Iodine and Hashimoto’s Thyroiditis, Part 2

Mario Renato Iwakura’s guest series on the place of iodine and selenium supplementation in treatment of hypothyroidism continues. This is part 2. Thank you Mario! – Paul

UPDATE November 2023: Since this article was written, PHD recommendations for iodine have become firm. We recommend consistent daily supplementation in the range of 150 to 225 micrograms (not milligrams) per day, plus frequent seafood consumption. The supplementation (a) ensures a healthful supply of iodine and (b) accustoms the thyroid to the presence of iodine which minimizes the risk of thyroid injury from intake of a large amount of iodine at once, possibly at a time of selenium deficiency, for example from an all-you-can-eat crab buffet. Supplementation of >1 mg high doses of iodine carries a high risk of thyroid injury, making some parts of the thyroid hypothyroid and possibly also creating nodules with hyperthyroid activity. … Although our recommendations are not in line with Mario’s, nevertheless Mario’s article is fascinating, and a few people have reported benefit from high-dose iodine. Please read his article and judge for yourself! Best, Paul

In Part I (Iodine and Hashimoto’s Thyroiditis, Part I, May 24, 2011) we looked at evidence from animal studies that iodine is dangerous to the thyroid only when selenium is deficient or in excess, and that optimizing selenium status allows the thyroid to tolerate a wide range of iodine intakes. In fact, there were some hints (such as an improved CD4+/CD8+ T cell ratio) that high iodine, if coupled with optimal selenium, might actually diminish autoimmunity.

If that holds in humans too, we should expect that populations with healthy selenium intakes should see a low incidence of thyroid disease and no effect from iodine intake on the incidence of Hashimoto’s thyroiditis. Is that the case?

Korean Study

Dr. K [1] quotes a Korean study [3] of Hashimoto’s patients. Half restricted iodine intake to less than 100 mcg/day, the other half ate their normal seaweed and iodine. Of the 23 patients who restricted iodine, 18 (78%) became euthyroid in the sense of having TSH below 4.43 mIU/L, while only 10 (46%) of the 22 that did not restrict iodine became euthyroid. There was no measurement of symptoms at all, and no report of thyroid antibody titers after iodine restriction, so we don’t know if the iodine restriction relieved the underlying autoimmune disorder.

The selection of subjects for the two groups was odd. Group 1, the iodine restricted patients, had an extremely wide range of starting TSH, averaging 38 mIU/L but with a standard deviation of 82 mIU/L. Since all subjects began with TSH above 5 mIU/L, it’s clear that many of the Group 1 members had TSH near 5 and others had TSH well over 100 mIU/L. In comparison, Group 2, the controls, averaged a TSH of 11 mIU/L with a standard deviation of 11 mIU/L – less than 1/7 the standard deviation of Group 1. Few Group 2 members had a TSH above 30.

Table 2 presents the results. Mean TSH in Group 1 was reduced a little, but it did not even come close to normal. Since 78.3% of Group 1 had TSH below 4.43 mIU/L after 3 months, the other 21.7% had to have averaged a TSH above 102.2 mIU/L at the conclusion of the study. The standard deviation of Group 1 TSH at the end of 3 months of iodine restriciton was 71 mIU/L.

Meanwhile, Group 2 members still had a much lower standard deviation at the end of the study: 19 mIU/L.

A conclusion of this study was that “the initial serum TSH concentration was significantly lower in the recovered patients than in the non-recovered patients, which suggests that the possibility of recovvery is increasingly rare as the initial hypothyroidism becomes more severe.” Since Group 1 originally had a much larger fraction of members with very low TSH than Group 2 (plus a few with extremely high TSH to raise the average TSH), and the definition of recovery was a reduction of TSH to 4.43, perhaps it is not surprising that a higher fraction of Group 1 recovered.

Further calling into question the conclusion that lower iodine intake is beneficial is another observation. Looking at Table 1, we see that Group 2 (controls) had, at baseline, much higher iodine intake and higher urinary iodine excretion. Despite this, goiter size, TSH, antimicrosomal (MSAb) and antithyroglobulin (TGAb) antibodies were all lower!

A Japanese Study

A similar study with similar results was done in Japan [4].

In Asia, high iodine intake is due to high consumption of seaweed. Seaweed is high in naturally produced bromine compounds [5][6][7], arsenic [9][12][13], and mercury [9], and can accumulate radioactive iodine [8][9][10][11]. All these substances are known to interfere with thyroid function.

Bromide levels in urine in Asia are very high and are associated with seaweed consumption [6][7]. Values of 5 to 8.1 mg/l have been observed among Japanese, and 8 to 12 mg/l among Koreans.

