Thyroid UK
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Hi , I am sure everyone is madly busy coming up to Christmas but would appreciate advice....

I have had a recent blood test ( unlike last one I took my levo 1st thing in the morning before the test as I forgot I should have not taken it.

Results as follows:

Serum TSH 1.16 ( I am happy with that)

Serum Free T4 ( couldn't believe they tested it!) 20.2pmol ( range 10.8 - 25.5)

Serum B12 they noted as abnormal at 817ng/L ( range 190- 660)

Serum folate Reference range 3ug/L

Vit D 77nmol

There were no concerns on my renal profile as there had been before, all results seem within range.

Is there any significance in my Free T4 result ( no free T3 but could get that done privately if necessary)

Do I have excessive B12?

Any advice would be really helpful.

Happy Christmas and thanks for all your past help.I feel so much better on my increased dose of levo and would never have been able to convince my GP to allow the increase without all your great advice.....


8 Replies

Alexa5000 There is nothing amiss with your FT4 result, in fact if you don't feel optimally medicated there is room for that to increase and room for your TSH to decrease.

Nothing wrong with your B12 either, recommended is very top of range, even 900-1000. We pee out any excess B12. Are you supplementing? If so reduce to a maintenance dose.

Although in the replete range, there is room to nudge up your Vit D as the recommended level is 100-150nmol/L.

It's good to hear you're feeling so much better :)

1 like

Thanks Susie - that is really helpful.I have tried nudging up T4 a bit but feel ghastly - I seem to be hypersensitive to changes in dose.Will take your advice re Vit D - especially now it is winter

Happy Christmas!



Alex, if you feel OK on your present dose with your FT4 level where it is, there's no need to change anything. Your FT4 is close to the top quarter and that's obviously a good place for you. As long as you feel good, don't let your GP change your dose.

Happy Christmas to you too :)


Thanks - wasnt planning to.I was surprised they tested freeT4 ( GP had always refused before!) so was really wondering if that sounded OK



What time was the test? Having taken your levo that morning, it's possible that you have a false high, and the actual level is lower than that.

I'm surprised you say that you're happy with your TSH, because the TSH is irrelevant once you're on thyroid hormone replacement, unless it goes high. :)


Test was at 12oc -( last TSH was .82. - 3 months ago and the test was 1st thing before levo) I guess what I am saying is that I feel well - I had been trying to get TSH down to around 1 when I increased my dose a year ago or so and have done that..

It was the B12 I wasnt sure about.I havent been taking it regularly - rather ad hoc to be honest.. also does teh free T4 sound right?

Happy Christmas! ( and thankyou)


Well, you don't know what your T4 actually is, because you took your levo that morning. And, had you had your test at 8 am, your TSH would have been higher. It's all relative. But, even if it were that level without taking the levo, it would be ok. It's not over-range, and it isn't even the active hormone.

But, even so, they don't even test the most important number. The active hormone, T3. Just because your FT4 is good and your TSH is low, doesn't mean you're converting that T4 to T3. It would be a good idea if you could get the FT4 and FT3 tested at the same time, so that you can see if you're converting well. :)


Even though you took your medication, I would say your T4 was in the upper range, but good. The GP's are cunning when it comes to the T3 test, mine conveniently forgets (ha ha) but I always make sure that I remind him/her to put it on the list for testing.

Can't comment on B12 as my levels are deficient and I not really understand it.

I also never understand the TSH levels either as mine have always been around the 0.09 as my partial gland has never worked so always been on medication.

Are they retesting you in a few weeks or was that your annual check up? It would be interesting to see what your T4 levels are without the medication prior to testing.

Take care :)


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