Help with Thyroid Blood Test Results please - Thyroid UK

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Help with Thyroid Blood Test Results please

Charltonjl profile image

Hi guys, I am 41 years old and had a baby 9 months ago. During my pregnancy, I developed an underactive thyroid and have been on Levothyroxine (25mg) since. I do not believe I need to stay on Levothyroxine so please can I have some feedback on my test results. I feel Levothyroxine has somehow made me gain weight too?! My doctor has told me to continue it because of my low Free T4 levels. Any advice welcome. Thank you :)

28 Replies
SlowDragon profile image

The trouble with a tiny dose of levothyroxine is it doesn’t top up your own thyroid replaces it

So being on tiny dose has caused your own thyroid to take a rest ...but your not on high enough replacement dose

Standard starter dose of levothyroxine is 50mcg

Suspect you may need to remain on levothyroxine....the only way to know is to stop taking it and retest in 8-10 weeks

See if TSH goes up and Ft4 and Ft3 drop further

You don’t have high thyroid antibodies

But vitamin D is too low.

Low vitamin D obviously needs improving and GP should prescribe 1600iu everyday for 6 months

Vitamin D

GP will often only prescribe to bring levels to 50nmol.

Some areas will prescribe to bring levels to 75nmol

GP should advise on self supplementing if over 50nmol, but under 75nmol (but they rarely do)

NHS Guidelines on dose vitamin D required

Once you Improve level, may need on going maintenance dose to keep it there.

Test twice yearly via

Vitamin D mouth spray by Better You is very effective as it avoids poor gut function. There’s a version made that also contains vitamin K2 Mk7

It’s trial and error what dose we need,

Government recommends everyone supplement October to April

Do you normally supplement through winter?

Also read up on importance of magnesium and vitamin K2 Mk7 supplements when taking vitamin D

Vitamin K2 mk7

Are you breast feeding?

Baby will need vitamin D drops if you are

Thank you so much for this! Yes I am still breastfeeding but baby also takes vitmins. I have been taking vit D supplements daily but only 1000iu. Maybe I need to take more than just 1 tablet? Hoping they aren't 'fake' as got them off Amazon. I will buy the spray you suggested. Thank you :)

ILR2019 profile image
ILR2019 in reply to Charltonjl

I was taking vitamin D tablets, but I have recently changed to a spray. I use Better You (it's available in different strengths, including 1000iu). It is cheaper to buy on Amazon than direct through company.

SlowDragon profile image
SlowDragonAdministrator in reply to ILR2019

Sometimes Better You also on 3 for 2 offer at H & B

The Better You vitamin D spray that includes vitamin K2 mk7 helps direct Calcium to bones

Vitamin K2 mk7

Sorry one more Q. Do I need a magnesium supplement when my results show that I have high levels of magnesium in my body? Thank you

SlowDragon profile image
SlowDragonAdministrator in reply to Charltonjl

Yes probably

Generally we need magnesium supplement if taking high dose vitamin D

Magnesium supplements must be four hours away from levothyroxine

Magnesium blood test is unreliable, plus you have high magnesium because vitamin D is low

Thank you so much xx

Your doct is probably right in having you continue as your T4 is barely in range, are these the first bloods you have had done since starting levo? Also i would hope they have put you on vit D aswell.

Charltonjl profile image
Charltonjl in reply to sbadd

They're the 2nd bloods but the others were similar x

SeasideSusie profile image


I do not believe I need to stay on Levothyroxine so please can I have some feedback on my test results. I feel Levothyroxine has somehow made me gain weight too?!

Why do you think you don't need to stay on Levo?

The aim of a treated hypo patient on Levo, generally, is for TSH to be 1 or below with FT4 and FT3 in the upper part of their reference ranges, if that is where you feel well.

Your TSH is too high, your FT4 is a measly 2% through it's range and your body is doing it's best to provide as much T3 as it can (the active hormone that every cell in our bodies need) by producing a level that's 25.41% through range.

You are undermedicated and that's probably why you're gaining weight.

You need an increase in your dose of Levo, 25mcg now, retest in 6-8 weeks to check your levels.

Your Vit D level is dreadful. The Vit D Council recommends a level of 125nmol/L and the Vit D Society recommends a level of 100-150nmol/L.

To reach the recommended level from your current level, based on the Vit D Council's suggestions you could supplement with 5,000iu D3 daily.

Retest after 3 months.