It is quite possible that any benefits from “iodine restriction,” i.e. seaweed restriction, were due to reduced intake of bromine, arsenic, mercury, and radioactive iodine.

A China Study

Dr. Kharrazian [2] cites a study done in China [14] comparing three different areas: one with iodine deficiency (Panshan), another where iodine is more than adequate (Zhangwu) and a third where iodine is excessive (Huanghua). More than adequate and excessive iodine was associated with increased risk for subclinical and overt hypothyroidism.

But, another study [15], done in the same regions, showed that, coincidentally, Huanghua, the region with excessive iodine, and Zhangwu, the region with more than adequate iodine, had lower median serum selenium concentrations than Panshan, where iodine was deficient. Blood selenium concentrations were 83.2, 89.1 and 91.4 microg/L, respectively. So iodine consumption was inversely related to selenium consumption. Was it lower iodine, or higher selenium, that was beneficial?

TPOAb antibody levels were inversely associated with selenium levels. Patients with the highest TPOAb antibodies (>600 UI/ml) had lower selenium levels than patients with moderate and lower TPOAb antibodies (respectively 83.6, 95.6 and 92.9 UI/ml). [15]

Studies from Brazil, Sri Lanka, Turkey, and Greece

Dr K also cites a rise in Hashimoto’s incidence in Brazil, Sri Lanka, Turkey and Greece after salt iodinization began. Are these countries deficient in selenium? Well, lets see:

Brazil: The study was done in São Paulo, a city with a large Brazilian-Japanese population. Brazilian-Japanese have significant lower levels of Se than Japanese living in Japan [16].

Greece: Selenium status is one of the lowest of the Europe [17].

Turkey: Selenium status of Turkish children is found to be unusually low, only 65 ng/ml in boys and 71 ng/ml in girls [18]. Turkey is characterized by widespread iodine deficiency and marginal selenium deficiency [19].

Sri Lanka: Significant parts of the Sri Lankan female population may be selenium deficient [20].

One study, done in Egypt, measured iodine excretation in urine and its relation with thyroid peroxidase antibody (TPOAb) [21]. Although the abstract said that a significant correlation was found, this is far from reality, as we can see from Fig. 2.

Another study from Brazil [2] measured urinary iodine excretation and serum TPOAb and TgAb antibodies from 39 subjects with Hashimoto’s, none of whom were receiving treatment at the time of the study. Both antibody titers had no obvious correlation with urinary iodine.

Two discordant epidemiological studies

From the Netherlands, we have a prospective observational study looking at whether the female relatives of 790 autoimmune thyroid disease patients would progress to overt hypothyroidism or hyperthyroidism [22].

Although the relationship was not considered statistically significant, they found that women with high iodine intake (assessed through questionnaires) were 20% less likely to develop thyroid disorders.

Another study from western Australia (a region that has previously been shown to be iodine replete) measured urinary iodine concentration (UIC) of 98 women at 6 months postpartum and checked their thyroid status both postpartum and 12 years later [23]. UIC at 6 months postpartum predicted both postpartum thyroid dysfunction and hypothyroidism  12 years later:

The researchers concluded:

The odds ratio (OR) of hypothyroid PPTD with each unit of decreasing log iodine was 2.54, (95%CI: 1.47, 4.35), and with UIC < 50 lg/l, OR 4.22, (95%CI: 1.54, 11.55). In the long term, decreased log UIC significantly predicted hypothyroidism at 12-year follow-up (p = 0.002) … The association was independent of antibody status.

In short, the more iodine being excreted (and thus, presumably, the more in the diet and in the body), the less likely were hypothyroid disorders – not only at the time, but also 12 years later.

Dangers of selenium supplementation in iodine deficiency.

Selenium supplementation when iodine and selenium deficiencies are both present  can be dangerous, as the experience in northern Zaire, one of the most severely iodine and selenium deficient population in the world, shows [25].

Schoolchildren and cretins were supplemented for 2 months with a physiological dose of selenium (50 mcg Se per day as selenomethionine). Serum selenium was was very low at the beggining of the study and was similar in schoolchildren and in cretins (343 +- 190 nmil/L in schoolchildren, n=23, and 296 +- 116 nmol/L in cretins, n=9). After 2 months of selenium supplementation, the massive decrease in serum T4 in virtually every subject can be seen in fig. 4 below:

In schoolchildren, serum free thyroxin (fT4) decreased from 11.8 +- 6.7 nmol/L to 8.4 +- 4.1 nmol/L (P<0.01); serum reverse triiodothyronine (rT3) decreased from 12.4 +- 11.5 nmol/L to 9.0 +- 7.2 nmol/L; mean serum T3 and mean TSH remained stable. In cretins, serum fT4 remained the same or decreased to an undetectable level in all nine cretins; mean serum T3 decreased from 0.98 +- 0.72 nmol/L to 0.72 +- 0.29 nmol/L, and two cretins who were initially in a normal range of serum  T3 (1.32-2.9 nmol/L) presented T3 values outside the lower limit of normal after selenium supplementation; mean serum TSH increased significantly from 262 mU/L to 363 mU/L (p<0.001).

