Fasting morning of blood test

[Springgreens]

Firstly, thank you all so much for being here! Reading this forum has given me the encouragement to go back to my doctor rather than give up at the first hurdle.

I have a blood test booked at the surgery for 9.20 on Monday. I'm quite happy to delay my Levo till after, but missing breakfast is likely to make me faint and risk getting a migraine so I think it best to eat breakfast at 8am as usual. (I usually take the Levo at 6am). Does this sound like the best plan? (I am being tested for TSH, T4, T3, B12, D, Folate, Ferritin, Calcium, Magnesium and possibly a few other vits and mins that I couldn't write fast enough to note.)

Doc is also testing for coeliac. I eat very little gluten, I mostly eat an organic whole food, largely vegan diet. For the test to work I think I need to have actually eaten gluten recently? I'm happy to eat a few slices of toast over the weekend - will that do the trick?

The background: Before Xmas I was getting fluttering sensations in my chest and a lot of anxiety so I contacted the doc who had me come in for ECG, blood pressure and took blood for a raft of tests. Talking to the doc and getting the tests done was very reassuring and the chest sensations and anxiety largely resolved by themselves.

However, the thyroid test, taken on 16th Dec 2020, came back:

TSH 7.21 (0.3-5.5)

T4 10.9 (12-22)

I've been feeling a bit under par for years - energy not as good as other people's, using willpower to get out for a 45 minute walk most days cos I know I'll feel worse if I don't, but not feeling any the better for it, not feeling rested after sleep etc. But it never seemed bad enough or specific enough to see the doc. However, when I got this result and there was a hope of being treated and feeling better I felt such relief I cried.

Doc wanted to repeat the test in 6 weeks. On 29th Jan 2021 it came back:

TSH 6.88 (0.3-5.5)

T4 9.9 (12-22)

Serum thyroid peroxidase antibody concentration 5 (<34)

Doc said I was borderline hypothyroid and started me on 50mcg Levothyroxine on 3rd Feb 2021. (I am 64)

Blood test 22nd March 2021:

TSH 4.38 (0.3-5.5) with the comment 'normal' (I didn't know then about fasting and not taking Levo before test, so had eaten and taken Levo that morning).

So doc prescribed more 50mcg Levothyroxine. We didn't actually get to speak and I just accepted the prescription, though I wasn't feeling any better and was getting worried that I might actually be feeling worse (achy muscles and joints) and starting to regret ever going to the doc in the first place (I rarely go to my doc and prefer natural therapies).

So I got onto the internet and found this forum, thank goodness! I educated myself both from here and other sources and feel much reassured about pursuing things with my doc. So I spoke to him yesterday on the phone and he wants to do another blood test, with TSH, T4 and T3. He wants to test for coeliac also. And when I said 'we haven't done vitamins and minerals yet have we?' he said he'd ask for B12, D, Folate, Ferritin, Calcium, Magnesium, and a few others, which seemed to cover a list I had made from this forum. So I am feeling reasonably confident that he and I can work together to get me as well as poss. I've never met him due to doing everything over the phone because of Covid, which makes it harder to establish a relationship, but I think we're doing as well as we can in the circumstances.

Thanks again for being here for us all!

[SlowDragon Administrator]

Levothyroxine doesn’t top up failing thyroid, it replaces it. So your ready for next 25mcg dose increase in levothyroxine

Unfortunately many GP’s don’t seem to read guidelines and think TSH anywhere within range is fine....it isn’t

TSH should be under 2 as an absolute maximum when on levothyroxine

gponline.com/endocrinology-...

Replacement therapy with levothyroxine should be initiated in all patients to achieve a TSH level of 0.5-2.0pmol/L.

NHS England Liothyronine guidelines July 2019 clearly state on page 13 that TSH should be between 0.4-1.5 when OPTIMALLY treated with just Levothyroxine

Note that it says test should be in morning BEFORE taking levothyroxine

Also to test vitamin D, folate, B12 and ferritin

sps.nhs.uk/wp-content/uploa...

Aim is to bring a TSH under 2.5

UK guidance suggests aiming for a TSH of 0.5–2.5

gp-update.co.uk/SM4/Mutable...

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)."

(That’s Ft3 at 58% minimum through range)

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 at

[e-mail]

What vitamin supplements are you currently taking?

Important to stop taking any supplements that contain biotin a week before all blood tests as biotin can falsely affect test results

[Springgreens in reply to SlowDragon]

Thank you SlowDragon. I don't take any supplements at present, so OK on that score. I'm thinking I might try to fast if I can, I'll see how I am feeling on Monday morning. Looks like I've missed the boat as far as the coeliac test goes - it seems to be recommended to eat gluten every day for six weeks before the test and I don't eat gluten much at all - but I really don't think it is a factor, and I guess it can always be revisited if necessary once I've got the Levo dosage and the vits & minerals optimised. I'll make sure my doc knows that the coeliac test results this time will be unreliable.