Ferritin falling despite aggressive iron supplementation?

Hi - I've found this forum very helpful and have learnt a lot. I've worked up to a dose of 175mcg of thyroxine over the past 18 months. I've just had a load of blood tests and there are a few things that are concerning. The main issue is my ferritin has dropped from 20 (on my last test about 4 months ago) to 17 most recently, despite supplementing twice daily with vit c high elemental liquid iron on prescription. I've never had ferritin levels over 20 in 5 years of testing.

Also, the GP wants to put down my dose of thyroxine as I've gone from a TSH of 1.21 a few months ago to 0.02 most recently. However, this is the first dose that has halted some of my symptoms including hair loss, aching eyes and join pain. I'm still feeling knackered though although this is probably down to low ferritin.

My blood test results are:

TSH 0.02 (0.35 - 5) was 1.21 on 150mcg of thyroxine

Free T4 18.6 (9 - 21) was 20.6 on last test

Ferritin 17 (15 - 200) was 20 on last test

Folate 16.3 (3.1 - 20) I've been supplementing for last few months and it's gone up well

B12 621 (200 - 900) also been supplementing and it's gone up from around 400

Does anyone know why i can't maintain ferritin levels and that they are dropping despite supplementation? Also is my TSH too suppressed now? My haemoglobin is 14.1

Many thanks.

7 Replies

  • Do you know how much elemental iron you are taking per dose and per day? And how much vitamin C per dose of iron?

  • Hi Humanbean,

    I'm not sure on the amount of elemental iron - it was high though and only available on perscription. I took 5ml spoonful twice a day before eating and with vit c for the past 6 months. I'm really disappointed my ferritin has dropped. About 5 years ago I was rushed to hospital with a hgb count of 4 - they couldn't believe I could walk or talk. At the time they said I had severe iron deficiency. Iron supplements have got my hgb back up so I'm not anaemic but my ferritin is a struggle. I can't believe it's actually gone down! I don't want to keep taking iron if I clearly can't absorb it. I'm having more iron panel tests to investigate.


  • Your TSH is fine and GP shouldn't adjust your dose of levo only on the result of the TSH. Email louise.warvill@thyroiduk.org and ask for a copy of Dr Toft's Pulse Online article. In question 6 you will see how low we can go and he even says some of us need a suppressed TSH or the addition of some T3. (Ignore his last para as I think it is typical of many doctors). Give your GP a copy and he may take notice as it's from Pulse (doctors magazine).


  • Thanks Shaws I'll get a hold of the article. I dread being put on a lower dose.

    Do you know why my ferritin would have dropped despite high iron supplements? I feel pretty low about it and am feeling the effects of dropping ferritin. Feel a bit helpless as don't know what to do to sort it out.

  • It is a fact that if you are hypo you lose the ability to absorb iron. I also struggled for years despite heavy supplementation. Took about 400mcg a day for 6 years and nothing happened. Had an iron infusion and it went down again within the year. Try and cut out things that hamper absorption...like gluten.

  • Hi thanks for respinding Bluedaffodil. Its so frustrating and poor you. It's a bit of a worry as ferritin stores are so important. It is making me feel quite ill even though I'm on a good rhyroxine dose. I'm already gluten free and it hasn't made any difference. I'm shocked that it's actualky dropped after supplementation. I don't know what else I can do- I'll end up anemic again. What do you do to cope with it? Has it got worse and worse? Do you still supplemeny? I just wonder out there is some other underlying health issue.

  • Hi the doctor should not lower your levo with out you agreeing to it as well. It should be discussed between you both and if you don't agree then he/she should not lower it. your tsh is fine if you feel good.

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