Latest results and some advice please.

[Jphill49]

Hello

I posted on here last year for advice on my blood test results and had some very helpful replies. My latest test results from 12/04/22 at 7am.

Ft4- 14.6 pmol/L (9.1- 17.6)

FT3- 3.9 pmol/L (2.4- 6.0)

TSH- 0.04 mu/L (0.35- 4.9)

Thyroid peroxidase antibodies 62 iu/m/L (0.0- 6.0)

Ferritin 98 ug/L (5.0- 204.0)

Folate 6.3 ug/L (3.1- 20.0)

Vitamin B12 404 ng/L (187- 883.0)

Vitamin D 98 nmol/L (50.0- 200.0)

The gp is still talking about lowering the dosage due to ‘abnormal results’. I’m still taking alternate 125mcg and 100mcg. But now says it’s up to me.

The only supplements I’ve been taking are vitamin D3 2000, magnesium glycinate, and vitamin K2 MK7. I stopped them 2 weeks before the test. Not sure if the magnesium is the right one or if the strength is right for me.

I’m on a gluten and dairy free diet since last year and have lost 37lb. My fatigue is worse than it was so should I now start taking vitamin b12, folate and ferritin supplements now? Thanks in advance.a

[McPammy]

Your TSH is suppressed. I’m guessing you had your latest blood draw for your tests without taking your daily medications. If that’s so, once you take your medication your T4 could be going over range causing your TSH to be suppressed. My experience of suppressed TSH is low energy levels. Being over medicated can feel like being under medicated. If you could do another test 2-4 hours after ingesting your meds you’ll see a different result and this could identify why you’re feeling low in energy. Or reduce your T4 medications slightly and see if you improve. It could take a good week to feel any improvement

[Jphill49 in reply to McPammy]

Thanks for your reply. That’s interesting, my tsh has been suppressed for years and always feel tired all that time. A long time ago the gp told me I had chronic fatigue syndrome which went hand in hand with underactive thyroid. So probably more likely over medicating.

[McPammy in reply to Jphill49]

We all try to get out TSH around 1.00. This is generally where a healthy persons TSH would be. I do know when I’m over medicated and my TSH has been suppressed I feel exhausted. As soon as it comes back in range I’d be good again. Try reducing your medication slightly and see how you feel. Then get another test.

[tattybogle]

being pragmatic .. one of the easiest things to try out for yourself, is to try a very slightly lower dose for a couple of months to see how it feels. Slight overmedication can feel similar to slight undermedication, and the only way to really know if you'd feel better on slightly less , is to try it for long enough to see.

I didn't feel overmedicated on 125mcg , in fact i used to be on 150mcg for many years , so might have thought i needed more not less. but my fT4 was very over range so i agreed.

In my experience of lowering from 125 to 112.5mcg , the first 4/5 weeks did not feel like an improvement , in fact if i'd had to make my mind up at that point , i would have said it's too little ..... i became a bit constipated for about a week or two but that improved again , i felt more tired, and a bit 'flat' for a few weeks , but again this improved slowly . I'm very glad i stayed on the lower dose for longer to see how it went , because by about 3 months i realised i was sleeping much better than i had for years, and all sorts of recurrent muscle pains that i never thought had anything to do with my levo dose had gone away. and i feel like i have a more consistent sustainable level of energy.

the GP however still wasn't happy with my over range fT4 level (which had inexplicably gone up further ) and insisted if i didn't reduce further to 100mcg i would die ( i kid you not!)... so eventually i did try 100mcg ... this was definitely too little ... constipation happened again , but this time instead of getting better after a week or two, it got worse ... and so did everything else, my digestive system more or less went to sleep .. it was as if food just sat in my stomach like stone.. and i was so foggy brained i was honestly struggling to crossing the road. ... so after 6 weeks of this i went back up to 112.5mcg . and everything improved again over the next few weeks and has stayed ok for a couple of years now.

At the very least ,even if it doesn't improve things, you've ruled it out .. and you can report this experiment and any worsening of symptoms to the next GP who insists you need to lower your dose ... which will speed up process of searching for alternatives like adding a bit of T3 .

Your fT4 has been ? over range on 112.5mcg sometime last year ,

then FT4 16.5 (9.0- 19.1). (74%)

now FT4- 14.6 (9.1- 17.6) (59%) .... different range ..is it same NHS lab?

So fT4 seems to be falling anyway ,which makes it rather less likely that overmedication is the problem here . but fT4 level is influenced by when you took the last dose....

Were all these tests done with similar time gap from last dose levo ?

[Jphill49 in reply to tattybogle]

Thanks for your reply. I saw that the reference range was different but I’m not sure if the same lab was used as before, I had a look online for the previous test info but it was no longer there. I will find out next week out of interest. I took the last dose of thyroxine longer than 24 hours before the blood draw so that would have affected the result? Previous tests were usually at least 24 hours before hand.

[tattybogle in reply to Jphill49]

yes ,, the fT4 result is directly affected by time of last dose. The TSH result is not affected much if at all by time of last dose (it takes days/weeks to respond to lower / higher dose) ,, it is however affected by the time of day the test is done.

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fT4 will be 'falsely' high from about 2-6 ish hours from last dose ( when it all gets absorbed into the blood from the gut) it then falls closer to the average level for that dose by about 12 hours after taking the tablet ,, and by 24 hours it will be at the average base level for that dose. So '24 hours' is recommended for testing consistently (but anywhere from 12 -24 hours is going to be fairly representative of fT4 level for that dose )

The longer you leave after 24 hours the lower it will go. so eg .36 or 48 hrs will not be a fair representation of fT4 level for that dose .

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TSH has a circadian rhythm... so it is highest every day in the middle of the night / very early morning .. falling to it's lowest every day at about 1-2 pm .. than slowly rising again over the early evening.

So TSH at 8/9 am will give higher result than 1-2pm....... for this reason 8/9 am is recommended for consistency.. (and gives highest TSH if looking for a diagnosis, or to avoid inappropriate dose reduction) but you can test TSH at other times of day as long as you take this into consideration when interpreting the result.

The important thing is to take you tests under consistent conditions so you can properly compare the results with the previous ones.

[Jphill49 in reply to tattybogle]

That’s useful to know, thank you. I didn’t realise it would make such a difference to the fT4 result.