Once you've reached the recommended level then you'll need a maintenance dose to keep it there, which may be 2000iu daily, maybe more or less, maybe less in summer than winter, it's trial and error so it's recommended to retest once or twice a year to keep within the recommended range. You can do this with a private fingerprick blood spot test with an NHS lab which offers this test to the general public:

Doctors don't know, because they're not taught much about nutrients, but there are important cofactors needed when taking D3 as recommended by the Vit D Council.

D3 aids absorption of calcium from food and Vit K2-MK7 directs the calcium to bones and teeth where it is needed and away from arteries and soft tissues where it can be deposited and cause problems such as hardening of the arteries, kidney stones, etc.

D3 and K2 are fat soluble so should be taken with the fattiest meal of the day, D3 four hours away from thyroid meds if taking D3 as tablets/capsules/softgels, no necessity if using an oral spray.

Magnesium helps D3 to work. We need Magnesium so that the body utilises D3, it's required to convert Vit D into it's active form. So it's important we ensure we take magnesium when supplementing with D3.

Magnesium comes in different forms, check to see which would suit you best and as it's calming it's best taken in the evening, four hours away from thyroid meds if taking magnesium as tablets/capsules, no necessity if using topical forms of magnesium.

Don't start all supplements at once. Start with one, give it a week or two and if no adverse reaction then add the next one. Again, wait a week or two and if no adverse reaction add the next one. Continue like this. If you do have any adverse reaction then you will know what caused it.

Ferritin could also do with improving, it's recommended to be half way through range (82 with that range). You can help raise your level by eating liver regularly, maximum 200g per week due to it's high Vit A content, also liver pate, black pudding, and including lots of iron rich foods in your diet

Don't consider taking an iron supplement unless you do an iron panel, if you already have a decent level of serum iron and a good saturation percentage then taking iron tablets can push your iron level even higher, too much iron is as bad as too little.

Thank you so much. The private GP who analysed these results for me said my TSH is in range? I'm very confused. Do I request a higher dose of my meds from my GP then? This is all new to me. I currently only take 1000iu daily so will up my vit D. Thanks for all the advice :)

SeasideSusie profile image
SeasideSusieAdministrator in reply to Charltonjl


The private GP who analysed these results for me said my TSH is in range?

The doctor's comments that came with these results? This looks like a Blue Horizon test.

Those doctors are the same as any NHS doctors, they only go by TSH. You've been told that your results are in range because they are. But "in range" doesn't mean optimal and I mentioned above where most hypo patients need their levels to be to feel well.

Don't bother with doctor's comments with any private tests. You can always put your results on here and get a proper interpretation of them, not have them interpreted by someone who's had it drummed into them that TSH is the holy grail, it isn't, the way you know if you are optimally medicated is by eradication of your symptoms and the thyroid hormone levels - FT4 and FT3 (TSH is not a thyroid hormone, it's a signal from the pituitary) - and FT3 result is the most important one of all. Unfortunately doctors don't seem to know this.

Wow I've really got a lot to learn. Thank you. I will do my own research. So glad I found this forum ☺️

SlowDragon profile image
SlowDragonAdministrator in reply to Charltonjl

What were your thyroid results BEFORE starting on levothyroxine?

I'm unsure as I only developed the condition during my pregnancy last year and it was the hospital who tested me. Since then, all my bloods seem to have similar results :( Thanks x

SlowDragon profile image

What were the thyroid results BEFORE GP started you on levothyroxine?

I'm unsure. It was the doctors at the hospital during my pregnancy who put me on Levothyroxine. My GP told me to continue it as my Free T4 was on the lower end when I was tested a few months ago. I paid for this private test this week. I am unsure whether to stop the Levothyroxine for a few weeks and retest or to request a higher dose of it?? Thank you x

ILR2019 profile image
ILR2019 in reply to Charltonjl

You can obtain copies of your blood tests for free from your GP or by accessing your medical records online. It is definitely worth having access and taking the time to see what historical tests were conducted.

When GP say 'normal' results they are only referring to your levels being somewhere in normal lab range (which I believe is based on a healthy population and differs from lab to lab). It is where you are within those ranges and how you feel that matters. Normal doesn't mean optimal. If results truly were normal you would feel better.

I think you may have a long road ahead. Thyroid disease is dreadfully misunderstood and treated, but you will have excellent advice within these forums and it won't take long to understand the tests, results, treatment etc.

