More on Ferritin and Folate

Low iron/ferritin:

Iron deficiency is shown to significantly reduce T4 to T3 conversion, increase reverse T3 levels, and block the thermogenic (metabolism boosting) properties of thyroid hormone (1-4). Thus, iron deficiency, as indicated by an iron saturation below 25 or a ferritin below 70, will result in diminished intracellular T3 levels. Additionally, T4 should not be considered adequate thyroid replacement if iron deficiency is present (1-4)).

See also Iron supplementation for unexplained fatigue in non-anaemic women: double blind randomised placebo controlled trial (5)

1. Dillman E, Gale C, Green W, et al. Hypothermia in iron deficiency due to altered triiodithyroidine metabolism. Regulatory, Integrative and Comparative Physiology 1980;239(5):377-R381.

2. Smith SM, Johnson PE, Lukaski HC. In vitro hepatic thyroid hormone deiodination in iron-deficient rats: effect of dietary fat. Life Sci 1993;53(8):603-9.

3. Zimmermann MB, Köhrle J. The Impact of Iron and Selenium Deficiencies on Iodine and Thyroid Metabolism: Biochemistry and Relevance to Public Health. Thyroid 2002;12(10): 867-78.

4. Beard J, tobin B, Green W. Evidence for Thyroid Hormone Deficiency in Iron-Deficient Anemic Rats. J. Nutr. 1989;119:772-778.

5. BMJ 2003;326:1124

Quote Originally Posted by reallyfedup

Is there medical papers that show that ferritin and folate need to be above halfway in their ranges in order to convert t4 into t3

24 Replies

  • I think you may find that it came from this site, which has a lot more very useful information.

    Moggie x

  • Thank you Moggie

    that link is vital inf to stick under noses of all the useless doctors and endos who refuse to treat people correctly

  • Well that's unambiguous and clear. Thank you :)

  • There will be a few very annoyed GPs and endos when faced with that research

  • You might want to stick the piece about dieting under their noses as well (found in the link) - I also found that very interesting.

    Moggie x

  • Hi

    My serum iron is 16 range 8.00 - 34.00

    Is this the same as saturation, I am a bit confused by it.

    Ferritin is 65 range 15.00 - 300.00

    Folate 9 <3 suggest deficiency

    Do I need to supplement.

    Best wishes browny

  • Ferritin is 65 in a range of 15 to 300

    therefore it is NOT halfway up its range so yes you need to take iron plus vit C for several months to bring it up to closer to 150

  • Thanks for your reply, maybe that's the reason I am not feeling too good, I was thinking of taking spatone with fruit juice or would I need something stronger.

    Best wishes browny

  • spatone works for some people and not others

    you are really best to take 500mg vit c tablets with whichever form of iron you choose

    theres no knowing how much vit c is actually in fruit juice

  • I've just started taking NDT, a bit first thing and a bit in the afternoon, but am working on my iron too (have been for a couple of months). But as my iron says to take in divided doses and I'm taking 3 a day, and the NDT needs to be taken 4 hours away from iron, I'm a bit stuck! Is it OK to take more than 1 iron tablet at a time or will it just be wasted?

  • clearly theres a limit as to how easily or fast the body absorbs iron

    i understand many things are better absorbed overnight so could you take the last dose of iron before bed along with vit c and any other vitamins /minerals

  • Yes, I could take it at night, I think it is best with food. Do you think taking it all in one go rather than divided would be a problem?

  • Thankyou

  • i think most people only take it once anyway and if you need to take it with food then lunchtime would seem best that should give enough space between it and NDT

    Since NDT has a greater proportion of T3 it may not matter quite so much as the iron levels are needed to convert T4 into T3

    Can you take your NDT sublinguinally because that way its absorbed directly into the bloodstream

  • Mmmm, not sure. It's Naturethroid. Will look into it, thanks

  • I was on 20mg iron in the past and my ferritin level was low at the time. GP did not put me on supplementation as they quoted me as being "borderline". So if someone with a low but normal T3 is taking T4 only does that mean that their ferritin and folate levels are bound to be low? What is this Reverse T3?

  • if ferritin or folate is below halfway in the ranges then the body has great difficulty converting T4 (thyroxine) into the T3 their cells need to function

    hence a free t3 reading is most likely to be useless reverse T3

  • reallyfedup123,

    Are you saying that a Free T3 test indicates the sum of T3 and reverse T3? So someone who should have, say, FT3 of 3 and rT3 of (and I can't think what number to put in here, I'll choose a number out of the air) 5 would get a result of 8? Would that be Free rT3 or Total rT3?

    I have never found anything that says that is the case so would be interested in any reference to it. I have always believed that the Free T3 test measures Free T3 and nothing else - though all tests have the potential for interference (e.g. it might happen from antibodies to T3 itself - though I am not at all sure that it does).


  • i need to check furthur but i have always understood that so called free T3 test could not be totally relied upon since it will include reverse t3 as well

  • Hi

    Sorry to jump in but I have just received my result from a 24 hours

    Urine T3 test.

    My Nutritionist arrange it for me to check if I was converting the T4 in my levothyroxine to T3. She said the result proved I was.

    It states Triiodothyronine (T3) 2394 range 592 - 1850

    but my blood test for T3 is 4.4 range 3.8 - 6.0

    T4 14 range 7.8 - 21.00

    TSH 0.10 range 0.35 - 4.70

    I am totally confused as the urine T3 is over range

    and blood T3 under mid range.

    Is this to do with reverse T3 if not what does it mean.

    Any advice greatly appreciated.

    Many thanks browny

  • I admit to not knowing

    i wonder if Sheila or others on would know

  • Hi

    Thanks, I have posted a question on tpauk.

  • The article you've quoted from doesn't appear to mention folate or folic acid levels and their affect on thyroid function. Can anyone point me in the direction of research that shows the need for folate levels to be above mid range? I keep reading on TUK that this is the folate level to go for for best thyroid function but can't find any evidence to show my GP.

  • I think i posted the folate article previously on this forum

    have you done a search using folate as the subject ?

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