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:
- Selenium deficiency causes an intolerance of high iodine.
- Iodine intake via seaweed is accompanied by thyrotoxic metals and halides.
- 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:
- 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];
- 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 mg LDN (low dose naltrexone) every other day to further increase immunity. LDN resources are listed below [32][33][34][35][36];
- 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;
- 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];
- 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.
References:
[1] Dr Datis Kharrazian. Iodine and Autoimmune Thyroid — References. http://drknews.com/some-studies-on-iodine-and-autoimmune-thyroid-disease/.
[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. http://pmid.us/19347186.
[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. http://pmid.us/12728462.
[4] Kasagi K et al. Effect of iodine restriction on thyroid function in patients with primary hypothyroidism. Thyroid. 2003 Jun;13(6):561-7. http://pmid.us/12930600.
[5] Gribble GW. The natural production of organobromine compounds. Environ Sci Pollut Res Int. 2000 Mar;7(1):37-47. http://pmid.us/19153837.
[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. http://pmid.us/11525503.
[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. http://pmid.us/12191890.
[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. http://pmid.us/17007992.
[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. http://pmid.us/10898404.
[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. http://pmid.us/10696729.
[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. http://pmid.us/12075675.
[12] Miyashita S, Kaise T. Biological effects and metabolism of arsenic compounds present in seafood products. Shokuhin Eiseigaku Zasshi. 2010;51(3):71-91. http://pmid.us/20595788.
[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. http://pmid.us/19440504.
[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. http://pmid.us/15387978.
[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. http://pmid.us/14703411.
[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. http://pmid.us/11708308.
[17] Thorling EB et al. Selenium status in Europe–human data. A multicenter study. Ann Clin Res. 1986;18(1):3-7. http://pmid.us/3717869.
[18] Mengüba? K et al. Selenium status of healthy Turkish children. Biol Trace Elem Res. 1996 Aug;54(2):163-72. http://pmid.us/8886316.
[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. http://pmid.us/18039495.
[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. http://pmid.us/11194147.
[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. http://pmid.us/18480555.
[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. http://pmid.us/18695079.
[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. http://pmid.us/21470286.
[24] American Association of Clinical Endocrinologists Medical Guidelines for Clinical Practice for the Evaluation and Treatment of Hyperthyroidism and Hypothyroidism. https://www.aace.com/sites/default/files/hypo_hyper.pdf.
[25] Vanderpas JB et al. Selenium deficiency mitigates hypothyroxinemia in iodine-deficient subjects. Am J Clin Nutr. 1993 Feb;57(2 Suppl):271S-275S. http://pmid.us/8427203.
[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. http://pmid.us/1424183.
[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. http://pmid.us/2045471.
[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. http://pmid.us/10475151.
[29] Wasserman EE et al. Infection and thyroid autoimmunity: A seroepidemiologic study of TPOaAb. Autoimmunity. 2009 Aug;42(5):439-46. http://pmid.us/19811261.
[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. http://pmid.us/18700170.
[31] Neve J. Clinical implications of trace elements in endocrinology. Biol Trace Elem Res. 1992 Jan-Mar;32:173-85. http://pmid.us/1375054.
[32] David Gluck, MD. Low Dose Naltrexone information site. http://www.lowdosenaltrexone.org/.
[33] LDN Yahoo Group. http://groups.yahoo.com/group/lowdosenaltrexone/.
[34] LDN World Database. Where LDN users share their experience with various diseases. http://www.ldndatabase.com/.
[35] Those Who Suffer Much Know Much. A colection of LDN users testimonies. http://www.ldnresearchtrustfiles.co.uk/docs/2010.pdf.
[36] Elaine A. More. The Promise Of Low Dose Naltrexone Therapy: Potential Benefits in Cancer, Autoimmune, Neurological and Infectious Disorder. http://www.amazon.com/Promise-Low-Dose-Naltrexone-Therapy/dp/0786437154.
[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. http://pmid.us/9804431.
[38] Absorption of thyroid drug levothyroxine improves with vitamin C. The Endocrine Society. News Room. http://www.endo-society.org/media/ENDO-08/research/Absorption-of-thyroid-drug.cfm.
[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. http://www.optimox.com/pics/Iodine/IOD-11/IOD_11.htm.
