Has your daughter been diagnosed as 'hypothyroid'.
A more informative blood test is Free T4 and Free T3. Her T4 is bottom of the range (this isn't a Free T4) so she doesn't appear to have enough to convert to T3 and it is T3 that is the necessary hormone.
You will see from the following that your daughter seems to not have reached an optimum dose yet.
A Full Thyroid Function Test is TSH, T4, T3, free T4, Free T3 and thyroid antibodies. If GP wont do all, a private home blood test can be done. I'll give a link - just in case:-
Do you think that if she supplemented with iron tablets
In my opinion, no. It's over 70 which is the level said to be needed for thyroid hormone to work. Even though it's said that ferritin should be half way through range, I've seen it said 100-130 is good for females. As she has a reasonable ferritin level, and you don't know what her serum iron level is, or the other tests done in an iron panel - % saturation and transferrin - then if she already has a good serum iron level then taking iron tablets may take that too high. Too much iron is as bad as too little. If she can eat iron rich foods fairly regularly, say every couple of weeks, eg. liver, liver pate, black pudding, and include iron rich foods in her diet
Her FT4 is very low. A normal, low or slightly elevated TSH with a low FT4 can indicate Central Hypothyroidism which is where the problem lies with the pituitary or the hypothalamus. If it goes below range that would almost be a certainty. Central Hypothyroidism is nowhere near as common as Primary Hypothyroidism and many doctors haven't heard of it. She would need to find a proper thyroid specialist, not just an endo who specialises in diabetes.
Would recommend she get full Thyroid and vitamin testing privately as next step
Especially if there's Any autoimmune disease in the family?
For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also extremely important to test vitamin D, folate, ferritin and B12
Low vitamin levels are extremely common, especially if Thyroid antibodies are raised
Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and fasting. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)
Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies or all vitamins
Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have special offers, Medichecks usually have offers on Thursdays, Blue Horizon its more random
If antibodies are high this is Hashimoto's, (also known by medics here in UK more commonly as autoimmune thyroid disease).
About 90% of all hypothyroidism in Uk is due to Hashimoto's.
Low vitamins are especially common with Hashimoto's. Food intolerances are very common too, especially gluten. So it's important to get TPO and TG thyroid antibodies tested at least once .
That ferritin is fine. Don't supplement iron unless she has had a full iron panel done - but it is unlikely that iron is low when ferritin is good. High iron is often more dangerous than low.
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