This is a post for you who maybe know, or suspect, you suffer from iodine deficiency. But at the same time, you may be scared of supplementing with iodine. In this post, I won’t be referring to heaps of studies, as I want to keep it easy and assessible. But everything I write, I have read in books or studies. Except when I write “I believe” or “I think”.
Iodine deficiency
A lot of people suffer from iodine deficiency. And even more so us with thyroid disorders. Iodine deficiency is the number one reason for thyroid disease. I am not saying it’s the only reason. There is an almost phobia of iodine in the world, you can read more about that here
At the same time as we often get too little iodine, we have big issues with other halogens occupying the iodine receptors. Iodine is a halogen, and toxins like fluoride, bromide and chloride can occupy the iodine receptors. This happens less if we have ample iodine in our bodies.
We get a lot of fluoride in our tooth paste. Bromide from our furniture as flame retardant. In the US, they apparently even add bromide to bread! Which is very difficult to understand. In some countries, chloride is added to drinking water, and of course, it’s in our pools.
Deficiency symptoms
- Tiredness
- Freezing
- Weight gain
- Dry, scaly skin
- Hair loss
- Low stomach acid
- Dry eyes
- No sweating
- Goiter
- Thyroid nodules
- Fibromes and cysts in breasts and uterus/ovaries
- Brain fog
- Low IQ and in worst case scenario, cretinisme in the fetus
Of course, many of these symptoms are symptoms of low thyroid levels, and will disappear as we become euthyroid, have good thyroid levels. You can read more about that here, For the thyroid newbie and here, Optimal thyroid levels. BUT far from all. Many with thyroid disease still have many of these symptoms DESPITE good thyroid levels. Many believe, even doctors, that the thyroid is the only organ in the body in need of iodine. This is not the case. ALL glands in the body need iodine to function. Breast glands, ovaries, the prostate, the little glands excreting stomach acid, tear film and so on.
So even if you now get thyroid hormones, if you are taking that, all these other glands in the body are not getting the iodine they need.
NB! If you have a hot nodule in your gland, do NOT take iodine. The nodule might absorb the iodine and make even more thyroid hormone. And you will become more hyper. If you are hyperthyroid and you are not sure, whether you have a hot nodule or not, you need to be careful as well. A hot nodule needs to be surgically removed.
Isn't iodine dangerous for people with Hashimotos?
This is the most common comment, that iodine is dangerous for those suffering from Hashimotos. One of Norway’s better known endocrinologists, Ingrid Norheim, told me in 2007 that I should avoid ALL iodine , even the 150 mcg in multivitamins. I listened to her, unfortunately. I understand now, I was severely iodine deficient at that time, and had been for years. I believe she has become wiser. I hope so at least.
There are two kinds of Hashimotos, the one that starts with goiter and the one without goiter. The latter is in reality Ord’s disease or Ord’s anthropic. It was a doctor named Ord that diagnosed it, years before Hashimotos named the AIDT with goiter. Why do I mention this?
It’s because, with Ord’s, the gland atrophies. After some years, one has little or no gland. I belong to this group myself. While those with “real” Hashimotos can have a full size gland after years of disease. And it’s not the case either, as many say, that anti-TPO “eats” our gland. One can have high levels of anti-TPO for years without the gland decreasing in size. But it doesn’t function, it’s infiltrated by t- and b lymphocytes. And the TPO enzyme is damaged, you can read more about that here.
Why does this matter in terms of iodine supplementation? It’s because all thyroid anti bodies are produced inside the thyroid itself.
So if you have little or no thyroid tissue, you don’t have to worry about increase in antibodies when taking iodine. There will be no antibody flares. You might have a little antibodies even if you have an atrophied gland. I have a little anti-TPO still. But then I have some thyroid tissue left.
What about people WITH a gland?
When you have a gland, it’s wise to be a bit more careful. It’s not so much increase in anti-TPO one needs to worry about, but more anti-TG and TRAb. Especially the first. According to a scientist called Michael Zimmermann, we don’t know if the increase in anti-TG is transitory or more chronic. I recommend him as a serious investigator of iodine. He realizes the importance of iodine.
What Zimmermann also writes, and which is important, is that one sees a sharp increase in anti-TG especially when someone has been iodine deficient for a long time, and then suddenly gets a lot of iodine. One sees this when a country starts iodizing the salt. In the countries where they have started on a high addition from the get go, one has seen a big increase in anti-TG. Whereas in the countries where one has added iodine a little at the time, there has been less increase in anti-TG.