[40] Edwards CQ et al. Thyroid disease in hemochromatosis. Increased incidence in homozygous men. Arch Intern Med. 1983 Oct;143(10):1890-3. http://pmid.us/6625774.
via this link:
Excellent articles!
Just like “the dose makes the poison”, the more I read about nutrients, maybe a phrase like “they work in synergy” seems to apply.
Speaking of applying, how does this apply to those with assumed normal thyroids?
Should everyone taking the iodine the first time slowly build up?
Could you elaborate on naltrexone?
I’m conflicted with natural food supplements. On the one hand, the conclusion remarks of the benefits of cod liver oil but then warns against kelp, which is also a WAPF suggested food supplement. Is contaminants enough of a concern in all food supplements and makes synthetic safer?
Hi Jaybird,
Those with normal thyroids should optimize their selenium status – I think around 300-400 mcg from all sources is close to optimal, and a 200 mcg supplement plus food would be in that range, with or without 50 mcg from a multi. So you could find a multi with 200 mcg like the one Chris recommends, or take a lower-selenium multi like we do and supplement selenium in addition.
Then, I would recommend supplementing iodine as well, in order to drive out competitors like bromine and avoid any deficiency conditions.
Yes, everyone should build up slowly. Start iodine low and no more than a doubling per month. This is especially true for those with healthy thyroids.
Naltrexone – it blocks opioid receptors and upregulates the natural ligands of those receptors, which are immune compounds. Upregulating these compounds modulates immune function and aids against certain diseases, notably cancer and autoimmune diseases. It can help against some infections but hurt against others. I will do a post or series on it with more details.
The last question is hard to give a definite answer to. I prefer synthetic for selenium because it has a narrow window before toxicity begins and I like better control of the dose. Also for iodine because of potential toxins in kelp. But natural is likely to be better for many nutrients. Some nutrients, like vitamin E or carotenoids, come in many varieties and the natural mix is much healthier than a high dose of only one variety such as is found in supplements. In others, like folic acid vs folate, the synthetic version is different than the natural form.
Best, Paul
Thanks Paul. Informative as usual.
This iodine information as well as in the PHD book has been a real eye opener since not many if at all of the few dozen health diet books I’ve read even mention it.
I assume I have a normal thyroid and not an issue, but my ears still perk up on the topic when my mother, who died of breast cancer, always claimed she had thyroid problems. I know she wasn’t taking any extra selenium and iodine, yet she saw specialists for it.
Also, may I suggest a future series of articles on this synthetic vs. natural supplements. I think for most amateurs out there getting healthy becomes overwhelming to even start because the supplement field is as confusing as figuring out what the right diet is. Yet, I find a fraction of the thorough articles on supplements on blogs and books as one can with food and diet. Then, your faced with the expensive cost of the supplements. Most is obviously just peddled from biased sources of course. After reading articles like this on iodine and PHD book, it sure makes deciding a lot easier coming from people like yourself Paul whom I know at least got the diet part right, instead of the vitamin and mineral book I read recently that ends a section on a vitamin’s food sources saying, “So just another reason to eat more whole grains!”
Hallo Mario,
thanks for the post. I have also Hashimoto. Could you say how you are doing right now? How are your free t4 and free t3 levels? And how did they change since you’ve started with iodine? Do you take hormones? Thanks!
Best, Pia
Hi Pia,
I’m doing great. I’m not exactly a model of a Hashimoto’s patient, since I did/do not have any symptoms at all.
My free t4 and free t3 are in range. Currently, I’m taking 1 1/2 grain of Thyroid-s from Thailand and, at this dose, my TSH is really low, last time the laboratory could not measure, was lower than 0.05.
Two years ago, when I was diagnosed, my TSH was 13.3. When I started Lugol’s (50 mg/day), my TSH jumped to 26.7 and four months later decreased to 0.53. Not much change in free T4 or free T3 during this period.
For people with normal thyroid status, what would you recommend for an average iodine intake? Is this data in your book? whfoods.com lists 150mcg as an RDI for men over 19, and 1,100mcg as the tolerable upper dose for the same. Do you think these recommendations are about right?
Many thanks to both Paul and Mario for efforts both past and present to shine a light on subjects that sorely need it.