Another previous similar trial, this time done in 52 schoolchildren, reached the same results: a marked reduction in serum T4 [26][27]. This previous trial “was shown to modify the serum thyroid hormones parameters in clinically euthyroid subjects and to induce a dramatic fall of the already impaired thyroid function in clinically hypothyroid subjects” [27].

What stands out is the difference in the results between euthyroid schoolchildren and cretins/hypothyroids. Two months of selenium supplementation was probably not enough time to affect significantly the thyroid of the euthyroid schoolchildren (althougt already impacted T4 and fT4). But, in cretins and hypothyroids, where the thyroid was already more deficient, the impact was evident.

Conclusion and What I Do

Iodine and selenium are two extremely important minerals for human health, and are righly emphasized as such in the Perfect Health Diet book and blog. I believe they are fundamental to thyroid health and very important to Hashimoto’s patients.

A survey of the literature suggests that Hashimoto’s is largely unaffected by iodine intake. However, the literature may be distorted by three circumstances under which iodine increases may harm, and iodine restriction help, Hashimoto’s patients:

  1. Selenium deficiency causes an intolerance of high iodine.
  2. Iodine intake via seaweed is accompanied by thyrotoxic metals and halides.
  3. Sudden increases in iodine can induce a reactive hypothyroidism.

All three of these negatives can be avoided by supplementing selenium along with iodine, using potassium iodide rather than seaweed as the source of iodine, and increasing iodine intake gradually.

It’s plausible that if iodine were supplemented in this way, then Hashimoto’s patients would experience benefits with little risk of harm. Anecdotally, a number have reported benefits from supplemental iodine.

Other evidence emphasizes the need for balance between iodine and selenium. Just as iodine without selenium can cause hypothyroidism, so too can selenium without iodine. Both are needed for good health.

A few months after I was diagnosed with Hashimoto’s I started 50 mg/day iodine plus 200 mcg/day selenium. If I were starting today, I would follow Paul’s recommendation to start with selenium and a low dose of iodine, and increase the iodine dose slowly. I would not take any kelp, because of potential thyrotoxic contaminants.

Currently I’m doing the following to try to reverse my Hashimoto’s:

  1. PHD diet and follow PHD book and blog advices to enhance immunity against infections, since infections seems to be implicated in Hashimoto’s pathology [28][29][30]. I give special attention to what Chris Masterjohn calls “traditional superfoods”: liver and other organs, bones and marrow, butter and cod liver oil, egg yolks and coconut, because these foods are high in minerals, like iodine, zinc, selenium, copper, chromium, manganese and vanadium, all of which seems to play a role in thyroid health [31];
  2. High dose iodine (50mg of Lugol’s) plus 200 mcg selenium daily. These I supplement because of their vital importance to thyroid and immune function;
  3. 3 mg LDN (low dose naltrexone) every other day to further increase immunity. LDN resources are listed below [32][33][34][35][36];
  4. Avoiding mercury and other endocrine disruptors. When I removed 9 amalgams (mercury), my TPO antibodies increased for 3 months and took another 6 months to return to previous values. I also avoid fish that have high and medium concentrations of mercury. Cod consumption increased my TPO antibodies;
  5. 1g of vitamin C daily. Since it seems to confer some protection against heavy metal thyroid disfunction [37], improve thyroid medication absorption [38] and there is some evidence that it could improve a defective cellular transport for iodine [39];
  6. Donating blood 2 to 3 times per year. In men, high levels of iron seems to impact thyroid function [40].

Final Thanks

I would like to make a special thanks to Paul Jaminet for giving me the opportunity to write this essay, for gathering many, many papers for me, and for having the patience to revise both posts and suggest many changes that made the text clearer; and to Emily Deans who kindly sent me one key study that Paul could not get.


[1] Dr Datis Kharrazian. Iodine and Autoimmune Thyroid — References.

[2] Marino MA et al. Urinary iodine in patients with auto-immune thyroid disorders in Santo André, SP, is comparable to normal controls and has been steady for the last 10 years. Arq Bras Endocrinol Metabol. 2009 Feb;53(1):55-63.

[3] Yoon SJ et al. The effect of iodine restriction on thyroid function in patients with hypothyroidism due to Hashimoto’s thyroiditis. Yonsei Med J. 2003 Apr 30;44(2):227-35.