One used to say, high levels of anti-TG didn’t matter that much. But now there are some studies saying, that anti-TG is more dangerous than one used to believe. It has a greater ability to kill thyrocytes than anti-TPO. I write about this here.
This is why I advice starting low and increasing over time if you have a thyroid. And especially if you have functioning thyroid. If you have had Hashimotos for years, your thyroid does not function anymore. Which is why you need thyroid hormones. The gland will be infiltrated, and it will never be healthy again, I don’t think. In that case, there is no danger of further damage to the gland by ingesting Iodine. The gland is already destroyed, more or less. After many years of thyroid disease, I think everybody deserves an ultra sound of their gland. It’s the only way of truly seeing the state of the gland.
If this is the case with you, you have to decide if an increase in antibodies would worry you or not. High levels of antibodies are connected to symptom load. High dose iodine can clear up thyroid antibodies as well. But you never know which way it will go.
If you are just in the beginning of thyroid disease, you have anti-TPO and/or anti-TG over range. Or your FT4 is becoming too low, under 40% of range, then I think “low and slow” is the safe way to go. If your thyroid is healthy, and you don’t have thyroid antibodies over range, then it’s much safer to start high dose iodine. As long as you take selenium. IT’S WHEN YOU ARE IN THE BEGINNING PHASES OF THYROID DISEASE THAT YOU REALLY NEED TO BE CAREFUL.
The problem is, that’s it at this stage many start high dose iodine. In the hopes of fixing their beginning thyroid issues. And we often know very little about thyroid disease at this stage. Things can go wrong, and I see it happening in iodine groups. People damage themselves with iodine. I hope my warning voice reaches someone. And remember, I love iodine and take it every day. I am not an iodine phobic. But better safe than sorry!
Dosing
Those with a functioning gland should start with 2 to 300 mcg. I see, Kris Kresser starts his patients up on 325 mcg. Test antibodies BEFORE you start. then follow up with frequent thyroid testing including for antibodies in the first months. Then you can’t go wrong. Increase dose when you feel safe about it. See under for safe max doses.
Lots of people with a functioning thyroid gland can do high dose iodine. But if you want to make sure, you don’t damage your gland, then starting low is the wise choice.
Those without a functioning gland can start on higher doses. You can do the Iodine protocol if you feel like it. If you feel safer supplementing lower doses, start with 3 to 500 mcg, and increase over time. I think one can safely take up to at least 2 mg without issues, see below. When one does the Iodine protocol, one can get detox symptoms. It can also be hard on the kidneys with all that iodine And one needs to really study before starting on large doses. You can read more about the Protocol here.
What iodine to take?
Take a supplement where you can see the exact content. If you take a sea weed supplement, take one where the amount of iodine is listed. I see in American iodine groups, that many consider sea weed to be full of toxins. I believe this fear is exaggerated. We get so many toxins, I don’t think small amounts of sea weed is the biggest culprit. Some swear by nascent iodine. Others by Lugol’s. Taking a supplement with little iodide is safer for the thyroid, iodine is less absorbed by the thyroid. I write about that on my nerd’s post here.
Lugol’s contain both iodide and iodine, 2/3 iodide and 1/3 iodine. It’s high dose iodine, but one can dilute it to smaller doses. I guess it’s difficult to get an accurate, small dose. Seaweed contains both iodide and iodine. i don’t think one should take iodide only, potassium iodide, I-. Iodine is also more antioxidant.
Selenium
Selenium is the most important thing when taking iodine. Do not take iodine with poor selenium levels. Selenium protects the thyroid. All enzymes involved in the production of thyroid hormones and hormone conversion, are selenium enzymes. I read an article in The journal of the Norwegian physicians, written by 3 doctors, the current reference range for selenium is way too low. They argued, that we need to have as high as 3 umol/L in serum. Reference often goes to 1.8 or 1.9 umol/L today. And that it is levels over 3.5 umol/L that can be toxic. You can convert these numbers to your units in an online units converter, https://unitslab.com/node/210. These doctors wrote, one needs to take 300 mcg/day to achieve such levels.
Many have been worried about overdosing on selenium, but maybe we can stop worrying about that at least. I have increased my selenium intake after reading this.