Hi Andrea,
I don’t have a specific dose. In extreme cases, some people have found it takes them a year at 50 mg/day to clear their system of bromine. That’s almost 20 g total iodine. It might take them 50 years to do that at 1 mg/day. So high doses might be necessary for some people to achieve the full benefits of iodine on a reasonable time scale.
On the other hand, the higher the dose the more the risk of something going wrong. As far as thyroid function goes, I’d say that barring bromine or other competitors, the thyroid will do quite well on 1 mg/day. I would consider 1 mg/day a healthy and low-risk choice.
But there can be benefits to going higher. Iodine has a role in immunity and I think the optimum for immune function is higher.
Expense is another consideration, since iodine can be expensive.
I personally take 12.5 mg/day, an Iodoral tablet.
There’s so little data on high-dose iodine supplementation that I would recommend you experiment and try to find a dose that you think works best for you.
I would just suggest to start low and never change dose by more than a factor of 2 in either direction per month. The thyroid typically takes 3-4 weeks to adjust to an altered dose.
Best, Paul
Do you still take 12.5 mg a day? I’m confused because I thought you only recommended 225mcg a day. I’ve been taking about 15mg a day for several years & was going to try reducing to 225mcg based on your recommendation.
No, we recommend 225 mcg/day.
I keep reading about the dangers of iodine from kelp tablets. If I take even a supposed high quality kelp tablet (say from life extension which conveniently bundles 1mg iodine from kelp, 5kiu D3 and both forms of K2(mk4/7) at ~1mg) do I have to worry about the impurities of the kelp??
In other words, should I rather seek iodoral or lugols?
I wonder if it’s even possible to recover from hypothyrodism just by following a healthy diet and take several supplements,
If not and thyroid meds are needed why do you need to supplement with Iodine as well?
Hi Chris,
I wouldn’t go above 1 mg/day with kelp.
Hi Danny,
Sometimes it’s possible to cure hypothyroidism with diet and nutrition. Other times there’s an underlying cause, like a chronic infection, that has to be cleared first. It almost always takes time.
It’s better to use more iodine and less thyroid medication, since your body manages hormones in a complex way that supplements don’t completely replicate. Also, iodine has other uses besides making thyroid hormone.
For example, Bill mentioned elsewhere that supplementing 50 mg/day iodine dropped his requirement for thyroid hormone in half. See http://perfecthealthdiet.com/?page_id=1066#comment-23425. I think that’s a clear positive.
Best, Paul
Mario, Did you start taking the Thyroid-S after or before starting the iodine? Do you feel iodine helps with reducing the needed dose of Thryoid-S? Why do you prefer this brand to others? Are the various additives listed below not a concern to you?
http://www.stopthethyroidmadness.com/armour-vs-other-brands/
Excellent posts. Thank you Mario!
Great to know about the Kelp concerns. I have worked up gradually with the kelp (240mcg per tablet). Started at one tablet, now up to 8 (1.9 mg – over several months). I now see this is too much kelp. I do have iodine tablets that are 12.5 mg each. How should I go from here? If I quarter them that would still be a jump up to 3.1 mg. Thoughts?
Also, my selenium tabs are 150 mg each. I am currently taking one. Thoughts on increasing to 2?
Background – 100% strict paleo / PHD X 5 yrs. Nil thyroid concerns. 47 y/o male.
Mario – did you get hypothyroid symptoms and gain weight when you started taking high dose iodine, and were you taking thyroid supplement at the same time?
Hi Jeff,
150 mcg selenium is fine, especially if you are taking a multi which may have 50 mcg selenium also.
I find the Iodoral tablets easy to quarter, but it’s hard to control the size if you cut them to eighths. Still, that’s a possibility. I doubt a little variability would be that harmful.
I’ve put up on the recommended supplements page some 3 mg iodine tablets, those can easily be halved for a 1.5 mg dose.
Jeremy,
When I started Lugol’s I was taking levothyroxine (100 mcg). A couple of months later, I started taking 2 grains of Thyroid-s. About 8 months later, I had to reduce my dose to 1 1/2 grains, because in some days was getting tachycardia.
