What percentage is this T4 results?

[mstp]

Thia is my daughter's t4 result from a private health check she has just paid for. Her TSH was 4.5. I have been trying to persuade her to increase her levothyroxine given that her GP doesn't seem to know much but she has held off until now. She is going to her GP again now with me advising her to be prepared to stand her ground. Her blood test was done as per the thyroid healthunlocked protocol - first thing in the morning etc etc. Not sure how to calculate the percentage of this result though so she can argue her case. Any help gratefully received so I can advise her.

[greygoose]

It's 16% through the range, which is very low. Percentage calculator here:

thyroid.dopiaza.org/

And at 4.5 her TSH is much too high. So, her FT3 is probably very low, and that's the most important number as T3 is the active hormone needed by every single cell in the body. Did she have that tested?

[jimh111 in reply to greygoose]

Assuming the reference interval is 12 - 22 the result (16) is at the 40% point. This and the TSH indicate her dose should be increased if she still has symptoms.

[greygoose in reply to jimh111]

Oh zut! I muddled up the percentage and the result! Sorry, mstp! Thank you, jim.

But it's still too low!

[jimh111 in reply to greygoose]

Yes, I guessed that happened. Doctors don't realise fT4 has to be in the upper half when taking levothyroxine.

[greygoose in reply to jimh111]

There's a hell of a lot doctors don't realise!

[waveylines in reply to greygoose]

And endos too!! Lol....

[mstp in reply to greygoose]

No worries 😋

[greygoose in reply to mstp]

😘

[SlowDragon Administrator]

How much levothyroxine is she taking

Was test done early morning and last dose levothyroxine 24 hours before test

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

gponline.com/endocrinology-...

Graph showing median TSH in healthy population is 1-1.5

web.archive.org/web/2004060...

Comprehensive list of references for needing LOW TSH on levothyroxine

healthunlocked.com/thyroidu....

onlinelibrary.wiley.com/doi...

If symptoms of hypothyroidism persist despite normalisation of TSH, the dose of levothyroxine can be titrated further to place the TSH in the lower part of the reference range or even slightly below (i.e., TSH: 0.1–2.0 mU/L), but avoiding TSH < 0.1 mU/L. Use of alternate day dosing of different levothyroxine strengths may be needed to achieve this (e.g., 100 mcg for 4 days; 125 mcg for 3 days weekly).

Her results suggest she needs 25mcg dose increase in Levo and retest in another 6-8 weeks

[mstp in reply to SlowDragon]

Tes her tests were done correctly. She is currently taking 75 mcg.

[SlowDragon Administrator in reply to mstp]

So she must get dose increased to 100mcg daily and retest again after at least 8 weeks

Meanwhile working on low vitamin levels essential

Ferritin at least over 70

Test vitamin D, folate and B12 too

NHS easy postal kit vitamin D test £31 via

vitamindtest.org.uk

He folate was far too low in last test

Is she now taking daily vitamin B complex

Presumably her hypothyroidism is autoimmune

Is she in gluten free and/or dairy free diet

[SlowDragon Administrator]

Is this the same daughter’s vitamin results?

healthunlocked.com/thyroidu...

[mstp]

Yes her iron was still low but I have no numbers to look at. I have urged her to take some Three Arrows Heme iron.

[Insomania in reply to mstp]

I just looked at her previous results, her iron was rock bottom. I was there too a few years ago. I couldn’t tolerate iron tablets (digestive issues). I felt so unwell. I was really encouraged by this forum to push for a referral to haemotology and in meantime get an iron infusion privately. Good advice! It was/is iron deficiency anaemia. I get iron infusions on NHS if my ferritin goes near 30. My ferritin is around 145 now and my last iron infusion was Oct 2022. Tranexamic acid for heavy periods has helped with maintaining. Hope this helps.

[NanaV54]

You said that she is on B complex, which would contain biotin. Did she stop her B complex 7 days prior to her labs? Biotin doesn't harm the thyroid but it DOES give incorrect lab results. It will show TSH numbers lower than they actually are and FT4 and FT3 results higher than they actually are. It can also affect thyroglobulin results. Some sources say 2 days prior but many Drs recommend a week.

[mstp]

She isn't taking any B complex vits and says she feels ok which is probably why she is being a bit relaxed about tackling her iron and thyroid meds. Before crashing I think this is often the case though and I really want to prevent that happening because I know how difficult it is to improve after hitting rock bottom. I think this is why it took me so long to be diagnosed in the beginning. I just put feeling up and down emotionally to circumstances and as I had only ever experienced colds and flu at that point I didn't understand that it was possible to be ill and not be aching with a temperature. Thyroids are tricky arent they? We experience such a diverse range of symptoms.