Other supplements
On the iodine protocol, people take several other supplements. Large doses of niacin (B3) and riboflavin (B2). B3 can give temporary flushing. One needs to buy the no-flush kind. Even then one can get a flush if the dose is high. These two vitamins are important for the ATP function in the mitochondria. I think it’s good for all hypo thyroid to have good levels of these two, as we have a metabolism dysfunction. But I don’t really know how important it is when doing small dose iodine.
People also take magnesium and sea salt. Sea salt is important for detoxing bromide. When we take iodine, we can start detoxing the other, toxic halogens, fluoride and bromide. Which is a very good thing, but one can get detox symptoms. I don’t know to what extent this happens on low dose iodine. But just keep it in mind.
Testing your thyroid
Please take care to test your anti-bodies if you still have a thyroid. Anti-TPO, anti-TG and TRAb. You also need to keep an eye on your thyroid levels. they can both increase and decrease. Your thyroid can start producing again, and you can become hyper. In that case you will need to decrease your thyroid meds. And that is just great 
I have read some people saying, if you go hyper, that is a sign you take too much iodine. NO, it’s not. It’s a sign you take too much medicine. If you are not taking thyroid meds, then of course, you should not go hyper and need to have your TRAb tested asap. You could have gotten Graves. And again, if you have a hot nodule, do not supplement iodine.
Elevated TSH
If your TSH should go up, but FT4 and FT3 stay normal, that is nothing to worry about. The TSH is not actually just a signal hormone. It is also involved in making new symporters, the channels whereby iodine is channeled into the cells. The TSH can rise for a few months in this process.
Your levels can also go down. My FT3 went down, I am sorry to say. I have to increase my dose. I have seen this also with other people in iodine groups. I was very puzzled by this, shocked even. But I read on Kris Kresser’s blog, that large doses of iodine can inhibit all selenium enzymes, like TPO and all the conversion enzymes (deiodinases). That is, the enzymes converting T4 to T3. I guess that makes sense in my case. I don’t have much TPO enzyme, but I do hopefully have D1, D2 and D3 deiodinase. And these can have become inhibited. But at the same time, I take NDT and get a lot of T3 in my meds. And I certainly don’t convert well. But maybe there is conversion going on.
Maybe this become a bit complicated for you. The point is, keep an eye on your levels.
Temperature and pulse
The best thing is always to follow pulse and temperature. There is a difference between morning- and evening temperature. Some say, our temperature is individual. I don’t believe that. I think our evening temperature needs to be 37 to 37,2 ° C/ 98,6-98,9 ° F. Taken inside the body, vaginal or rectal. Concerning pulse, so many hypothyroid live with too low pulse. I did myself for years. I personally am good when morning pulse is around 68, and daytime pulse around 78/80. Morning pulse at 60 or under is in my view hypo thyroid. Unless you are an athlete 😉
Iodine testing
Iodine needs to be tested in urine. In serum is no good. There are various ways to do it. The best test, is the 24 hours iodine loading test. In the US you can get it from a couple of labs, Hakala is one of them. It’s quite expensive. We can get the Hakala test here in Europe as well, from Biochorence.eu. It costs a lot. Many labs offer 24 hours test where you just collect the urine for 24 hours, and include the morning urine. then send off a sample. And there is urine spot tests, which is the morning urine. I think the 24 hours is better. Some say no iodine testing is accurate. I am the kind who like to test things. I have only taken the Hakala test so far. But if I took a 24 hours test, I would want to lie high in range. Excessive even.
Here is a table of 24 hours testing from Zimmermann, link
Tilt phone to see the full table.
| Iodine intake | Iodine nutrition | |
|---|---|---|
| School-aged children and adults | ||
| <20 μg/L | Insufficient | Severe iodine deficiency |
| 20–49 μg/L | Insufficient | Moderate iodine deficiency |
| 50–99 μg/L | Insufficient | Mild iodine deficiency |
| 100–299 μg/L | Adequate | Optimal |
| ≥300 μg/L | Excessive | Risk of iodine-induced hyperthyroidism and autoimmune thyroid disease |
| Pregnant women | ||
| <150 μg/L | Insufficient | .. |
| 150–249 μg/L | Adequate | .. |
| 250–499 μg/L | More than adequate | .. |
| ≥500 μg/L | Excessive | .. |
| Lactating women | ||
| <100 μg/L | Insufficient | .. |
| ≥100 μg/L | Adequate | |
I believe that those without a thyroid can safely take at least 800 mcg. As you see from the table under, the highest recommended intake in the US is 1100 mcg. The European scientific committee says 600 mcg, whereas WHO says 40 mcg pr kg body weight for pregnant and lactating women. That means a pregnant woman weighing 70 kg can take 2800 mcg. They don’t say anything about other adults. But they give very high levels for babies and infants. In Japan the upper limit is set at 3000 mcg.