[4] Kasagi K et al. Effect of iodine restriction on thyroid function in patients with primary hypothyroidism. Thyroid. 2003 Jun;13(6):561-7.

[5] Gribble GW. The natural production of organobromine compounds. Environ Sci Pollut Res Int. 2000 Mar;7(1):37-47.

[6] Zhang ZW et al. Urinary bromide levels probably dependent to intake of foods such as sea algae. Arch Environ Contam Toxicol. 2001 May;40(4):579-84.

[7] Kawai T, Zhang ZW et al. Comparison of urinary bromide levels among people in East Asia, and the effects of dietary intakes of cereals and marine products. Toxicol Lett. 2002 Aug 5;134(1-3):285-93.

[8] Leblanc C et al. Iodine transfers in the coastal marine environment: the key role of brown algae and of their vanadium-dependent haloperoxidase. Biochimie. 2006 Nov;88(11):1773-85.

[9] van Netten C et al. Elemental and radioactive analysis of commercially available seaweed. Sci Total Environ. 2000 Jun 8;255(1-3):169-75.

[10] Hou X et al. Iodine-129 in human thyroids and seaweed in China. Sci Total Environ. 2000 Feb 10;246(2-3):285-91.

[11] Toh Y et al. Isotopic ratio of 129I/127I in seaweed measured by neutron activation analysis with gamma-gamma coincidence. Health Phys. 2002 Jul;83(1):110-3.

[12] Miyashita S, Kaise T. Biological effects and metabolism of arsenic compounds present in seafood products. Shokuhin Eiseigaku Zasshi. 2010;51(3):71-91.

[13] Cleland B et al. Arsenic exposure within the Korean community (United States) based on dietary behavior and arsenic levels in hair, urine, air, and water. Environ Health Perspect. 2009 Apr;117(4):632-8. Epub 2008 Dec 8.

[14] Chong W, Shit Xg, Teng WP, et al. Multifactor analysis of relationship between the biological exposure to iodine and hypothyroidism. Zhongua Yi Za Zhi. 2004 Jul 17:84(14):1171-4.

[15] Tong YJ et al. An epidemiological study on the relationship between selenium and thyroid function in areas with different iodine intake. Zhonghua Yi Xue Za Zhi. 2003 Dec 10;83(23):2036-9.

[16] Karita K et al. Comparison of selenium status between Japanese living in Tokyo and Japanese brazilians in São Paulo, Brazil. Asia Pac J Clin Nutr. 2001;10(3):197-9.

[17] Thorling EB et al. Selenium status in Europe–human data. A multicenter study. Ann Clin Res. 1986;18(1):3-7.

[18] Mengüba? K et al. Selenium status of healthy Turkish children. Biol Trace Elem Res. 1996 Aug;54(2):163-72.

[19] Hincal F. Trace elements in growth: iodine and selenium status of Turkish children. J Trace Elem Med Biol. 2007;21 Suppl 1:40-3.

[20] Fordyce FM et al. Selenium and iodine in soil, rice and drinking water in relation to endemic goitre in Sri Lanka. Sci Total Environ. 2000 Dec 18;263(1-3):127-41.

[21] Alsayed A et al. Excess urinary iodine is associated with autoimmune subclinical hypothyroidism among Egyptian women. Endocr J. 2008 Jul;55(3):601-5. Epub 2008 May 15.

[22] Strieder TG et al. Prediction of progression to overt hypothyroidism or hyperthyroidism in female relatives of patients with autoimmune thyroid disease using the Thyroid Events Amsterdam (THEA) score. Arch Intern Med. 2008 Aug 11;168(15):1657-63.

[23] Stuckey BG et al. Low urinary iodine postpartum is associated with hypothyroid postpartum thyroid dysfunction and predicts long-term hypothyroidism. Clin Endocrinol (Oxf). 2011 May;74(5):631-5. doi: 10.1111/j.1365-2265.2011.03978.x.

[24] American Association of Clinical Endocrinologists Medical Guidelines for Clinical Practice for the Evaluation and Treatment of Hyperthyroidism and Hypothyroidism.

[25] Vanderpas JB et al. Selenium deficiency mitigates hypothyroxinemia in iodine-deficient subjects. Am J Clin Nutr. 1993 Feb;57(2 Suppl):271S-275S.

[26] Contempré B et al. Effect of selenium supplementation on thyroid hormone metabolism in an iodine and selenium deficient population. Clin Endocrinol (Oxf). 1992 Jun;36(6):579-83.

[27] Contempré B et al. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. J Clin Endocrinol Metab. 1991 Jul;73(1):213-5.

[28] Benvenga S et al. Homologies of the thyroid sodium-iodide symporter with bacterial and viral proteins. J Endocrinol Invest. 1999 Jul-Aug;22(7):535-40.

