Hi, I had the Regenerus test for DIO2 gene which came back positive for the Heterozygous variant genotype TA. I took this test as I suspected I do not convert T4 well and my blood results show this. Unfortunately the endo I saw in Cambridge tells me they no longer take these test results to mean you would need T3. Here is an exert from her letter
The letter from Dr suggested that you had had your deiodinase enzyme activity checked somewhere which showed you to be heterozygous for one enzyme (although not which one). This is not a test used in routine thyroid management, as there are a number of deiodinase enzymes and it is not clear which are biologically important. At the moment we don't believe that there is firm evidence to say that heterozygotes benefit from combination treatment with thyroxine and liothyronine (T3). Deiodinase function will also have been affected by the fact that your thyroid function tests have been outside the normal range for a long time.
Has anyone else had this message from their endos?
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janey_k
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what a great pity ....there are endocrinologists who do recognise Dio2 as need for T3
Email Dionne at Thyroid UK for list of recommend thyroid specialist endocrinologists who will prescribe T3....many will be private ..certainly initially
For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also EXTREMELY important to test vitamin D, folate, ferritin and B12
Low vitamin levels are extremely common, especially if you have autoimmune thyroid disease (Hashimoto's) diagnosed by raised Thyroid antibodies
You may need to get full Thyroid testing privately as NHS refuses to test TG antibodies if TPO antibodies are negative
Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .
Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).
This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)
(If/when you are eventually also on T3, make sure to take last third or half of daily dose 8-12 hours prior to test, even if this means adjusting time or splitting of dose day before test )
Is this how you do your tests?
Private tests are available as NHS currently rarely tests Ft3 or thyroid antibodies or all relevant vitamins
Thanks for your reply SlowDragon. The endo is an NHS one who was recommended by someone as she is T3 friendly. Prior to the lockdown she agreed I could have a trial of T3 but it seems to me she has forgotten this. Below is another exert from her letter:
I agree with REDACTED conclusion last year that there is no indication to prescribe liothyronine alongside thyroxine. As you know, guidelines for thyroid hormone replacement do not support the use of T3 / T4 combination therapy and we are unable to prescribe liothyronine at present. Furthermore, we would not do so until your thyroid function tests had been normal on thyroxine alone for a suitable length of time to allow symptom review. If these guidelines change in the light of new evidence, and once you have had normal thyroid function tests on thyroxine for at least 3 - 6 months, then we might be able to re-visit the issue at some stage in the future.
No Hashimoto’s. Thyroid removed because of thyca. After thyroid was removed in 2005 I was on a high dose of 200mcg and was kept on this dose for a long time. My TSH has always been suppressed.
I currently take 125mcg.
My last results:
TSH <0.03 (0.35-5.50)
FT4 22.2 (10.5-21.0)
FT3 4.8 (3.5-6.5)
Tissue transglutaminase IgA antibody0.4 u/ml (0.0-6.9 u/ml)
All done by the NHS when I went to my appointment. Unfortunately I took my dose at 3am the morning of my blood draw.
When my dose was reduced to 100mcg levo I felt so unwell, all of my current symptoms were magnified. I begged my gp to put my script back up to 125 which thankfully he did.
OK, it looked like vit D was 375 but I see you had just omitted the gap between D3 and the result numbers. And you've clarified it's nmol units so all OK although some would say on the lowish side.
Suggest you try increasing levothyroxine as first option.
If you felt well at higher dose previously, that’s easiest option to try
Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,
"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.
In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.
Most patients will feel well in that circumstance.
But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.
This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."
You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor please email Dionne at
Thanks Slowdragon. Vit D3 result was 75.1 and Vit D2 was <5.
I doubt I could persuade the gp or endo to up my levo dose as they're so fixated on getting my TSH up. When my dose was dropped to 100mcg my TSH rose to 0.08. I wonder how far they'll let me drown to get to the magic number of theirs!
Thank you for the Dr Toft info and all your input so far! Much appreciated
I'm sorry you seem to be hitting your head against a brick wall.
I took to self medicating some 18 months ago after I was refused a trial of T3 by my local hospital. I am with Graves Disease, post RAI thyroid ablation in 2005 and became seriously unwell some 6 years ago being dosed and monitored on just a TSH blood test.
I found this site, a few years ago and started reading up and ' jumped the NHS ship ' after being denied T3 because of my suppressed TSH, as it seems like a game of cat and mouse, whilst our health appears to have been taken off the table and doesn't matter anyway.
A fully functioning working thyroid would be supporting you on a daily basis with approximately 100 T4 + 10 T3 and I read T3 is about 4 times more powerful than T4 and that most people need about 50 T3 daily just to function.
I'm so sorry you need hasn't been acknowledged and would hazard a guess that if you went private you wouldn't have a problem obtaining T3 and T4 and with a bit of luck find a doctor who has some understanding and empathy in treating you with the options that are widely available in other countries.
There is a list of ' sympathetic endos ' held at Thyroid uk - so it might be an idea to check this out, and if you are well enough to travel, might be an option.
Thanks for your reply Pennyannie. As if it's not exhausting enough living with this condition we have to spend so much energy being our own advocates! It's great having a platform like this to get fellow sufferers take on things and the support.
I realise I could go private but I'm trying to exhaust all other avenues first.
Well, I would in your position - you are ' in range ' so may not get a prescription, even if you can ' stomach ' them :
I maintain my ferritin with Asda frozen chicken livers - they are very clean and once defrosted can be flash fried, and I then whizz them down with a dollop of mayo, and pop them in the fridge in a jam jar and use one little tub a week, taking a spoonful each morning just to keep me topped up.
Being somewhere in the NHS range isn't necessarily adequate for people with thyroid health issues, so again, suggest you take a look SeasideSusie replies to posts as she is ' our very own, very special, vitamin and minerals queen.
You really need FULL iron panel test before supplementing iron. You might not have low iron, only low ferritin
Alternatively Eating iron rich foods like liver or liver pate once a week plus other red meat, pumpkin seeds and dark chocolate, plus daily orange juice or other vitamin C rich drink can help improve iron absorption
Just to say that I too have a very healthy balanced diet but we are hypothyroid and our bodies may not be metabolising well enough to utilise all the nutrients we need from our food as well as they might.
As previously mentioned I'm now self medicating with NDT and very much improved. I still have to maintain my ferritin, folate, B12 and vitamin D at optimal levels, and it does require supplementation, and a yearly blood test to tick box and adjust where necessary.
Understood, but as per your advice I already consume regularly what you have advised. Do you also advise that I increase my supplements? As per my earlier reply I use the Better you D2 spray and I have just started to supplement with selenium and magnesium. Thanks
I have not had the DIO2 test so I will just pass on what was said to me by my endo. He said not everyone who has the gene mutation is hypothyroid so it is not really definitive. I have no idea if that makes sense. I can tell you this. He also has a preoccupation with TSH. Honestly. I feel your frustration.
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