Log in
Thyroid UK
91,912 members106,178 posts

Advice on hypothyroid, recurrent miscarriages and pregnancy. And do I need to make changes to vitamin supplements?


I am on 100mcg levothyroxine and have just had my latest blood test results back, 6 weeks after changing from morning to night time dosing.

These are my results:

TSH: 0.06 (0.27 - 4.20)

Free T4: 17.8 (12.00 - 22.00)

Total T4: 92.6 (59 - 154)

Free T3: 3.44 (3.1 - 6.8)

Thyroglobulin Antibody: <10 (0 - 115)

Thyroid Peroxidase Antibodies: < 9 (0 - 34)

Active B12: 227 (25 - 165)

Folate: 16.46 (2.91 - 50)

Vitamin D: 129 (50 - 200)

Ferritin: 49.8 (13 - 150)

CPR Inflammation Marker: 0.6 (0 - 5)

So, I think my T3 is far too low. What's frustrating is that it's gone down since my last blood test when I was taking my meds in the morning (it was 4.6 then - still quite low), though my T4 has gone up from 16.2 to 17.8...

I've never had my vitamins tested before but from what I can gather on this forum, my vitamin D is OK? I presume I should supplement with less B12? And should I be taking more folate to balance things out with B12? Is my ferritin a little low?

I supplement with folate, B12, vitamin D and iron, but clearly my dosages aren't quite right. Could my vitamin results explain why my T3 is so low?

I am seeing a private endocrinologist next week to discuss whether my thyroid issues could explain the constant miscarriages I am having. I am 39 years old so it might just be I am OLD! Is it worth me suggesting I take some T3? I know it's not recommended for pregnancy, but my metabolism is slow at the moment and I ovulate late every month, have a low temperature in the follicular phase and have a slow temperature rise after ovulation.

Any advice before I see this endo would be so much appreciated.

I would describe myself as a healthy, fit and active person though the lethargy (which I am sure is related to my low T3) makes it harder and harder to live the busy life I used to enjoy.

Thank you.

8 Replies

Sorry I forgot the range for my Free T3 result. It's 3.10 - 6.80.


Did you miss your night dose before your morning blood test?


Yes. Thought I was meant to do that?


Yes that's the right thing to do. :)


Miscarriages can occur in hypothyroidism when not on an optimum dose. The following link may be helpful.



Your FT3 is low. and FT4 could be higher.



Your results suggest you need dose increase in Levo (or the addition of small dose of T3 )

Total T4 is only mid range.

FT4 could be a bit higher

FT3 is too low obviously

How do you feel?

Your ferritin is on low side. If you like liver eating this once a week will help improve. Or you can buy OTC iron supplements

Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.

Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor

please email Dionne:

Prof Toft - article just published now saying T3 is likely essential for many


But medics are unhappy with T3 during pregnancy, so increase in Levothyroxine may be best idea

1 like

Thanks SlowDragon. That's really useful. I am aware of Dr Toft's articles and even took the one from which you quote to my GP a while back. She refused to look at it and just said she wouldn't contemplate a dose increase when it looks more like I am over-medicated due to low TSH... Anyway, this is why I am going to see a (hopefully) decent endo this week. I saw an NHS endo last year but he was also solely obsessed with my TSH so this time I'm trying a private one with a good rep.

I certainly think I'd benefit from T3 (though like you say it might not be right for pregnancy), and I'd also like to discuss NDT with the endo. I've heard some people have successful pregnancies with NDT after failing with T4. My concern is my TSH will be super suppressed with even more T4 and I already have low bone density...

I've read it may not be suppressed TSH that actually increases risk of osteoporosis, but might be more to do with low T3. That's a whole different discussion anyway!

I hate liver and am not a big meat eater! I already supplement with iron so will add a bit more. I am going to add some folate to my supplements too as that seemed on the low side.

In answer to how I feel; sluggish and tired! A shadow of the energetic person I've been before. Even all this messing trying to sort my thyroid meds out and having to constantly argue my case exhausts me! Sure many people on this forum feel that way.

Thanks again for your help.


Hi Emily,

Hope you're doing well. Have they tested your progesterone levels post-ovulation? Late ovulation itself isn't a problem at all, the same goes for low temperatures during the follicular phase. Progesterone is the hormone that raises your basal temperature post-ovulation and low levels may cause miscarriages. Obviously thyroid hormones have to be in good order, but lots of women have done well and had successful pregnancies when taking progesterone after ovulation and in the first trimester. Worth looking into.

PS! You're not too old!

1 like

You may also like...