[29] Wasserman EE et al. Infection and thyroid autoimmunity: A seroepidemiologic study of TPOaAb. Autoimmunity. 2009 Aug;42(5):439-46.

[30] Tozzoli R et al. Infections and autoimmune thyroid diseases: parallel detection of antibodies against pathogens with proteomic technology. Autoimmun Rev. 2008 Dec;8(2):112-5.

[31] Neve J. Clinical implications of trace elements in endocrinology. Biol Trace Elem Res. 1992 Jan-Mar;32:173-85.

[32] David Gluck, MD. Low Dose Naltrexone information site.

[33] LDN Yahoo Group.

[34] LDN World Database. Where LDN users share their experience with various diseases.

[35] Those Who Suffer Much Know Much. A colection of LDN users testimonies.

[36] Elaine A. More. The Promise Of Low Dose Naltrexone Therapy: Potential Benefits in Cancer, Autoimmune, Neurological and Infectious Disorder.

[37] Gupta P, Kar A. Role of ascorbic acid in cadmium-induced thyroid dysfunction and lipid peroxidation. J Appl Toxicol. 1998 Sep-Oct;18(5):317-20.

[38] Absorption of thyroid drug levothyroxine improves with vitamin C. The Endocrine Society. News Room.

[39] Abraham, G.E., Brownstein, D.. Evidence that the administration of Vitamin C improves a defective cellular transport mechanism for iodine: A case report. The Original Internist, 12(3):125-130, 2005.

[40] Edwards CQ et al. Thyroid disease in hemochromatosis. Increased incidence in homozygous men. Arch Intern Med. 1983 Oct;143(10):1890-3.

Leave a comment ?


  1. I was a patient and friend for a doc here in Victoria BC, the late Dr. David Derry, who lost his license to practice for suggesting iodine may help in breast cancer.

    Iodine definitely made my Hashimoto’s worse but Dr. Derry saved my life by diagnosing my real condition after four years of torture.

    Don’t depend on endocrinologists. Experiment on yourself until you get it right. And realise that ‘right’ changes over time and you’ll need to fire up the experiment again.

  2. Damned if I do, damned if I don’t!

    Dear Paul, Mario & All,

    This is such valuable work you’re doing! Although I’m enjoying the knowledge base greatly, I’m reading it because I have to.

    My hyperthyroid in 1984 was treated with titrated RAI which destroyed just part of my thyroid. I had 13 years with normal thyroid function and no symptoms.

    By 1997, I had forgotten entirely about my thyroid. So when I started experiencing precisely the same symptoms, I began a round of docs until finally one told me it was all in my head. Five years of undiagnosed suffering. Then a friend came through town and told me it sounded like her thyroid symptoms. She passed me 25mcg T4 tabs and after two weeks I was feeling much more normal.

    I’ve taken 150mcg since then and felt ‘normal’. However this spring thyroid symptoms started again but just periodically. All my lab values are in range for my T4 dose and endos want nothing to do with me.

    I’ve lived in Bangkok for 30 years and finally found Thailand’s only Functional Medicine doc. He told me I could safely add 25mcg T3 to my T4 dose and should test for rT3. Neither med nor test are available in Thailand so I accomplished this on a US visit.

    Here are my results:
    Reverse T3 (rT3) = 19
    Ref:< 15 ng/dl (also expressed as 2
    TPOAb (thyroperoxidase) = 17.24 IU/ml
    Lab ref: <9
    TgAb (thyroglobulin Ab – Iodine) =
    234.81 IU/ml
    Lab ref: <4

    I’m feeling really anxious, sleepless, hot & cold, tingling numb groin, hands & feet.. I’m afraid starting the T3 will make me feel worse.

    Might anyone be able to interpret my results above and has anyone else been in this situation? Are there any other lab values which would help someone answer?

    Doesn’t help my decision mechanism is broken! I know many of you know about that.

    This may be the wrong forum to ask. Apologies if so, and grateful if you point me elsewhere. David Derry was my doc in Canada but his iodine protocol made me more symptomatic. Wish he was still with us.

    Thank you all!

    CJ Hinke
    cj AT tu DOT ac DOT th

    • Hi CJ,

      Generally PHD is good for the thyroid, we have had a lot of testimonials from people who recovered from hypothyroidism (and hyperthyroidism) on PHD. It takes longer to recover from Hashimoto’s than from other forms of hypothyroidism, years instead of 1-2 years which is typical for non-autoimmune hypothyroidism. So you will need patience.

      Problems start in the gut and you have to fix your gut health to start the healing process. Circadian rhythm entrainment, intermittent fasting (with a preference for a feeding window early in the day), good nutritional support including for bile (extracellular matrix, vitamin C), egg yolks, apple cider vinegar, coconut milk, nourishing diet.