Regarding Thyroid-s versus other brands, it’s simple a question of what is easier and cheaper to me to get, because importing medicine from, say, US, is a lot more dificult and expensive. Addictives are allways a concern, but until now I’m doing fine and I expect to be off it sometime in the future, since my Hashimoto’s was only subclinical when I was diagnosed.
Mia,
Thanks!
Jeff,
I think that the easiest way is to buy some Lugol’s, say 5%, and dilute to something around 0.5%. This way, each drop will give you around 0.65 mg of iodine, and 3 drops will give your actual dose.
Juliane,
No, I did not feel a thing, bad or good, when I started taking high dose of iodine. The only thing I notice was an increase of body temperature.
Thanks for your 2 great articles Mario
I have tried supplementing with iodine (potassium iodide) in very small doses, started at 150mcg p/d & peaked at 435mcg p/d. But i get a hyper type reaction (throat feels a bit swollen & sensitive, feels like i have a lump in my throat when i swallow etc, sleep may have got worse as well). In hindsight these symptoms started even at the low dose, but i thought the ‘sore throat’ was just a coincidence. When i stopped the iodine the symptoms went away.
So i am guessing that i may be deficient in selenium &/or copper. I have started supping both of these, but from memory i think i started the iodine first.
My question; Is it safe to have a daily Selenium intake (food & supps) of between 200mcg & 400mcg Without iodine supplementation?
If i’m reading some of the studies above correctly, the answer is going to be a bit more then a simple yes or no.
Darrin,
Your symptoms seems to be bromide detox. See the link below:
http://breastcancerchoices.org/bromidedetoxsymptomsandstrategies.html
I would not do selenium supplements without knowing my iodine status.
I have hashimoto. I take 50 grams of grass fed lamb kidney (Asumming it to be 100mcg) and I am consuming iodized salt regularly. Do you think it to be ok for my thyroid? I am avoiding iodine and selenium supplements (don’t want to take any risk as my TPOab is within limit).
I tried iodine before too, and like Darrin got a burn/sore throat reaction. it was potassium iodine, and a small dose
Hi Vizeet,
Yes, iodized salt should be good for you, and the lamb kidney. I don’t think you need to totally avoid iodine and selenium supplements, but I understand your caution.
Info about low dose naltrexone can be found at these two non-commercial sites edited by David Gluck, MD, with other contributing MDs and PhDs.
http://www.lowdosenaltrexone.org/
http://www.ldninfo.org/
Mario – you noted that selenium status in Japanese living in Japan is better than for Japanese living in brazil. Do you have information on the selenium status in Japan, since it was in that population hashimoto’s was first identified? Thanks, Peter
Fascinating article. How would one determine if selenium exists in excess (serum, tissue, saliva, urine)? What are optimal ranges? If an excess is present, how would you lower it?
What are your thoughts on the proper diagnosis of Hashis? Just the mere presence of antibodies constitutes a diagnosis, or do the ranges have to exceed that upper limits on labs? Do ALL people have a certain amount of antibodies present at all times?
Miriam,
For selenium, I think it’s best to you to read PHD book…
Thyroid autoantibodies have to exceed some upper limits to constitute a diagnosis of Hashi. Do all people have a certain amount of antibodies present all times? Certanly not, even some Hashi patients does not have thyroid antibodies at a level that can be measured all the times. Immune system sometimes fluctuates, so the production of antibodies. But, if, someone, ever, tested high for thyroid antibodies, that means that this person undeniably has Hashi.
Best,
Mario.
Thank you Mario,
How do you interpret labs which give antibody values as values? For example:
thyroglobulin antibodies <20, ref. range <20 IU/mL
How meaningful is a lab value like this, and is that a diagnosis of Hashimotos?
Miriam
Miriam,
This lab value is saying that your thyroglobulin antibodies is low, below normal reference range. How that could diagnosis Hashimoto’s?
It’s not even the most meaningful antibody in Hashimoto’s, it is present in around 60% of Hashimoto’s patients. On the other side, thyroid peroxidase antibodies (TPOAb) are present in around 95% of persons with Hashimoto’s thiroiditis.
http://thyroid.about.com/od/gettestedanddiagnosed/a/bloodtests.htm
Why are you concerned about Hashimoto’s? Do you have any symptoms?
