Thyroid UK
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thyroid hormone conversion and transport

A couple interesting papers from the Holtorf medical group recently came to my attention. These help explain why TSH-only diagnosis often does not work, and why other health conditions that are present with thyroid disorder, have a large effect on tissue hypothyroidism. Of course you already know those things, but the long lists of references provide authority!

"Peripheral Thyroid Hormone Conversion" (2014)

This paper ranges over a large number of topics, including: explanation of the deiodinase enzymes (D1,D2,D3); why biochemistry of the pituitary is different than rest of the body, so that TSH does not predict tissue hypothyroidism; how glucocorticoids stimulate D3, resulting in more rT3; the effectiveness of T3 in treating depression; supraphysiologic T3 doses effective in treating unipolar & bipolar depression; T4->T3 conversion decreased by many non-thyroid health conditions such as obesity; empirical evidence showing iron deficiency,inflammation,toxins reduce T4->T3 conversion.

""Thyroid Hormone Transport" (2016)

This paper ranges over some of the same issues as in the previous paper, and some others not previously covered, including: explains how thyroid transport is energy-based (not diffusive) outside the pituitary; how pituitary transport is different; how important FT3/rT3 ratio is in diagnosing tissue hypothyroidism; how it is impossible to achieve normal T3 levels with T4-only therapy (except in pituitary); that a very low TSH is not an indicator of hyperthyroidism 84% of the time; why TSH level is not a good way to determine thyroid hormone dose.

These papers contain fodder that can be used against ignorant GPs and endos. However, keep in mind that it is not a good idea to present this information to a doctor in the early stages of your relationship. I would not highlight the relevant issues presented, for presentation to your doctor, unless you have become disgusted with his/her lack of expertise and are prepared to jettison him/her, if the doc is one of those who cannot tolerate challenge to their authority.

8 Replies

Thanks for posting this Eddie 83 ,just what i need to give to GP (,above comments noted ,) just been diagnosed with poor conversion this week with private blood tests ,have a lovely xmas .:))


Wow, great site and articles - thank you!


Thanks very much the more we lean the better able we become to manage our condition


Thank you for posting. Having taken my daughter from the UK to a doctor in the US after many futile years of searching for help in the UK she was finally diagnosed with a number of illnesses including several that create toxins causing inflammation. The interesting thing about all of the patients that she met at the clinic she now attends was that they were all on thyroid replacement even though in many cases they had never had a blood test that was out of range. She herself has been on T3 (purchased abroad) since 2002.

We brought the information about her diagnosis and treatment back to the UK with us and have made many attempts to share it with doctors, charities, PHE and other health professionals. Sadly none of them showed the slightest interest, most notably my daughter's GP, who prefers to tell her that she has ME/CFS and to live with that diagnosis.

There are many and various causes of thyroid dysfunction, but unfortunately in the UK too many patients are not taken seriously and remain ill for many years. This forces them to take matters into their own hands and seek out a reliable doctor abroad to assist them. Fortunately we were very lucky and found a brilliant and scientific specialist, but nobody should have to go to such lengths when the research and information is all out there and readily available.

Jane x


Curious about whether the US doc(s) identified underlying cause! Did the docs you took her to, determine that she has toxic conditions that can be resolved by removing unsafe foods from her diet, and/or fixing problems stemming from environmental pollution? Reason I ask, is that the Tom O'Bryan video on youtube about The Autoimmune Fix, implies that many of the mysterious ailments that allopathic medicine is clueless about, are due to autoimmune conditions that are tearing up the body from inside, but which the allopaths don't even test for.


Tearing up the body from the inside is a very good term. In the US she was tested for a number of things including mycotoxins, Lyme, HHV6, candida - all of which were positive. Her methylation and nagalase levels were consequently way out of range and she also has MCAS and pyroluria. She was tested for none of these in the UK, and sadly as I say nobody is interested! Thankfully though her lovely doctor in the US is working things through with her, but since she has probably had these problems for many, many years we know this will take some time. Which infection came first? We shall never know, but fortunately we have found someone who can unravel it all for her. It's very unfortunate for those who cannot see such a doctor because the allopaths of this world are all too keen to treat the symptom not the patient who may never find out what is actually causing their ill health unless they take matters into their own hands. Jane x


Curious, in case you don't mind telling: which US physician is she seeing? If you want to respond but that response is not permitted by HealthUnlocked rules (I can't keep track of them!), please message me.


With pleasure. Jane x


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