New Bloods - Very Confused

[whatevs]

I've been on 35mcg T3 and 89mcg T4 since Autumn 2019 and these were my results back in October:

TSH 0.392 mIU/L (Range: 0.27 - 4.2)

Free T3 6.3 pmol/L (Range: 3.1 - 6.8)

Free Thyroxine 10.300 pmol/L (Range: 12 - 22)

But here are my latest results on the same doses:

TSH 0.162 mIU/L (Range: 0.27 - 4.2)

Free T3 4.9 pmol/L (Range: 3.1 - 6.8)

Free Thyroxine 8.820 pmol/L (Range: 12 - 22)

So TSH is now suppressed but FT3 has dropped (?!) I can't reconcile that - so wondered if any of the lovely people on here can advise what might have happened ? I don't see the point in lowering my T3 with the FT3 value having reduced.

Also here are my latest vitamin results:

Folate - 5.28 ug/L Range >3.8

Serum Vitamin B12 - >150 pmol/L Range: > 37.5)

Active Vitamin D 89.2 nmol/L

[SlowDragon Administrator]

How do you take your T3, as single dose or as split dose 2 or 3 times a day?

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .

Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

If/when also on T3, make sure to take last third or half of daily dose 8-12 hours prior to test, even if this means adjusting time or splitting of dose day before test

Is this how you do your tests?

On almost any dose of T3 TSH will become suppressed...even on inadequate dose

Folate is very low

What vitamin supplements are you currently taking?

No ferritin result?

Suggest you get levothyroxine dose increased to 100mcg per day and retest in 6-8 weeks

[whatevs in reply to SlowDragon]

Thanks Slowdragon

Yes I do my tests the same way , no levo the night before and no T3 the morning of the test.

I take it 3 times a day , 12.5, 12.5 and 10 before bed.

Ferritin was 298 (range 30-400)

Many thanks.

[SlowDragon Administrator in reply to whatevs]

So was last levothyroxine dose 24 hours before test or 36 hours before test?

If you normally take levothyroxine at bedtime/in night ...adjust timings as follows prior to blood test

If testing Monday morning, .....delay Saturday evening dose levothyroxine until Sunday morning. Delay Sunday evening dose levothyroxine until after blood test on Monday morning. Take Monday evening dose levothyroxine as per normal

[whatevs in reply to SlowDragon]

Hi Slowdragon,

I don't take any levo the night before the test - so it would have 36 hours before the blood test.

I don't know if there was a problem with my test, but I have no idea why my TSH would get lower and yet my FT3 lowered too. It just doesn't make any sense.

[SlowDragon Administrator in reply to whatevs]

TSH almost ALWAYS becomes suppressed taking T3

On levothyroxine, but especially on T3 or NDT .....TSH is irrelevant...most important results are Ft3 followed by Ft4

Your Ft4 result is a false low with 36 hour gap

But Ft4 is very low

You probably need increase in levothyroxine

Retesting in 6-8 weeks

Also improve low folate

In future....

If you normally take levothyroxine at bedtime/in night ...adjust timings as follows prior to blood test

If testing Monday morning, delay Saturday evening dose levothyroxine until Sunday morning. Delay Sunday evening dose levothyroxine until after blood test on Monday morning. Take Monday evening dose levothyroxine as per normal

Suggest you read about this

thyroidpatients.ca/2019/09/...

[whatevs in reply to SlowDragon]

Thanks SlowDragon

Given the half life of T4 I'm surprised the 36 hour gap could impact on FT4 levels so much. Part of me is reluctant to change my test prep because I've done it this way for years.

I'm also still no closer to understanding how a fall in TSH can also result in a fall in FT3 - it goes against everything I've learnt about our condition over the years. I appreciate we shouldn't pay much attention to TSH when we introduce Liothyronine but a lower TSH should usually correlate with a higher FT3 right ?

I'll try increasing the Levo to 100mcg for 4-6 weeks as per your advice and definitely start taking my Folinic Acid daily again, I've obviously slipped.

[SlowDragon Administrator in reply to whatevs]

Looking at previous posts you have Hashimoto’s

Are you on strictly gluten free diet or ever tried it?

Do you supplement B12?

Low Folate

Many Hashimoto’s patients have MTHFR gene variation and can have trouble processing folic acid.

thyroidpharmacist.com/artic...

Supplementing a good quality daily vitamin B complex, one with folate in not folic acid may be beneficial.

chriskresser.com/folate-vs-...

B vitamins best taken after breakfast

Igennus Super B is good quality and cheap vitamin B complex. Contains folate. Full dose is two tablets per day. Many/most people may only need one tablet per day. Certainly only start on one per day (or even half tablet per day for first couple of weeks)

Or Thorne Basic B or jarrow B-right are other options that contain folate, but both are large capsules

If you are taking vitamin B complex, or any supplements containing biotin, remember to stop these 7 days before any blood tests, as biotin can falsely affect test results

endo.confex.com/endo/2016en...

endocrinenews.endocrine.org...

[whatevs in reply to SlowDragon]

Hi SlowDragon,

I think you've asked me about gluten free in the past and it's not something I wish to try as I'd rather optimise my thyroid first because I love gluten

I inject B12 on a monthly basis.

I have had problems historically with low folate levels and have been prescribed 5mg of Folic Acid by a GP in the past but I take Folinic Acid now after speaking to a researcher who has expertise here. Unfortunately I've been inconsistent with it, so will now start taking daily.

Also - thanks very much for posting that link to thyroidpatients.ca/2019/09/...

Very interesting reading - they mention not being afraid of low FT4 in the presence of higher FT3 but they don't go into what the 'floor' for FT4 levels should be.....I guess the answer would be it varies between individuals and you just need to experiment.

[SlowDragon Administrator in reply to whatevs]

Yes some people are fine with low Ft4, like yours others, find that causes symptoms despite good Ft3

Your Ft3 isn’t Currently particularly good either

I don’t think anyone would choose to be on strictly gluten free diet, but for many Hashimoto’s patients it’s essential.

[SlowDragon Administrator in reply to whatevs]

Thousands of posts on here about gluten

Just came across this one

healthunlocked.com/thyroidu...