Selenium, Iodine And Hashimoto’s Autoimmune Thyroid Disease


Part 1: Selenium and Thyroid More Good News (Jeffrey Dach MD, Jan 01, 2014):

A Feb 2013 article in Clinical Endocrinology declares “More Good News!!” on Selenium and the Thyroid.(1)  They go on to state,

In patients with Hashimoto’s disease and in pregnant women with anti-TPO antibodies, selenium supplementation decreases anti-thyroid antibody levels and improves the ultrasound structure of the thyroid gland.

Starting Selenium First Before Iodine Supplementation!

Many Hashimotos patients have normal iodine levels on testing.  However, for the iodine deficient patient, we would like to devise a protocol to provide iodine supplementation safely without aggravating the inflammatory thyroid disease.  This can be done with an initial period of selenium supplementation which protects the thyroid cells from oxidative damage from hydrogen peroxide used to incorporate Iodine into thyroid hormone.   After two to four weeks of selenium supplementation, it is then safe to start low dose iodine in the range of 225 mcg per day..

For Hashimoto’s patients who test low for Iodine,  our protocol starts off with selenium supplementation of 200-400 mcg per day for two to four  weeks,  after which, low dose Iodine (225 mcg per day ) is started.  A number of studies have shown that this dosage of Iodine causes no harm in Auto-Immune Thyroiditis patients.

Part 2: Hashimotos, Selenium and Iodine, Part Two (Jeffrey Dach MD):

Iodine and the Thyroid Peroxidase Enzyme Activity

Students and followers of Datis Kharrazian (“Dr. K”) and Chris Kresser say that Iodine is a stimulator for the thyroid peroxidase enzyme ( TPO).  This is contrary to published animal and human studies which examine the effect of Iodine on TPO enzyme activity, and report Iodine inhibits the activity of the TPO enzyme.   More on this later.

Iodine Worsens Hashimoto’s Thyroiditis
There is No Doubt – However Selenium Protects

The medical literature is full of studies showing Iodine supplementation worsens autoimmune thyroiditis, with measurable increases in TPO and Thyroglobulin antibody levels.(4-7)  And, many practitioners, including myself, have seen this in actual clinical practice.  In addition, I have seen cases of transient hyperthyroidism, called “Hashitoxicosis” after iodine ingestion. There is little doubt about this.  Dr. David Brownstein, author of a book on Iodine, and strong advocate of Iodine supplementation states in an interview:

“I agree that iodine can aggravate autoimmune thyroid conditions. Iodine supplementation in those that have an autoimmune thyroid problem can be akin to pouring gas over a fire.”(3)

Proponents of Iodine for Hashimoto’s

On the other hand, proponents of Iodine such as Drs. Guy E. Abraham, David Brownstein , Jorge D. Flechas  and David Derry have successfully used Iodine treatment in many patients with Hashimoto’s.  Iodine message boards, such as the Yahoo Iodine Group (with 3900 members) report many Hashimoto’s patients doing well and recovering on Iodine Supplementation.

Selenium Protects the Thyroid Gland in Hashimoto’s

The answer is the role of selenium.  Selenium deficiency is the underlying prerequisite for iodine induced thyroid damage in Hashimoto’s Thyroiditis.  Selenium supplementation is protective and prevents thyroid damage from iodine.  Iodine opponents such as Dr K and Chris Kresser as well as the studies they quote tend to ignore the role of selenium.

Part 3: Iodine and Hashimoto’s Autoimmune Thyroid Disease (Jeffrey Dach MD, Feb 7, 2015):

In Table 4, the higher Iodine intake of 556 mcg/ per day was associated with recovery in 18 patients !!!  This is just the opposite of Dr. Yoon’s hypothesis that Iodine restriction is beneficial.

My second criticism is: How on Earth can one conclude that Iodine restriction is beneficial when the Recovered patients had 556 mcg/day of Iodine intake?  This is half a milligram of Iodine daily !!  This is certainly not Iodine restriction !!

Dr Yoon wanted to predict which patients would recover normal thyroid function and which one would not, so Dr Yoon re-organized the data in Recovered and Non-Recovered patients.  As you can see from the above data, there was essentially no difference in Iodine intake nor Iodine urinary excretion when Recovered are compared to Non-Recovered patients.  Dr. Yoon even admits in the article the level of Iodine intake was not a factor in recovery of a euthyroid state,  yet he then goes on to recommend Iodine restriction for Hashimoto’s patients.  This is a recommendation which is not compatible with Dr. Yoon’s own data.

Iodine and Hashimoto’s Thyroiditis, Part I (Perfect Health Diet,

Note that the IS2 level of selenium, which protects against iodine toxicity, corresponds in a person who drinks 1-2 liters per day to a selenium dose of 200 to 400 mcg per day – which happens to be the Perfect Health Diet “plateau range” for selenium.

Selenium Can Cure Autoimmunity

Our next study, also from China, showed that excess iodine can indeed cause such an autoimmune pathology, but only if there is a deficiency in selenium


Excess iodine intake can cause an autoimmune thyroiditis that bears all the characteristics of Hashimoto’s. However, in animal studies this occurs only if selenium is deficient or in excess. Similarly, in animal studies very high iodine intake can exacerbate a pre-existing autoimmune thyroiditis, but only if selenium is deficient or in excess.

With optimal selenium status, thyroid follicles are healthy, goiter is eliminated, and autoimmune markers like Th1/Th2 ratio and CD4+/CD8+ ratio are normalized over a wide range of iodine intake. It seems that optimizing selenium intake provides powerful protection against autoimmune thyroid disease, and provides tolerance of a wide range of iodine intakes.

In the next post in this series (Iodine and Hashimoto’s Thyroiditis, Part 2, May 26, 2011), we’ll transition from animals to humans. Does epidemiological evidence suggest that these animal findings are transferable to humans?

Iodine and Hashimoto’s Thyroiditis, Part 2 (Perfect Health Diet, May 26, 2011):

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

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.

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