references for ranges

[camomile9]

Dear admins, do you have references for position in ranges. My teenager is as you have pointed out, consistently less than 20% into range for fT4. Hypo symptoms. Taking her 100 mg daily for past year since I have been supervising. She is about 75kg so it should theoretically be 120mg anyway. She is not willing to be tested again currently so we just have to go on the last few results. If I am to argue the case for trying to up her meds slightly, are there any references to back me up? Thanks.

[SlowDragon Administrator]

Last test results

Ranges TSH 1.38 (0.35-5.0) FT4 11.2 (9-21)

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 at

[e-mail]

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...