T4 to T3 conversion: Hi everyone, I’m in a bit... - Thyroid UK

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T4 to T3 conversion

rubyred profile image
22 Replies

Hi everyone,

I’m in a bit of a wrangle. I’m on T3 only. I’m a graves and have had RAI about 10 years ago.

I was very unwell on thyroxine so eventually went on to T3.

I have some issues with my heart. The endocrine has told GP she thinks I should be T4 only. I’ve said no.

Please can someone advise. I think there’s a blood test to check if I am able to convert. How would I go about this.

Thank you x

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rubyred profile image
rubyred
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SeasideSusie profile image
SeasideSusieRemembering

rubyred

I think there’s a blood test to check if I am able to convert. How would I go about this.

You have to be on Levo only to know how well you convert. If TSH is nice and low (1 or below) you look at the FT4 and FT3 and that tells you. If FT4 is high and FT3 is low you don't convert well, if they are reasonably well balanced or FT3 higher than FT4 then you convert well enough.

It's impossible to know or test for if only taking T3.

SlowDragon profile image
SlowDragonAdministrator

You could consider trying adding some levothyroxine in

Starting with 25mcg levothyroxine

Many people after RAI do need small dose of T3 prescribed alongside levothyroxine

Less common to be on only T3

For good conversion of Ft4 to ft3 it’s important to have good vitamin D, folate, ferritin and B12

When were vitamins last tested

What vitamin supplements are you currently taking

How much T3 are you currently taking?

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)

If/when also on T3, make sure to take last third or quarter of daily dose 8-12 hours prior to test, even if this means adjusting time or splitting of dose day before test

rubyred profile image
rubyred in reply to SlowDragon

Hi, I’m on 50 mcg T3. Ferritin is fine Vid D I think interferes with one of the heart meds I’m on. Get out in the sun whenever it shines.

I was so unwell on thyroxine. My husband had to do the shopping, cleaning washing everything. I just about managed to hold onto my office job. If I went the cinema or anything after work I had to take the next morning off.

Before I got T3 I was on the verge of having to go part time of just finish work.

I can’t go back to that. X 🥲

SlowDragon profile image
SlowDragonAdministrator in reply to rubyred

I wasn’t suggesting you should go on just levothyroxine

I was extremely unwell and immobile on inadequate dose levothyroxine and without small doses of T3 prescribed alongside levothyroxine

But you might consider trying an addition of levothyroxine....any change would need to be done extremely slowly

Many of us on levothyroxine plus T3 have Dio2 gene variation

I am heterozygous Dio2. It’s a relatively common genetic variation. It doesn’t mean we can’t convert but it does mean heart and brain need constant access to steady dose of T3

Adding small dose T3 was revelation - prescribed on NHS

Dio2 gene test

thyroiduk.org/deiodinase-2-...

All four vitamins need to be optimal for levothyroxine or T3 to work well

FancyPants54 profile image
FancyPants54

Well there is the Dio2 Gene test. If you have inherited this issue from 1 or both parents it affects your ability to convert T4 to T3. But my GP wouldn't even read the results because he didn't understand it. My private endo understands though and so I get T3 from him which I have to pay for. I have atrial fibrillation. The cardiologists don't have a clue it seems that AF is as likely with low FT3 as with high. And they miss the point that the heart and brain are 2 of the biggest users of T3. EPs understand this better I have been told but I've not seen one of those yet.

Only you know how bad you felt on T4. You will have to fight for this I'm afraid. Perhaps ask for a referral to an EP.

msmono profile image
msmono in reply to FancyPants54

What is an EP please?

rubyred profile image
rubyred in reply to msmono

EP is short for Electrophysiology. I think and I’m new to all this they are cardiologist who have done extra trading on the rhythm of the heart and they do internal cardioversion (shocking the heart) and ablation (burning the damaged bit) that’s very crude but the best I can describe with my limited knowledge xx

rubyred profile image
rubyred in reply to FancyPants54

Hi fancypants54

I was diagnosed in November with Af plus dilated cardiomyopathy and heart failure. I’m under an interventional cardiologist who is linked to an EP. The EP has just done an internal cardioversion but I have reverted back to AF. I am about to start Amiodarone. Then will have another internal cardioversion. If my ejection fraction improves after that they will do an ablation. If I have to go back to Levo I won’t be able to carry on working. I just don’t know what way to turn. 😕

rubyred profile image
rubyred in reply to FancyPants54

Fancypants54

Please can I ask the Dio2 test does this show if my body isn’t converting T3 to T4. Do you know how I would get one. I’m assuming I need to pay for it. X

FancyPants54 profile image
FancyPants54 in reply to rubyred

The test is private and is done through Regenerous Labs. regeneruslabs.com/products/...

