Good T4 to T3 converter, or not

[Megluka]

I always seem to be asking for a bit of help but I do feel I am getting there with help from this site and a wonderful fellow Hashi relative. One more question though...

How do you know if you are a good converter from T4 to T3?

What percentage of T4 converted to T3 is considered good? I have been taking selenium as I understand that selenium aids conversion but my latest tests shown in an earlier post indicate that a lower percentage has been converted...despite the selenium.

I was expecting a higher percentage.

[shaws Administrator]

It depends upon the range. Labs differ in their machines, so numbers differ.

This link should be helpful:-

thyroiduk.org.uk/tuk/testin...

FT4 and FT3 should be in the upper part of the range.

[SeasideSusie Remembering]

Megluka -

May:

TSH 0.516 (0.27-4.20)

Free thyroxine 19.86 (12-22)

Free T3 4.78 (3.10-6.80)

Conversion ratio: 19.86 : 4.78 = 4.15 : 1

July:

TSH 1.34

Free thyroxine 16.67

Free T3 3.69

Conversion ratio: 16.67 : 3.69 = 4.51 : 1

Good conversion takes place when FT4: FT3 ratio is 4:1 or less.

Were both tests done under the same conditions ie same time (early morning), overnight fast, levo left off for 24 hours?

You have to take into account your Hashi's that can cause fluctuations and you had a high CRP at the time of the July test

[Megluka in reply to SeasideSusie]

I am not sure what the high CRP means. I am off to the doc tomorrow but I don't expect he will listen to what I have got to say. Not sure how I am going to admit to taking a much higher supplement of B12 than he gave me.

[SeasideSusie Remembering in reply to Megluka]

High CRP can indicate inflammation or infection somewhere. In fact, in a previous thread Humanbean commented on this and asked

"Do you know why your CRP is so high? Were you ill at the time of the test? Do you have poorly controlled asthma, COPD, rheumatoid arthritis, or severe gut problems? Or any other chronic disease that was going through a flare up at the time of the test?"

and you didn't reply to her.

Why tell him what amount of B12 you are taking? You are within range. In fact, for us Hypos, B12 is best at the very top of range, even 900-1000. I'm surprised a GP has even given B12 supplements!

[Megluka]

I don't have any of the problems you listed but I do think my gut was not up to scratch. I was taking PPIs, now stopped, and have gone GF and been taking ACV. My last ferritin level was three times the previous reading without any iron supplements so I am presuming the any absorption problems I might have had are improving. I wonder if the possible gut problem affected the CRP level.

I told the GP about the high CRP reading and he said that in itself did not tell him anything other than inflammation or infection. I am going on holiday and when I return in August I am booked in for repeat B12, Vit D, full blood count...although I think the FBC will only show there is an infection, but not where.