Latest thyroid test results

[Gecko22]

Hi everyone,

After being underdosed on 25mcg of Levothyroxine for almost a decade, my new GP increased my dose to 50mcg around 6 months ago. The increase was done slowly over 6 weeks, as advised by people in this group. I had some blood tests done two days ago and today I got a message from the GP saying that my dose needs to be adjusted. Test results are below:

Serum TSH level < 0.03 mU/L [0.35 - 5.5]; Below low reference limit

Serum free T4 level 26.4 pmol/L [10.5 - 21.0]; Above high reference limit

Serum ferritin level 56.4 ug/L [10.0 - 291.0]

Serum total 25-hydroxy vitamin D level 151.2 nmol/l

I’d actually gone for other tests and wasn’t expecting thyroid bloods to be done and had taken my Levo a couple of hours earlier but the nurse added on the thyroid test when I got there. The penny didn’t drop until I got home. I was feeling pretty awful on 25mcg and I did feel a small improvement when my dose went up but I'm now feeling equally awful and getting a lot of palpitations. I've had Long Covid for over 3 years, have ME and was recently diagnosed with hypotension. I also started a trial of HRT around 5 months ago on the advice of my ME doc. Any thoughts/guidance on what might be going on and where to go next with this would be very gratefully received!

These are my previous test results (done at a private lab):

Triiodothyronine (FT3) 4.1 3.1 - 6.8 pmol/L

Free thyroxine (FT4) 16.0 12.00 - 22.0 pmol/L

Thyroid stimulating hormone (TSH) 2.97 0.27 - 4.2 mIU/L

Thyroglobulin antibodies (TgAB) 31.5. 0.0 - 115.0 kIU/L

Thyroid peroxidase antibodies (TPOab) 9.0 0.0 - 34.0 kIU/L

Thyroxine (T4) 104.0 59.0 - 154.0 nmol/L

[Jaydee1507 Administrator]

I think many of us have been caught by a surprise thyroid blood test and I now plan my thyroid meds accordingly before almost any blood test just in case they slip one in when it wasnt expected!

What dose were the private tests done at?

Tell your GP you were taking a supplement containing biotin known to interfere with the test results and also you had recently taken your Levo. Ask for a restest and make sure its done at 9am or ealrier with Levo 24hrs before.

I see you are now on B12 injections which is great so long as you are getting them often enough.

Ferritin should be around 90 - 100 for best use of thyroid hormone. Suggest increasing iron rich foods in diet and eating them often. Chicken livers, pate, red meat etc

Link with ideas for dietary iron:

dailyiron.net/https://three...

Has folate been tested?

Vit D is good, you could drop the supplement slightly.

[Gecko22 in reply to Jaydee1507]

Thanks Jaydee, I always do the same but got caught out this time! I had a separate appt booked for a cardiovascular and thyroid review next week but the nursed decided to combine them and I didn't think quick enough.

The private tests were done when I was still on 25mcg and I forgot that the GP did follow up tests in January after several months on 50mcg. These are Jan results:

Serum TSH level 1.03 mU/L [0.35 - 5.5]

Serum free T4 level 17.2 pmol/L [10.5 - 21.0]

I'm still doing weekly B12 injections and taking iron and vitamin D and my ferritin has now crept up to 56.4 ug/L and vit D is 151.2 nmol/l, the highest they've ever been. Folate wasn't done this time round. I no longer eat meat and get my iron from plant sources. My ferritin was at its lowest ever at 4 ug/L when I was still a meat eater and I seem to have done better with plants. I'll speak to the GP next week and ask for a retest. The palpitations have been a bit worrying though, and I've lost a good few kg since upping my levo dose, although I did put on quite a few on the lower dose. Swings and roundabouts!

[Jaydee1507 Administrator in reply to Gecko22]

Its strange that your TSH is so low on this latest test. What time of day was it?

Free T4 (fT4) 17.2 pmol/L (10.5 - 21) 63.8%

So your January test on 50mcg still shows room for a small increase. Get GP to retest and be sure to use the recommended protocol.

So ferritin is on the up which is great.

be sure to test folate as is also needed for use of B12.

[Gecko22 in reply to Jaydee1507]

Both the latest and January bloods were taken at 9am and in Jan I made sure not to take levo for 24 hrs beforehand. I'll make sure to get folate done again this time.

[greygoose]

Taking your levo a couple of hours before the blood draw would account for the high FT4. But it wouldn't have any effect on the TSH. That responds to the time of day. So, what time of day was the blood draw?

[Gecko22 in reply to greygoose]

The blood draw was at 9am

[greygoose in reply to Gecko22]

OK, so whatever your FT4 actually is, your TSH is suppressed. And that's probably all the doctors looks at, anyway.