I have episodes of a really sore tender thyroid (having one right now) and I seem to be able to coorelate it with iodine supplementation. I have done the iodine loading test and I am deficient. My hair analysis shows my selenium dead smack in the middle of the ideal range. Hence my original question – the best way to measure selenium levels.
My TPOAb antibodies are even lower
<10 ref range <20
The above ranges I'm giving you were from the last episode of swollen thyroid, it was visibly swollen, tsh 8, t4 1, ft3 230. I would think if the antibodies were going to go up, it would have been then.
Hence the puzzle: is it Hashi's or not?
Hi Miriam,
It’s not Hashimoto’s. Could just be iodine deficiency. Other possible factors include iron or copper deficiency and infection.
It’s common for the thyroid to enlarge and become tender for several weeks when iodine intake increases, especially from a deficiency condition. If you increase iodine dose very slowly, that will help you avoid trouble.
Do you take a multivitamin? That would be a good starting point.
Best, Paul
Aha. I just keep going back to the IRON.
I’m having a horrible time getting the ferritin to go up and stay up – in 2009 the lab couldn’t even measure it. Two years later I’m at a whopping 25. I take multi vitamin – yes.
Does iron have a direct affect on iodine? Or are you saying an iron deficiency can cause the thyroid to swell?
I really appreciate all of your help. My doctor can’t figure me out and is ready to put me on the front step. 🙁
miriam
Hi Miriam,
Well, your situation — hypothyroidism, iron deficiency, goiter — is a fairly common pattern. See e.g. http://www.ncbi.nlm.nih.gov/pubmed/21321427 (full text: http://www.ijmr.org.in/article.asp?issn=0971-5916;year=2011;volume=133;issue=1;spage=103;epage=109;aulast=Das)
Yes, I am saying an iron deficiency can cause the thyroid to swell. Here’s another relevant review paper – iron deficiency can exacerbate an iodine deficiency: http://www.ncbi.nlm.nih.gov/pubmed/19594417.
You should read this post: Micronutrient Deficiencies: An Underappreciated Cause of Hypothyroidism, http://perfecthealthdiet.com/?p=1272.
There are many possible causes of iron deficiency. Here is a review: http://www.ncbi.nlm.nih.gov/pubmed/21067951. One possible cause is copper deficiency, which also causes hypothyroidism, see the above post.
Your doctor should be looking into the cause of the iron deficiency. Do you have symptoms of chronic infection?
Candida infection – ready to bang my head against the wall on that one.
I had bad reaction to sinus surgery (chronic infections) about 5 years ago in which I lost a BOAT load of blood – it was right after 2 pregnancies and 4 years breastfeeding. I was seen by a hematologist who told me I was ok and didn’t tell me to take iron. growl.
Copper was low on hair analysis: 1.1 range:.9-3.9
For your research on this article, here are my antibodies before and after iodoral:
4/30/2009: no thyroid meds, no iodine
TPOAb <10 ref <35 IU/mL
Tgab <20 ref <20 IU
6/10/2010: w/ thryoid meds + iodoral 25 mg
TPOAb <10 ref <35 IU/mL
Tgab <20 ref <20 IU
selenium: .12 ref .03-.18
I will check out your links.
Hi Miriam,
I’ll be doing some posts on Candida this summer.
Until there is an indication that it’s counterproductive, I would supplement iron and copper to try to get levels higher. 2 mg/day copper, or beef liver once a week.
At the same time your doctor should be chasing possible causes of the iron deficiency.
After iron and copper are in better shape, then I’d try iodine, starting very low and increasing very slowly.
I’ll be picking up copper right away.
Looking forward to the Candida posts!
m
Wow! Thank you Mario for this wonderful post. That hemochromatosis paper is very interesting too.
I am so confused and don’t know where else to go. I think I have to find a new Dr. and don’t know where to find a good one.
At my heaviest in May 2010 I started a diet called Ideal Protein and lost 45 pounds in 3 months and then the weight loss stopped. I switched over to Primal eating the first of this year. I still have not lost any weight despite the fact I eat around 1,500 calories daily and do kickboxing 3 times a week and P90X 2-3 times a week also. I still have 30 pounds to lose.
I am gluten and dairy free. I found out a year ago after doing a stool test that I am allergic to casein. I did the stool test because I was having a lot of bloating and heartburn.
