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Selenium Supplementation Significantly Reduces Thyroid Autoantibody Levels in Patients with Chronic Autoimmune Thyroiditis

We have seen all too many unquantified, often unsupported, claims about selenium and thyroid antibodies. Good to see at least a little step in the direction of properly assessing the importance of selenium.

Note, though, the last sentence: Whether these effects correlate with clinically relevant measures remains to be demonstrated.

We eagerly await that demonstration.

Thyroid. 2016 Dec;26(12):1681-1692. Epub 2016 Nov 2.

Selenium Supplementation Significantly Reduces Thyroid Autoantibody Levels in Patients with Chronic Autoimmune Thyroiditis: A Systematic Review and Meta-Analysis.

Wichman J1,2, Winther KH1,2, Bonnema SJ1,2, Hegedüs L1,2.

Author information

1Department of Endocrinology and Metabolism, Odense University Hospital , Odense, Denmark .

2Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark , Odense, Denmark .



Selenium supplementation may decrease circulating thyroid autoantibodies in patients with chronic autoimmune thyroiditis (AIT), but the available trials are heterogenous. This study expands and critically reappraises the knowledge on this topic.


A literature search identified 3366 records. Controlled trials in adults (≥18 years of age) with AIT, comparing selenium with or without levothyroxine (LT4), versus placebo and/or LT4, were eligible. Assessed outcomes were serum thyroid peroxidase (TPOAb) and thyroglobulin (TgAb) autoantibody levels, and immunomodulatory effects. After screening and full-text assessment, 16 controlled trials were included in the systematic review. Random-effects meta-analyses in weighted mean difference (WMD) were performed for 3, 6, and 12 months of supplementation in two different populations: one receiving LT4 therapy and one newly diagnosed and LT4-untreated. Heterogeneity was estimated using I2, and quality of evidence was assessed per outcome, using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines.


In LT4-treated populations, the selenium group had significantly lower TPOAb levels after three months (seven studies: WMD = -271 [confidence interval (CI) -366 to -175]; p < 0.0001; I2 = 45.4%), which was consistent at six months (three studies) and 12 months (one study). TgAb decreased at 12 months, but not at three or six months. In LT4-untreated populations, the selenium group showed a decrease in TPOAb levels after three months (three studies: WMD = -512 [CI -626 to -398]; p < 0.0001, I2 = 0.0%), but not after 6 or 12 months. TgAb decreased at 3 months, but not at 6 or 12 months. Quality of evidence was generally assessed as low. Study participants receiving selenium had a significantly higher risk than controls of reporting adverse effects (p = 0.036).


Selenium supplementation reduced serum TPOAb levels after 3, 6, and 12 months in an LT4-treated AIT population, and after three months in an untreated AIT population. Whether these effects correlate with clinically relevant measures remains to be demonstrated.


Hashimoto's thyroiditis; chronic autoimmune thyroiditis; clinical effect; meta-analysis; selenium supplementation; systematic review

PMID: 27702392

DOI: 10.1089/thy.2016.0256

Full paper behind very steep paywall. :-(


Links to tables/figures in original paper:

1) online.liebertpub.com/doi/s...

2) online.liebertpub.com/doi/s...

3) online.liebertpub.com/doi/s...

11 Replies

Many thanks for this. Now I know you can get an odourless version I'm thinking of trying again.

Am I missing it or do you know does it say somewhere what dose of selenium was given?

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I have just added three links to the post. Have a look at number 3) - that shows a summary of previous research. I think the ones that declared the dose used 200 micrograms.

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I seem to remember Izabella Wentz suggesting 400mcg initially. My GP here suggested Selenium 200mcg when I was diagnosed back in 2005 - but also to take a break from time to time. So when I go away I don't take them !


I'd go with 400 micrograms for a while if you know you are low in selenium. Otherwise I'd personally choose not to go above 200 micrograms. After all, we probably get at least some in our diets - even if not enough.


Many thanks. Will do.


"odourless"? I didn't know it had a smell. I eat 2 Brazil nuts per day and do not detect any characteristic smell. If I ever take Se in pill form I will look out for that.

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Tablet form can absolutely stink!

Selenium is (or was) used for electronic components like rectifiers. If one of those burned out, and that was not exactly rare, the smell would fill a stupendous volume.



I'm not squeamish and can deal w all kinds of smelly foods and pills, but I had to throw away my bottle of selenium. Not only did the tablets smell but the odour permeated the jar and contaminated the whole cupboard and it made me feel queasy every time I had to go in there.

Don't know if you've ever smelled asafoetida but the smell of selenium shares the same soul-soiling quality, as if it is not just unpleasant to your nose but also disturbing to your actual psyche.

Not sure what others would say but to me it smells like an infected wound.

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Wow, I had no idea, thanks for the info.

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I understand what you mean about asafoetida - but, in the modest amounts used in some Indian foods, I have grown to like it. Don't think I could ever like selenium smells.

Some chemists note a selenium form of phenol as the worst substance they ever had to deal with!


Yes, you can get a whiff of it walking past Govinda's in Soho. It's a sub for garlic and/or onions, which are equally pungent but unfit for Krishna.

What I meant when I compared it to selenium was the odour of asafoetida on its own. I once found myself w a huge catering-size bag of it in the boot of my car and it was an olfactory beast which could not be contained no matter how many layers of plastic bags I added.

Not for nothing it's known as 'devil's dung' and (I'm told) used in magic to drive away annoying people.


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