T4 to T3 conversion ratio: Hey! I wanted to work... - Thyroid UK

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T4 to T3 conversion ratio

Bexg profile image
Bexg
18 Replies

Hey! I wanted to work out my ratio have complete brain fog on how to do it!

Can someone post the calculation or link to a Polish? Site

FT4 currently 22

FT3 currently 3.2

Also DI02 testing... Experiences of test and how receptive GP/endo is with result.

Many thanks

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Bexg profile image
Bexg
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18 Replies
greygoose profile image
greygoose

I think we need the ranges to work out the ratio. :)

Just out of curiosity, why do you want a link to a Polish site? Or is that a typo? :D

Link is: chorobytarczycy.eu/kalkulator

greygoose profile image
greygoose in reply toAngel_of_the_North

How does that work? I tried, but I don't speak Polish, so obviously got it wrong! :)

Marz profile image
Marz in reply togreygoose

You type in your FT4 result - followed by the bottom figure of the range - followed by the top ! Ditto for FT3 - then Press the blue button below - and hey presto the percentages appear !

greygoose profile image
greygoose in reply toMarz

Oh brilliant! lol First time I've seen that. :)

Marz profile image
Marz in reply togreygoose

I have posted it before - possibly years ago !

greygoose profile image
greygoose in reply toMarz

Oh, well, you know what my memory is like! lol Thanks, anyway. :)

Marz profile image
Marz in reply togreygoose

healthunlocked.com/thyroidu...

You may find the above discussion interesting :-)

greygoose profile image
greygoose in reply toMarz

Yes, very interesting! lol

Marz profile image
Marz in reply togreygoose

healthunlocked.com/thyroidu...

.... and another !!

SeasideSusie profile image
SeasideSusieRemembering

Bexg

You just divide FT4 by FT3 to get the ratio

22 divided by 3.2 = 6.875 : 1

Bexg profile image
Bexg in reply toSeasideSusie

Oh yes!! 🤣🤣🤣 I remember now.

kiefer profile image
kiefer in reply toSeasideSusie

What concentrations for FT4 and FT3 are you using for these calculations?

This only works if blood levels are re-calculated to comply with those fixed concentrations. Otherwise, the mathematical result won't fit into the same ratios that you use to determine a normal range of conversion.

My FT4 was 0.7 ng/mL

My FT3 was 3.2 pg/mL

0.7 divided by 3.2 = 0.21875 : 1

SeasideSusie profile image
SeasideSusieRemembering in reply tokiefer

Kiefer

You are in the US with different ranges and units than those we have in the UK so I can't, and don't, suggest that method for your results.

In the UK for both FT4 and FT3 it's pmol/L.

See if the calculator that Angelofthenorth linked to is any help for your results

chorobytarczycy.eu/kalkulator

kiefer profile image
kiefer in reply toSeasideSusie

I already checked the link. It was on how to determine the percentage in normal range.

Perhaps you could direct me to where you obtained the T4 to T3 conversion ratio concept? I've done a lot of reading but it's always possible to completely miss important stuff.

The first time I "heard" about calculating a T4 to T3 conversion ratio was on this forum and it makes perfect sense to determine if T4 is being utilized effectively before just dogmatically raising the dose.

SeasideSusie profile image
SeasideSusieRemembering in reply tokiefer

Yes I understand that the calculator gives the percentage, it's still useful as it shows how far through a range the result is and you can see if they're in balance or whether there is a problem with conversion.

I don't know how to change the unit of measurement of FT4 to that of FT3 for your country's ranges, it's not something that I need to do, as I say I only give the information about dividing FT4 by FT3 when it's UK results. Have you tried Googling for a method?

The information about dividing FT4 by FT3 when units of measurement are the same was originally posted by member diogenes - Dr John Midgeley - who is an advisor to Thyroid UK

thyroiduk.org.uk/tuk/About_...

kiefer profile image
kiefer in reply toSeasideSusie

Okay, thanks for your feedback.

Bexg profile image
Bexg

Wow!!! Thanks to all that have replied. It's certainly a hot topic especially with T3 prescription.

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