      As far as treatment, it sounds like T3 is likely to make you feel better, if you find the right dose and adjust T4 dose downward as you add it. Experiment to find the lowest doses of each that make you feel good.

      Best, Paul

  3. I’m trying to be sure now that I’m following the current supplement recommendations in addition to the diet & i’ve been taking about 15mg lugols iodine (6 drops 2%) per day for about 7 years, plus 200mcg most days of selenium & during the 7 years, i’ve gained about 20 pounds & am now a 42 year old woman. I’m just wondering if my iodine/selenium dosages are the cause. What do you think please Paul? Would you suggest immediately dropping down to the 225mcg daily dose of iodine & 100-200mcg weekly selenium dose? Do you think there will be some new issues I will have to deal with while my body adjusts? Also, it’s possible my copper/zinc was off because I wasn’t eating liver regularly & supplementing zinc daily but not copper. I am going to change that & will take 60mg zinc weekly & 2mg copper daily or eat liver weekly, plus follow all your other supplement recommendations & most of the diet- eat 3 yolks daily etc, except I don’t eat much shellfish. Thank you so much Paul!

    • Hi Holly,

      I believe it’s dangerous to take so much iodine. It can cause thyroid injury and hypothyroidism or hyperthyroidism. Our recommendation is 225 mcg/day iodine (that’s microgram, not milligram). Also it’s generally not necessary or desirable to supplement selenium in the US, as our food (esp PHD food such as eggs, seafood, and beef) tends to be selenium rich.

      Yes, I would drop down to those doses. There could be adjustment issues. It’s not a bad thing to get thyroid labs from your doctor before and after. If there are problems, eat plenty of extracellular matrix (shellfish, soups and stews made with bones/joints/tendons) to support tissue healing.

      Your copper might have been OK if you were eating chocolate, nuts, and seeds. I mostly get my copper from dark chocolate and a few nuts, not supplements.

      Best, Paul

      • Thank you Paul. My husband & I are so grateful we were introduced to you & your book about 5 years ago. The more we adhere to the diet, supplental foods, & supplement recommendations, the better we feel. My husband has only followed your recommendations on supplements including the 225mcg iodine & selenium once a week- he’s more moderate & sensible than me- & at almost 36 he says he feels better & is in better shape than ever in his life! I believe you’re right about the iodine & selenium- that the high dose is harmful & I have a feeling that the issues I’ve had particularly the weight gain is due to the high doses of each of those & regret following Brownstein on those all those years, but am glad I got some sense & figured it out & decided to listen to you on that finally. I think another issue is the butter & MCT oil in coffee in the morning (1T each or more)- see I always regret listening to others! Yours is the most sensible, reasonable plan & if people (myself included) would just listen to you- & ignore the quacks & online misinformation they’d be about in perfect health.

        I made the adjustments yesterday to 225mcg iodine & will stick to your proven plan. Will get back to making bone broth- I do take collagen peptides/gelatin in place of bone broth at times- is that an ok substitute? I’m going to try to start adding in more seafood- just love the grass fed beef so much after years of beans & vegetarian diets before I found PHD- the king of diets! I had been eating 85% chocolate & nuts but had quit those for a while to see if it would affect my weight but it didn’t so i’m adding those back in. What nuts/seeds are most PHD & does it matter if they are raw vs roasted, whole or bought as a nut butter?

        Thanks again for everything Paul. You & Shou-Ching are the best.

        • Hi Holly,

          The commercial products can be an adequate substitute for bone broth. In both cases, be attentive for inflammatory symptoms — if you overcook the bone broth or if the commercial product has been too long in storage, the amino acids can degrade to bioactive amines like histamine and tyramine, causing inflammation.

          The thyroid like other tissues can always heal from injuries or wounds, but it can take some time. Let me know how things go.

          Best, Paul

          • Hey Paul,

            It’s been over 6 weeks now since reducing my iodine & selenium intakes to the levels you recommend- 225 mcg iodine daily & 100-200 mcg selenium weekly. I haven’t lost weight- it’s still between 152-154, but I read one of your posts recently that with PHD you initially gained healthful weight- muscle mass & bone density & I think that’s the case with the majority of my weight gain as well. Since lowering the dosages I’ve been noticing a lot less hair in the shower drain which could indicate the high doses were making me hypothyroid. Also, I had labs & just got the results & my TSH is 80 & T4 is 1.04. A couple years ago my TSH was closer to 2 with the 15mg lugols & 200mcg selenium both daily. Is 1.04 good for T4?

            My total cholesterol is 344, Triglycerides 74 (usually 50 but I think they’re up from trying a bit more carb lately), HDL 106, LDL 223. Do you think I need to do anything to change these numbers or do the low triglycerides coupled with high HDL indicate that my LDL are likely the large, fluffy type & no reason for concern?