Tilt the phone to see the full table.
| Age group | IOM (μg/day) | SCF (μg/day) | WHO (μg/kg/day) |
|---|---|---|---|
| Premature infants | ND | ND | 100 |
| 0−6 months | ND | ND | 150 |
| 7−12 months | ND | ND | 140 |
| 1−3 years | 200 | 200 | 50 |
| 4−6 years | 300 (4−8 years) | 250 | |
| 7−10 years | 600 (9−13 years) | 300 | 50 (7−12 years) |
| 11−14 years | 450 | 30 (>13 years) | |
| 15−17 years | 900 (14−18 years) | 500 | |
| Adult | 1100 | 600 | |
| Pregnant and lactating women | 1100 | 600 | 40 |
This table is from this study. It also says further down
The lowest observed adverse effect level (LOAEL) proposed for iodine intakes based on these studies is 1700−1800 μg/day, based on a mild increase in thyroid‐stimulating hormone (TSH) that was not associated with clinical adverse effects
And as you remember, one can have an increase in the TSH for the first few months of iodine supplementation. And that this is a positive thing.
Conclusion
Don’t be afraid of iodine. I have been taking large doses of 25 to 50 mg, as I wanted to detox fluoride and bromide. As well as achieving a good iodine status. I have been iodine deficient for a very long time. And it has certainly contributed to my Hashimotos. It’s a long time since I stopped sweating.
But as I have said maybe too many times, high doses are not for everyone. Small doses ARE for everyone, except those with hot nodules. It’s safer to take it low and slow. But don’t be so afraid of iodine that you don’t try supplementing. If you read this, you have a feeling that you need it.
I feel much better after taking iodine for about 11/2 years. More awake, improved memory, warmer, my back is straighter, my skin is less dry, my eyes are less dry, sweating better. Right now, in February 2022, I take 5 mg nascent iodine/day.
I see many in a Norwegian thyroid group I am in, who also feel better for taking iodine.
We must have iodine!
Good luck!
Dear Liv, thank you for your very informative blog. I live in a 3rd World country and do not have medical insurance – it is too expensive, and I very rarely ever need to go to the doctor fortunately. I am 62 and mostly in good health. I follow alternative health blogs and have learnt so much from people like you. My mother was on thyroid medication for an underactive thyroid for many years before she passed away at the age of 83. She took half a tablet every single day. A doctor prescribed the same medication for me over 10 years ago, but I was reluctant to go on it as I prefer to try and find a natural solution to health problems. I do not take any other medication on a regular basis, just the very occasional headache tablet. A year ago I started taking a drop of 2% Lugols in a glass of water every day, and have worked very slowly up to 8 drops a day, with no issues whatsoever. I haven’t tested my selenium levels, but from the research I feel there is adequate amounts in my diet. I believe I have completely eliminated flouride, bromide and chloride from my system, I eat a very clean diet with meat, eggs and dairy, and mostly organic meals prepared from scratch.
My reason for writing to you is that I have struggled with hot flushes for the past 20 years. I have always “run hot” with a ruddy complexion, and sweat a lot. I have never had a weight problem (I am only 2 – 4 kgs off my ideal weight) and am fairly active – I do all my own housework, garden, and walk for about an hour a day over and above that, and I do yoga. I had a partial hysterectomy at age 47 because of fibroids and very heavy periods. I resisted the operation for a long time, hoping to stop the bleeding naturally, but with no luck unfortunately, and I became dangerously anaemic. I had hoped that the flushes would disappear because of my age and having come through menopause. But the hot flushes continue unabated, especially at night, I have dry eyes often, and I get a very itchy patch on my lower left arm when I am anxious. Do you think it would be helpful to increase my daily Lugols intake, and to how many drops? Also, can you suggest any thing else that I could be doing to stop the hot flushes.
Thank you for your interest in helping others understand their thyroid issues.