I also did a saliva test in Aug. 2010 that showed I had depressed adrenal function and low progesterone (23) I am 39 with 3 kids and started my period at age 9.
In Sept. 2010 the Dr. told me to take a 1/2 tab of Iodoral a day for a week and then a full tab every day. I can’t say I did or did not notice any symptoms then or not. Honestly that is my busiest time of year for work and I just went on with life. In March of this year I felt like I was always coming down with something like a head cold, sore throat, and slight drainage. After a few days of not taking any supplements I noticed it pretty much went away. So I added everything back one by one and sure enough it was the Iodoral. So I stopped taking it. I also started to have breakthrough bleeding in the middle of my cycle. I did not have it this past cycle though. Dr. did put me on Wild Yam Complex for this though.
Which brings me to now. Twenty days after having stopped the Iodoral I had a bloodwork panel done and I don’t think I asked for all the correct thyroid tests anyway but here are my results:
Free Thyroxine .89 (.60-1.50)
Triiodothyronine 87 (60-200)
TSH 3.20 (.36-3.74)
T3 Reverse 234 (90-350)
Thyroglobulin 130 (1.7-56) This one scares me to death because I looked it up and now I think I am giving myself panic attacks. Dr. said to test it again in a year.
TGab <20 (0-40)
TPOab 12 (0-34)
I am utterly confused about where to go from here. Dr. said something about putting me on thyroid hormone but I am not sure I want to rush into anything and this is the same Dr. who neglected to tell me that I was supposed to keep taking the adren-all the entire time I was taking the Iodoral.
I just started taking a multi-vitamin Nature's Way Alive but it does not have Iron and I am wondering if I need an iron supplement. I eat alot of grass fed beef.
I take several other supplements and just started the K-2 and Selenium a few days ago after reading your book.
I also would like to add that I quit smoking a bit over two years ago and gained that 45 pounds that I lost but I never lost my weight after my last two babies (the youngest of which is 8) However, I know this sounds stupid but smoking helped me relax and I think that is when all this adrenal trouble started.
I am sorry this is so long. I just feel that I am at my wits end and am so overwhelmed with conflicting information. I am crying typing this up. I just want answers and I want to do the right thing.
Hi Traci,
You’ve done a good job figuring out the problem. That’s always a crucial first step.
Sometimes the best therapy is just to quit making mistakes and give your body time to heal. That way, we know which problems are lasting and which are due to too much iodine with too little selenium or some other problem you’ve already remedied. A good diet and nutrition may help.
You should have an idea of your iron status. It’s a good idea to get a multi with iron, since you’re menstruating. You can ask your doctor to test ferritin level. Do you have any signs of anemia?
Vitamin D (serum 25OHD) is another helpful thing to know, especially when you’ve been getting colds in late winter / early spring.
It’s good that your antibody counts are low. That rules out many problems and suggests a good diet and nutrition may fix things.
I don’t think you should be worried about the high thyroglobulin. Excess iodine and low selenium will elevate thyroglobulin, that is how the thyroid protects itself from excess iodine if it can’t process it with selenium enzymes. See, eg, http://www.ncbi.nlm.nih.gov/pubmed/10537174. Correct the nutrients and thyroglobulin will probably come back to normal. Same with rT3.
I think it would be best to not worry too much about weight until you fix diet and nutrition and the thyroid and adrenal situations are sorted out. Very likely weight loss will resume in a month or two as the thyroid situation heals.
Thyroid hormone may help you if the thyroid doesn’t fix itself in a month or two.
We recommend a systematic approach to healing that begins with optimizing diet and nutrition. Patience is your friend, because ultimately your body has to heal itself. Primal is a good diet so your diet probably needs only minor tweaks. Better supplementation will probably clear some symptoms. Let me know what symptoms remain in a month or two.
Best, Paul
PS – You might be careful about overtraining. 6 workouts a week, 3 P90x, is pretty intense, especially if your job is intense and you are hypothyroid. Sometimes rest is helpful for healing. Walking in the sunshine might be a good alternative.
Traci- I agree w/ Paul. It really sounds like you’re over-training. If I were you, I’d cut what you’re doing in half and throw some walking in there if you feel like you’re not getting enough activity in (even though you are) 🙂
Traci,
“In March of this year I felt like I was always coming down with something like a head cold, sore throat, and slight drainage. After a few days of not taking any supplements I noticed it pretty much went away. So I added everything back one by one and sure enough it was the Iodoral.”
