's? Thank you for any input.

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