            A few items were slightly high:
            RBC 4.9, HGB 15.2, HCT 45.2, Eosinophil .6, EOS 9.2, Magnesium 2.6, B12 1072. Low Alkaline Phospatate- 36. Could this indicate an infection or is it generally normal to be slightly high?

            I’ve tried Creatine Monohydrate 3 times & whether I took 5 grams or just 1-2 grams I had benefit at the gym, but scary side effects & had to quit. I got anxious, tightness in chest, difficulty breathing, irritable/aggressive, insomnia just to name the most serious. Are some people allergic or do you think I have an underlying condition that? I tried Now Foods brand & their Kre-Alkaline & Jarrow CreaPure Pure Creatine Monohydrate. It was pretty scary, but thankfully the chest pain/tightness went away within a week of discontinuing.

            Thank you so much!

          • Hi Holly,

            As you suspected, lowering the iodine and selenium has revealed some thyroid damage and hypothyroidism. This is fairly common after taking large doses of iodine. Sometimes there is hyperthyroidism for a while followed by hypothyroidism. It can take 1-2 years to fully recover, but the biggest improvement should be in the first months. It’s good that you are losing less hair.

            You should see your doctor and ask to be treated for hypothyroidism. People often do better on a mix of T4 and T3, than on T4 alone. Your high LDL and total cholesterol is strongly indicative of hypothyroidism, as is the extremely high TSH. It should be treated, and with proper treatment you should feel much better. Keep in mind however that as you heal, you will need to continually adjust your dose of medication downward. So get tested frequently and try to underdose rather than overdose. Yes, you do need to treat the hypothyroidism that is causing the high LDL, and yes it is a cause for concern independent of the HDL and TG.

            I don’t know why you reacted so badly to creatine monohydrate.

            Best, Paul

          • Hey Paul,

            Thank you so much for your response. Please excuse me- I meant that my TSH is .80 rather than 80, which is the lowest it’s been in years, but do you still think with the high LDL & total cholesterol that I should persue treatment for hypothyroidism? If so, I’ll have to find a new Dr willing to treat because I’m sure my current Dr will say no since my TSH is .80 & my T4 is 1.04. He will say I’m within the ranges.

            A couple years ago my total cholesterol was 275 with triglycerides 55 & HDL 80, but 2-3 months ago I experimented with really high fat keto for about 5 weeks & when it backfired on me (left me feeling exhausted & barely able to complete my usual high intensity workout) I ate too much carb for a few weeks eg a couple pints Ben & Jerry’s a week etc & am just getting back on track with my usual post workout end of fast scoop of plain whey with a little non-gmo dextrose, a scoop or 2 of collagen peptides/gelatin or bone broth, daily intermittent fasting (16-18 hrs) with MCT oil at the end, bibimbap (1/2 cup white rice, 4 oz grass fed beef, 1 cup veggies (broccoli & asparagus gently steamed) & 3 egg yolks for lunch, then meat or seafood, green veggies & 1/2 sweet potato for dinner with butter.

            Perhaps my cholesterol was more elevated due to the extreme experimenting with Keto then high carb for the 2-3 months stint, or is it still more likely to be hypothyroidism as the cause even with the improved TSH of .80?

            Thank you so very much!

          • Hi Holly,

            Oh, that’s better. 0.8 is mildly hyperthyroid, but doesn’t call for treatment.

            Overeating could be a factor in the high cholesterol. LDL will probably normalize on its own. You should try to eat PHD.

            Best, Paul

          • Hey Paul,

            I think you’re right- that my LDL will lower own it’s own & i’ll be fine. Especially if I stay put eating PHD & quit getting off track experimenting. I think my thyroid TSH will only continue to improve since your help in figuring out my excess iodine/selenium supplementation. It’s only been 6 weeks since reducing intakes to PHD recommendations & i’m pleased with the improvements observed like barely any hair loss in shower now!

            I thought I was eating PHD. Does my diet as I described not sound PHD to you? Additionally, I have a sheet of Nori at lunch with my bibimbap, beef liver, salmon & shellfish (shrimp or scallops) weekly. Snacks are 85% dark chocolate, almond butter & full fat grass milk Greek yogurt & I have a cocktail in the evening – 1 ounce Hendricks gin with sparkling mineral water & juice of a lemon or lime. I drink a bottle or 2 of mineral water daily & take the recommended daily & weekly supplements- now at the proper dosages for all. I do limit my carb to white sushi rice at lunch, 1/2 sweet potato at dinner & a little dextrose in my post workout whey. I feel best when I do. When I experiment with adding more carb eg fruits I don’t feel as good. I do best with starch/glucose for carb. I also tolerate some raw honey as a sweetener, & occasionally berries. I feel best when I avoid all fructose including most fruits except lemons & limes. Although I have gained about 15-20 pounds since going PHD/Paleo about 5 years ago- I’m not overweight at all. I’m 5’7” 152-154 lbs & have much more muscle mass & i’m sure bone density as well.

