Free Serum T4 levels low.: I had my thyroid... - Thyroid UK

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Free Serum T4 levels low.

Mino40 profile image
14 Replies

I had my thyroid tested last week. My TSH is down to 2.13 from 2.84. I’m on 75mcg Levo.

Interestingly, my free serum T4 is down from 14.1 to 8.0.

My GP hasn’t called me yet, but I am curious as to what this means, as normal is above 12.0.

Can anyone shed some light?

Thanks x

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Mino40
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14 Replies
greygoose profile image
greygoose

How long did you leave between your last dose of T4 and the blood draw?

Mino40 profile image
Mino40 in reply to greygoose

24 hours

greygoose profile image
greygoose in reply to Mino40

And you always leave 24 hours? You haven't started taking T3, have you? Apart from that, I cannot think of any reason why it would suddenly drop.

Mino40 profile image
Mino40 in reply to greygoose

Yes, I take my tests in the morning before I take my Levo. No, not taking T3. I just hope it’s nothing like pituitary-related hypothyroidism. I really shouldn’t Google stuff and sound like a hypochondriac! I’ll just wait and see if my Doc calls about it.

greygoose profile image
greygoose in reply to Mino40

The pituitary would affect the TSH, not the FT4. Do you have Hashi's?

Mino40 profile image
Mino40 in reply to greygoose

They never tested for it. My GP said no need, as I’m on Levo anyway.

DeeD123 profile image
DeeD123 in reply to Mino40

Might not make a difference to your doctor but it does to you. I would ask for antibodies to be tested as they can play havoc with results.

Mino40 profile image
Mino40 in reply to DeeD123

Thank you, I will ask.

Mino40 profile image
Mino40

My GP has called, he confirmed that my serum free T4 level is very low. The range is 12-22, mine is 8. My Levo is increased to 100mcg but he suspects after my next test (in 6 weeks), I’d have to go up to 125mcg. It seems so absurd that in January I was put on 25mcg with only a sub-clinical hypothyroid diagnosis with TSH 4.68.

SlowDragon profile image
SlowDragonAdministrator in reply to Mino40

Well once we start taking Levothyroxine TSH drops, so we are not making so much (or struggling to make) our own thyroid hormones

But also as metabolism starts to improve, we need more as well

Most patients need somewhere between 100mcg and 200mcg Levothyroxine

Essential to test vitamin D, folate, ferritin and B12 too. If these are too low they may need regular supplements to maintain at good levels

Mino40 profile image
Mino40 in reply to SlowDragon

You asked if was taking T3 & I don’t. I am curious as to why T3 will decrease FT4? Thanks x

SlowDragon profile image
SlowDragonAdministrator in reply to Mino40

No that was Greygoose

I would say your results are as expected. Dose of Levothyroxine is simply ready for increase.

Ask GP to test thyroid antibodies at next test, plus vitamins

Mino40 profile image
Mino40 in reply to SlowDragon

Would Hashi’s still show with Levo?

SlowDragon profile image
SlowDragonAdministrator in reply to Mino40

Yes. Testing for autoimmune thyroid disease is essential. Diagnosed by high TPO and/or TG antibodies

Low vitamins are even more likely with Hashimoto's plus many of us have hidden gluten or dairy intolerance

Most Medics currently ignore the autoimmune aspect, because there's no pharmaceutical treatment. But patients need to know as there is much we can do with diet change and supplements

Hashimoto's is as much a gut problem as it is thyroid

Essential to test vitamin D, folate, ferritin and B12. Always get actual results and ranges. Post results when you have them, members can advise

Hashimoto's affects the gut and leads to low stomach acid and then low vitamin levels

Low vitamin levels affect Thyroid hormone working

Poor gut function can lead leaky gut (literally holes in gut wall) this can cause food intolerances. Most common by far is gluten. Dairy is second most common.

According to Izabella Wentz the Thyroid Pharmacist approx 5% with Hashimoto's are coeliac, but over 80% find gluten free diet helps significantly. Either due to direct gluten intolerance (no test available) or due to leaky gut and gluten causing molecular mimicry (see Amy Myers link)

Changing to a strictly gluten free diet may help reduce symptoms, help gut heal and slowly lower TPO antibodies

Ideally ask GP for coeliac blood test first

amymyersmd.com/2017/02/3-im...

chriskresser.com/the-gluten...

thyroidpharmacist.com/artic...

scdlifestyle.com/2014/08/th...

drknews.com/changing-your-d...

thyroidpharmacist.com/artic...

But don't be surprised that GP or endo never mention gut, gluten or low vitamins. Hashimoto's gut connection is very poorly understood

Link about thyroid blood tests

thyroiduk.org/tuk/testing/t...

Link about antibodies and Hashimoto's

thyroiduk.org.uk/tuk/about_...

thyroiduk.org.uk/tuk/about_...

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