Hi Joy!
So glad if my blog can be of help to people who don’t have access to proper health care. I do see that I have visitors from all over the world, and I am of course thrilled and awed by that.
It seems like you are a very concious peron with a lot of knowledge of health issues. I don’t agree with you on everything though. I absolutely think that you should take thyroid hormones if your levels are low, and that not doing so is very detrimental to one’s health. But it sounds like you are feeling fine. But if you start feeling tired and cold, I hope you have your thyroid tested and take meds if too low. You will find a lot of info on what is really normal on my Optimal thyroid levels.
Your uterine fibroids were probably due to iodine deficiency. I have had the same thing, a hysterectomy because of fibroids. Heavy periodes can be caused by low thyroid levels. Just so you know. I cannot advice on how much iodine to take, this is something everyone must decide for themselves. You are already on a large dose, 17,5 mg. What would worry me, is if you can’t have your thyroid antibodies and thyroid levels tested. You don’t need tests for the levels. You can take your temperature in the middle of the day, rectally or vaginally. Over a few days, it should be 98,6 F/37 C. Pulse should not be low. Over or under you will most likely be hyper or hypo. But antibodies are another matter. There could be a lot going on that you don’t know about. And even more likely if your mother had thyroid disease. So if it was me, I would err on the side of caution. Not taking selenium I think is very unwise. Really. Selenium protects the gland, and every iodine doctor stress the importance of selenium. You have to take a lot for it to get toxic. I have some newer info on selenium levels here odds-and-ends. Please think about that.
Your hot flashes. I am sure you think it has to do with sex hormones. You have probably tried many things already, so not sure if I can help. For me natural progesterone is so important. But you might not want to take any hormones. Some people are more sensitive to low sex hormone levels than others. I am that way, I got so nervous at meno pause, I didn’t recognize myself. I have used both estradiol and natural progesterone. Both it’s not adviced to start on estrogen treatment after 60. I do think estriol is much safer though. I look at sex hormones Female hormones
You can get progesterone and estriol on Iherb. But I don’t know if that is an option for you. Natural P is made from mexican wild jam. One can also get it in capsules. Dong Quai (Angelica sinesnsis) a herb much used in the East for anything female. I have used it a lot. Then you have Black Cohosh (Actaea racemosa) helping with hot flashes. Sage is also a good herb. Hot flashes and high cortisol can also be connected. Do not use ginger, it gives heat in the body.
I hope you can use some of this.
Blessings, Liv
Hello and thanks for the useful information.
I need some advice. I have been taking a high dose of Lugol between 40-50mg for almost six months. In order to melt a huge breast cyst. I was climbing slowly all the time. And finally, it disappeared, wow! I have had it for over 7 years no other natural methods have been able to clear it. I should note that I am hypothyroid but I have not been on medication (now I consider it a mistake) my TSH has always been around 5, after I started Lugol it went up to 21, then dropped to 7. Once I got through the Bromide clean-out crises, I felt really good-brain fog gone, body aches too, as well as period migraines gone, and I had energy and clear thinking…I continued a little more on 50 mg. to make sure it was gone before I reduced the dose. And then suddenly I went into hyperthyroidism- I lost 3 kilos in a week without changing anything, I even ate more, but the worst I got was heart palpitations, over 100 pulse at rest, I broke out the sleep (I used to sleep deep sleep, now I couldn’t sleep) and this lasted for four days until I stopped the Lugol. I suspect selenium may have done this, (Before it was high, and for that, I was taking moderate amounts), I was doing two days of salt pulsing regularly. I’m going to run thyroid and selenium tests. But I don’t really want to stop with Lugols, because I saw that they help me, I wonder if it’s good to continue with low doses up to 12mg.?
Hi Nadia!
The short answer is, no it’s not good to continue the Lugol’s. You need a full thyroid panel, including all 3 antibodies. Anti-TPO. anti-TG and TRAb. If this is a case of Graves or you can have a hot nodule, I don’t know. Do not take any iodine until test results come in. Be careful, thyrotoxisis can be very dangerous. I don’t think this has anything to do with selenium levels. I hope you will take better care of your thyroid health in the future. Read my post on Optimal levels.