            Is there anything else I could do to be more PHD that stands out to you, besides stopping my going off & experimenting from time to time? I also sunbathe 30 minutes daily & exercise- weights & cardio 4-6 days a week, daily intermittent fasting & circadian rhythm entrainment including wearing my blue blockers at night & using amber lights at night which by the way pretty much cured my insomnia- so again thank you. PHD has been the best thing for both my husband & me. So grateful.

            Thanks again!

          • Oh & I believe you’re also on to something else- as far as my high LDL possibly being related to overeating. Aha, this is very possible as have basically starved & malnurished myself & my dear husband with years of a low fat high carb vegan/vegetarian diet before discovering PHD- I want to be sure i’m Extra nourished now & I absolutely love eating & love PHD foods. Real food! Even though I workout sometimes for 2 hours a day at high intensity, i’m Definitely rarely hungry & probably do overeat. I eat almost the same amounts as my 6’ 200lbs husband.

            Again I can’t thank you enough. PHD changed our lives for the better. We feel better. We’re not hungry. We’re think better. Our brains work better, we’re happier, & we even got back into going to church- discovered the Greek Orthodox Church & love it. Diet is so important & impactful.

            You’re a smart cookie.

      • If some damage has been done to my thyroid from the years of high dose iodine/selenium, can the thyroid recover now that I have stopped the high doses?

        • Holly, can I ask bow you prepare the eggs yolks. I follow the PHD and eat three egg yolks a day. I fry my eggs and then throw away the white part.

          • Hey Gina,

            I just gently boil a dozen eggs at a time. As soon as the water covering the eggs reaches a gentle boil, I remove from heat & let sit (with lid kept on) for about 6 minutes & then immediately transfer to a bowl of ice water so they don’t continue cooking. I like the yolks to be slightly soft. Taste better & healthier. I take 3 out of fridge each day & discard the whites. Soft boil is a gentler method than frying & more efficient since you can cook enough to last a few days as Paul suggests with rice, potatoes & broth.

      • Hi Paul,

        I hope you’ll consider changing the author’s recommendations in the above article, as some might not see the more recent comments where you recommend a LOT less iodine, and no selenium supplementation.

  4. Important Update on Selenium Supplementation | Chris Kresser - pingback on June 18, 2019 at 1:06 pm
  5. Paul,

    It’s been roughly 8 years since you published this post. Did the PHD, iodine, selenium, and other points mentioned in the “Conclusion and What I Do” lower your anti-bodies and return you to a euthyroid state?

    I too have elevated anti-bodies and was diagnosed with Hashimotos. I recently came across the work of Dr. Brownstein (he advocates 12-50mg/day iodine supplementation) and while his research is persuasive, case-reports and case-studies of actual lab numbers are few and far between.



    • Hi John,

      This was a guest post by Mario Renato Iwakura, who had Hashimoto’s. I never had Hashimoto’s, so far as I know (I was hypothyroid for a time, but am euthyroid now). I am not sure how Mario is doing today.

      I think Dr. Brownstein’s iodine recommendation is excessive and risky. I favor a daily dose of iodine below 1 mg, preferably in the 150 mcg – 225 mcg range, or regular seaweed and seafood consumption.

      We had enough experience with hypothyroidism among readers and retreat guests to be confident that high doses of iodine are, indeed, risky, and that PHD advice consistently improves and/or cures hypothyroidism.

      Best, Paul

  6. I don’t think the recommendation of avoiding selenium without sufficient iodine holds much truth. It may very well ameliorate hypothyrodism. The group that studied this phenomenon published three articles between 1991 and 1993. In the discussion section of the last article from 1993 (reference 27, from which the graph was taken), clearly states that: “in schoolchildren after selenium supplementation, the lowering of T4 is not accompanied by a decrease in T3; it is not evident, then, that the aggravation of hypothyroxinemia means an aggravation of hypothyrodism, at least for a few months; a better intracellular conversion of T4 to T3 could even mitigate hypothyrodism, as the decrease in serum TSH after selenium supplementation in initially hypothyroxinemic children suggests.” They only saw negative results in cretins, aka extremely iodine deficient children with a serum T4 <20 nmol/L. I don't think cretinism is a problem at all nowadays in western countries…

  7. Meet your Thyroid: a Paleo Introduction | Paleo Leap - pingback on January 25, 2023 at 3:29 am

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