It doesn't "show" your body isn't converting. But rather it shows if your body stands a good chance of converting or not. My GP wouldn't even read the test results because he said he didn't understand it. But my private endocrinologist understood what it meant straight away and said "in which case you will need to take some T3".

The test will tell you if you have inherited a genetic problem with production of a tiny enzyme responsible for removing the iodine molecule from T4 to convert it into T3. If you have inherited this genetic fault from one parent as I have, then your conversion will be compromised regardless of how good your cofactor vitamin and mineral levels are. If you have inherited it from both parents then you are really going to struggle to do anything with Levothyroxine and it will probably make you feel ill.

For me the test was an essential next step. But I understand hypothyroidism very well now and therefore I knew what the result meant and I was prepared to pay privately for an endocrinologist who understood it too. I would have got nowhere other than even more frustrated if I had relied on my GP to understand what it meant. So you have to weigh all those things up.

rubyred profile image
rubyred in reply to FancyPants54

FancyPants54,

Thank you that’s really helpful. I’ve been onto the site and can see how to order. It’s also asking if I want someone to check the results but I’m not sure if this is worth it as says it would be a nutritionist.

Did yours have to go via your GP surgery as reading the site it seems to suggest it can’t be sent directly to me an needs to go to a health care provider. Is this what you needed to do.

Can I also just ask. Are you able to read and understand the results ? Xx

FancyPants54 profile image
FancyPants54 in reply to rubyred

Hi. You need the nutritionist. It’s no use them sending the test results to your GP, they won’t know what to do with them. And because it’s a genetic test there are rules they have to comply with, one is that the results are sent to a professional who understands how to interpret them and can explain it to you. I think it’s a legal requirement. Even if it isn’t, they are rather involved and genetically technical. You need the interpretation. Mine was very nice and explained things very well. After the conversation she sent me my results.

rubyred profile image
rubyred in reply to FancyPants54

Thank you so much FancyPants54 for your support and guidance. I’ve sent my order this evening and included the interpretation of the results.

Xx

FancyPants54 profile image
FancyPants54 in reply to rubyred

Excellent! It helps you, even if your GP is clueless, to know if it's a reason that you feel so unwell. diogenes has posted the start of something interesting today about Dio2 and Dio3 and how they work with T3. Go and have a look and then keep your eye out for more on that as it comes in.

rubyred profile image
rubyred in reply to FancyPants54

Thank you. I will have a read. Yes your right I need to know if the reason I’m so unwell with thyroxine is due to a defective Gene. At least I will have some ammunition with my current wrangle with the endo who had said she will support cardiologist.

During a conversation I had with cardiologists receptionist I said I was at stalemate with endo she admitted the cardiologist was wishing to keep well out of it between me and the endo.

Don’t think this tale has ended yet. Xx

helvella profile image
helvellaAdministratorThyroid UK in reply to rubyred

Maybe we shouldn't say you have a defective gene? Rather the treatment being provided is defective - for you.

rubyred profile image
rubyred in reply to helvella

Helvella yes your quite right it’s defo better to describe the treatment as defective rather than myself xx

FancyPants54 profile image
FancyPants54 in reply to rubyred

If the cardiologist won't help you, ask for a referral to and electrophysiologist. They should understand the T3 equation better.

humanbean profile image
humanbean

Heart issues can be caused by low iron and ferritin (iron stores). I'm sure other nutrients have effects on the heart as well. Have you had your nutrients tested in recent months? I'm talking about vitamin B12, folate, vitamin D, ferritin and iron.

In my own case very low iron and ferritin caused arrhythmia and tachycardia. Now that my iron and ferritin are much better than they used to be the arrhythmia has virtually disappeared. But sadly, having been triggered, the tachycardia is still an issue, although nothing like as bad as it was.

jgelliss profile image
jgelliss in reply to humanbean

I'm so sorry humanbean that you still have some arrhythmia issues even after supplementing with Iron. Are you on Levo sole ? I had arrhythmia too for many years . Iron helped me very much and a small dose of T3. And splitting my T4 made a huge difference.

SlowDragon profile image
SlowDragonAdministrator

Absolutely essential to test vitamin D, folate, ferritin and B12 annually

Frequently necessary to supplement to maintain optimal vitamin levels

tattybogle profile image
tattybogle

Just in case it's got anything you might find useful in it regarding your heart issues i thought i'd link you to this old post that i'd forgotten about until recently.healthunlocked.com/thyroidu....

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