Those problems could be a result of detoxing bromine, which is driven from tissues by iodine. When I increased my Iorodal to 50 mg per day (after learning I was extraordinarily toxic in bromine), I experienced similar symptoms. I thought I was getting sick, which concerned me because since I started supplementing vitamin D years ago that hasn’t happened even once. It is now pretty clear that my symptoms were caused by sinus drainage, a common feature of bromine detox. The symptoms all went away when I added 1 teaspoon of Celtic salt per day to my regimen.
I agree with Paul that supplementing iodine without selenium can cause problems. I think that anyone experimenting with iodine should follow the complete, holistic nutritional program recommended by all of the experienced iodine doctors. This is the protocol that has proven so safe and effective for a great variety of problems, with thousands of patients having been followed now for years. One authoritative source on this protocol is:
http://f1.grp.yahoofs.com/v1/QHvnTV14aqrKQifxbnhHod_olEGmQd7pg6en1V7d88E3OCwrWShKZYDsVdjWYbDGdkDqzES5j5DtLgNtcFByCb2crpxBGvRdUF0/01%20NEW%20MEMBERS%20-%20READ%20FIRST/01%20-%20New%20Member%20Iodine%20Q%20and%20A.doc
Your bloodwork suggests that you are mildly hypothyroid. That could explain the adrenal problems I think. Iodine could eliminate the hypothyroidism, but either way you may benefit tremendously from thyroid medication.
Bill, I also have sinus drainage problems which have defied the ministrations of half a dozen ENT’s over the past almost 20 years. I thought I’d give up trying to get help, but the chronic headaches are so annoying I’m almost ready to try another new doctor, but if switching to Celtic salt would do the trick, I’d sure rather do that than start another round of tests and trials.
Do you take a teaspoon of Celtic salt in water all at one time or do you use it as your general salt source?
I take Paul’s suggested supplements with half an Iodoral tablet. I’ll ratchet that up to a whole tablet when I return from a planned trip later this month. Since following the PHD, doing moderate exercise and walking two miles a day, my weight is pretty good. I’ve stopped BP medication totally and I plan to stop HRT later this month as well. Bloating and gas have been greatly reduced and I feel well.
General joint pain and stiffness haven’t improved much, but I’m thinking this is due to past bad nutrition and wear and tear, so if this is as good as it gets, I can handle it.
Thanks to our hosts for their outstanding work and the great comments from fellow readers.
Paul,
Thank you so much for your response. I will have my iron levels checked. I haven’t taken any supplemental iron since I was pregnant and my youngest is 8.
I did have my Vitamin D level checked it is 46. Since I started taking vitamin D a few years ago I rarely get sick which is one reason the sore throat and head cold feeling which weren’t alleviated by vit d confused me. The funny thing is though I still have a bit of drainage and scratchy throat (nothing like when I was taking an Iodoral pill daily) I experimented with Claritin and after taking it a few days the drainage and sore throat go away. If I don’t take it a few days it comes back. So I am wondering if I have an allergy also. The Nature’s Way Alive multi I am taking had 150 mcg of iodine in it. You don’t think I could possibly be having a reaction to that low of an amount do you?
I am trying to be patient. Honestly I am, but after a year of eating proper, not eating gluten and casein and exercising it is frustrating to see no progress on the scale. Unfortunately I am not even seeing inches lost either.
I just started taking the adren-all again and ordered some nettle seeds which I intend to try to help with stress. They are supposed to be an excellent adaptogen. I am willing to try anything at this point. I always feel so “nervous” or anxious and am really high strung and I don’t know why (my mom is the same way)
I know everyone says I should not be exercising so much or so hard but I feel it really helps me with stress and I am scared to death of regaining the weight I lost. I was thin my whole life until I had my children. I lost all of my weight after my first pregnancy but after my second I was so busy and nursing and got pregnant again in 8 months and just never lost that 30 pounds. I want to be a good role model for my children(all 3 of them do kickboxing with me) when it comes to diet and exercise so they hopefully never have to endure all of this. I did have my daughter tested for food allergies and she has the anti-bodies to gluten. I want to have my other 2 tested as well but since insurance does not cover it I have to do one at a time and I suspected her to have it.