Charltonjl profile image
Charltonjl in reply to ILR2019

Oh I hope so thank you :)

Charltonjl profile image
Charltonjl in reply to ILR2019

Do you think I should ask for a higher dose of Levothyroxine then? Thank you x

SlowDragon profile image
SlowDragonAdministrator in reply to Charltonjl

I think you need to get hold of these records from hospital before making a decision

At the moment the levothyroxine is reducing TSH and as is such small dose it’s not giving enough to increase low Ft4 and Ft3

Normally once you start on levothyroxine it is for the rest of your life

dose would need to be increased slowly upwards in 25mcg steps ....retesting 6-8 weeks after each dose increase....until on full replacement dose (usually around 1.6mcg per kilo of your weight)

So you have two options

1) Try stopping levothyroxine and retest in 6-8 weeks ...see what happens to TSH, Ft4 and Ft3

If TSH goes up and Ft4 and Ft3 go down, then you definitely do need levothyroxine. You could/should then start back on 50mcg (as it’s the standard starter dose)

2) you see GP to discuss increasing dose to 50mcg ...Retesting in further 6-8 weeks......Repeat this step until on full replacement dose

What you can NOT do is just stay on 25mcg levothyroxine’s not enough for a mouse

You can work out your own vitamin D supplement dose using this link :

Just enter the details you have and click on Calculate.

Make sure to always buy vitamin D3, not vitamin D2.

Charltonjl profile image
Charltonjl in reply to humanbean

Thank you x

SlowDragon profile image

our thyroid controls our metabolism

As an example....if, when perfectly healthy, your own thyroid made the equivalent of 125mcg levothyroxine....and this metabolism is controlled by pituitary sending messages - TSH (Thyroid stimulating hormone)

Then as your thyroid starts to fail (usually due to autoimmune thyroid disease) might get diagnosed when your thyroid has reduced output to roughly equivalent of 75mcg levothyroxine

Pituitary has noticed there’s a drop in thyroid hormones in the blood....(that’s Ft4 and, most importantly, the active hormone Ft3) to try to make more thyroid hormone ...pituitary sends out stronger message to thyroid - TSH rises up

When GP starts you on 50mcg ....initially you feel a bit better you have 75mcg from your own thyroid and 50mcg levothyroxine

But (here’s the bit many GP’s don’t understand)....levothyroxine doesn’t “top up” your own thyroid output.....well it does very briefly....but the pituitary very soon “sees” the levothyroxine in the blood....and TSH starts to drop

So at the end of week 6 ....TSH has dropped a lot. Your thyroid takes a rest ....has a holiday

So at this point you are now only mainly using the 50mcg levothyroxine....which is actually a dose reduction down from managing on 75mcg from your own thyroid before you started on levothyroxine

So you start to feel worse .....and are ready for next 25mcg dose increase in levothyroxine

Even if we don’t start on full replacement dose, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until on full replacement dose

guidelines on dose levothyroxine by weight

NICE guidelines on full replacement dose


Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

Traditionally we have tended to start patients on a low dose of levothyroxine and titrate it up over a period of months.

RCT evidence suggests that for the majority of patients this is not necessary and may waste resources.

For patients aged >60y or with ischaemic heart disease, start levothyroxine at 25–50μg daily and titrate up every 3 to 6 weeks as tolerated.

For ALL other patients start at full replacement dose. For most this will equate to 1.6 μg/kg/day (approximately 100μg for a 60kg woman and 125μg for a 75kg man).

If you are starting treatment for subclinical hypothyroidism, this article advises starting at a dose close to the full treatment dose on the basis that it is difficult to assess symptom response unless a therapeutic dose has been trialled.

A small Dutch double-blind cross-over study (ArchIntMed 2010;170:1996) demonstrated that night time rather than morning dosing improved TSH suppression and free T4 measurements, but made no difference to subjective wellbeing. It is reasonable to take levothyroxine at night rather than in the morning, especially for individuals who do not eat late at night.

BMJ also clear on dose required

In your case you don’t appear to have autoimmune thyroid thyroid antibodies aren’t high .....however 20% of Hashimoto’s patients don’t ever have high thyroid antibodies

An ultrasound scan of your thyroid might help with diagnosis of Hashimoto’s and help you make up your mind wether to stop or increase dose of levothyroxine

Thank you so much for this x

Can anyone provide a suggestion of how to approach my GP about increasing my Levothyroxine dosage? She's very old school. Thank you

SlowDragon profile image
SlowDragonAdministrator in reply to Charltonjl

Print out those links I gave you

NICE guidelines

GP update


All say guidelines on dose by weight

Will do. Thank you again :)

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