Best of luck, Liv
Thanks for the reply Liv,
the tests came out, my TSH is 0.1, T4- 90, and Antibodies are normal – that’s what they told me. I stopped Lugols and in a month we will run tests again. I’m worried about my breasts as they obviously need iodine, before I started Lugol they were firm and cystic with this big cyst over 3cm, the iodine cleared it all up but I must have gone wrong somewhere….
All the best,
Nadia
Hi!
Make sure to get all the tests I adviced, escp. FT4 and FT3. I suspect that you have a hot nodule. It’s a nodule that produce thyroid hormone on it’s own. One must never take iodine if one has a hot nodule. That has to be removed first. The iodine can stimulate the nodule to produce more hormones. If your thyroid levels continue to be high, you need an ultrasound of the gland. I don’t understand the T4 90. One has to be accurate, and include the units and reference ranges. I won’t be replying more now. I have all the info on what’s normal levels on my Optimal thyroid levels.
You need to figure out what’s wrong with your thyroid first. Then you can think about what to do about supplementing with iodine. In my opinion.
All the best, Liv
I took Lugols for 8 months in 2016 on a protocol to treat thyroid nodules (5). And it worked! Not one nodule was detectable on an ultrasound a year later. However, I lost a TON of hair in that year. I later learned that’s because I’d been dying my hair at home every couple months for years…. the bromine level I had in my hair follicles was probably off the charts. I believe the iodine fought for that space and my hair lost the fight. oh well. 6 years later I still didn’t completely recover my hair volume, but also I have no nodules and a normal size thyroid. although I do still have hashimotos that I keep in check with diet, I think I should be upping my iodine again for maintenance. thank you for the article!
Hi Stephanie!
I know some people loose a lot of hair on iodine. I am not sure about the cause though. One’s ferritin can become low on iodine. That could be one reason. Many are hypothyroid. That is another reason for hair loss. I see too many these days, who think they can drop, or stop, taking thyroid meds. I am sure some can drop meds, but many are actually hypo and in need of meds. Holding off taking thyroid meds is not a smart thing to do. Some people believe, if you take meds, your own thyroid stops producing. This is not the case. The gland produces as long as it is able to produce. And if you take meds, and your gland becomes more healthy and starts producing more than it has; your thyroid levels will rise and you can reduce the meds.
What happens if one lives with too low levels, is only that one becomes sicker. So I hope you will have a look at my optimal thyroid levels page, here. And make sure your levels are really ok.
I hope you have read this post, and that you take it slow with the iodine. And have anti-TG tested before and during. We all need iodine, but for those with an AITD and whose gland still produces, they are the ones who need to be careful. Also, if you do start taking meds at some point, many get great hair on NDT. Myself included .
All the best, Liv
How much Lugols are you taking? I just ordered the 1% version but it just says `talk to your practitioner` under `dosage`. One drop = 1,25 mg of iodine. Some say take one drop a day, some say one drop every two weeks, some say 6-9 drops a day…confusing! I have an atrophied gland due to autoimmune disease.
Hi Anna!
I don’t think anybody will tell you how much you should take. Except for an iodine literate doctor. I have written this post in order for people to be able to decide for themselves. I have read a lot of papers and am sharing what I have learned. As I write in the post, if you have very little thyroid tissue left, taking iodine is not very risky. Very large doses may put a strain on the kidneys, so keep an eye on the kidney numbers or reduce dose if you feel any pain in the kidney region. I am talking about several mg’s here. You can read about my experiences on this post, under “My experiences”, THE IODINE PROTOCOL
Best of luck, Liv
High dose iodine 25mg lugols gave me dozens of cysts, I really believed it could help me.
Hi Mags!.
That sounds very concerning. I haven’t heard about that before. I HAVE heard about cysts getting smaller. I have got a cyst in my breast myself, but unfortunately I did not have an ultrasound before I started on high dose iodine. I think it is safer for a lot of people to do lower doses. That is why I wrote this post. The premise for high doses is that the Japanese get 12.5 mg a day in their food. This is what Dr.Abraham, Brownstein and Flechas claim. But the Japanese do not ingest 12.5 mg. They ingest more like 1 to 3 mg. You can read about that under Japan here . They refer to some old studies, but there are newer and better studies on this. Where many parameters are taken into consideration. I find it strange that they don’t seem to keep up with the science. Nowhere does one get such high amounts of iodine. One would need to eat a lot of combu every day. And not cook it, as most of the iodine evaporates when heated.
I hope at least I can contribute to people thinking things over.
Blessings, Liv