@Ellen, I will consider possibly stopping the P90X in exchange for walking until I get this worked out but I do kickboxing with my kids and I really enjoy this time with them. I work from home so I am able to stand and not sit all day.
@Bill, that link is not working and I would love to take a look at that. I will have to look into checking on the bromine levels. I mentioned something to my Dr. about and Iodine loading test and he thought I was crazy! Unfortunately where I live it is hard to find a Dr. that thinks like me.
I did want to mention that we eat 90% organic. I have been a CSA member for 6 years and all our meat and eggs are purchased locally, free range, organic and pasture raised so I am getting the most from what I eat.
Thank you once again to everyone who has commented and tried to help me. You truly do not know how much it means to me and puts me at ease 🙂
Traci, sorry about the broken link. I converted the file into a PDF and hosted it myself:
http://public.myjungledisk.com/84AZ9XAF8X88457Z/Yahoo
It’s the new member Q&A from the Yahoo iodine group. I believe it reflects the current practice of Dr. David Brownstein and the other iodine doctors.
If you want to, you can get an iodine loading test yourself, as explained in the Q&A. You could also ask your doctor for a serum bromine test.
erp, I take 1 teaspoon of Celtic salt mixed in warm water once a day, and I use Celtic salt (via a grinder) liberally to salt my food as well. That relieved my sinus detox symptoms very quickly, and my bromine level seems to be dropping nicely.There is also a salt loading procedure you can use temporarily in addition if needed. This is described in the Q&A I linked to above.
Of course, I’m sure there are plenty of other possible causes of your symptoms. But this is what mine turned out to be, and it’s apparently quite common after beginning, or upping the dose of, iodine.
Bill, I just received 2 of Dr. Brownstein’s books in the mail today! The Iodine one and the thyroid one. I will take a look at the link and read his books.
I don’t know why but I forgot to mention in my previous posts that when I did the stool test in addition to discovering I had casein anti-bodies they also said I had H. pylori and entamoeba hystolytica. The Dr. put me on Flagyl, some anti-acid and Pepto bismol to get rid of it. I also took some Mastic gum for the h. plylori and after reading Dr. Elizabeth Lipski book “Digestive Wellness” I did a month of Florastor (Saccharomyces boulardii lyo) after reading that it kills histolytica. But I should probably do another stool test now to see if these things are gone. Could any of these still be causing the problems I have?
Thanks Bill. It couldn’t hurt to try it. I’ll report back with the results.
Hi Traci,
Well, if you like the exercise and it makes you feel good then keep it up. Good for you! Usually your body will tell you if you need rest.
A reaction to only 150 mcg iodine can happen with a deficiency of selenium or copper. If the latter you should react similarly to the copper. I suppose the other possibility would be bromine symptoms. If so then the severity would go up with the iodine dose.
Definitely infections can cause health problems and weight gain. I’m not familiar with amoeba infections and what they can do. Infections do affect weight regulation in various ways, some of them do promote weight gain / obesity. It would be good to follow up on those. Probiotics and fermented vegetables may be helpful.
Iodine is helpful against infections, so it does seem worthwhile to fix any selenium deficiency and detox for bromine while working up iodine intake slowly.
Best, Paul
I didn’t read all the responses, so maybe someone already mentioned this. Dr. Guy Abraham says Mg is the other necessary item needed to work with iodine supplementation to cure both Hashimoto’s and Grave’s. It’s in the #5 article of his items on iodine.
Thanks, virginia. Magnesium is a very important mineral for many bodily processes.
Virginia,
I know that both Dr. Guy Abraham and Dr. Brownstein recommend magnesium. But this is something I really do not understand, since Mg is elevated in hypothyroidism:
http://www.ncbi.nlm.nih.gov/pubmed/18322655
http://www.ncbi.nlm.nih.gov/pubmed/15926468
http://www.ncbi.nlm.nih.gov/pubmed/9494058
My Mg levels, for example, are above top range while supplementing with 1 tablet of Now Mg Citrate 200mg (50% RDI): 2.38 mg/dl, range 1.6 ~ 2.3 mg/dl. And near top range without supplementing: 2.25 mg/dl.