Thyroid UK
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Ferritin and T3


Can someone tell me if low ferritin inhibits the body’s conversion of T4 to T3?

I was diagnosed with hypothyroidism a little over a year ago and I am currently taking T4. Despite taking T4 my T3 levels have not increased. My hair fall is so bad it’s depressing, even my eyebrows have thinned. My Endo checked my iron and ferritin which were both low so my Endo put me on iron tablets.

I am now seeing a different Endo as I have changed locations and my iron levels are high, so they have stopped the iron tablets. The problem is my ferritin is only just in range and my hair is still falling out badly.

I understand that high iron levels aren’t good for you so want to know how else can I get my ferritin up without taking iron tablets?

I really want to reduce the hairfall and try to help the T4 to T3 conversion issue.

Appreciate any help! Thanks.

13 Replies

Eating liver once a week is good for ferritin

Do you have Hashimoto's also called autoimmune thyroid disease? Diagnosed by high thyroid antibodies

If so low stomach acid is common and then often results in low ferritin, B12, folate and vitamin D

Have you had other three tested? Post results and ranges if you have them

Are you adequately treated for thyroid?

TSH should be around, or just below one, FT4 towards top of range and FT3 at least half way in range

Add your most recent results and ranges and members can advise


Thanks for your speedy response.

I don’t have my latest results to hand. I will post them in here later or tomorrow AM.

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Blood results posted in comments


Do you have actual results and reference ranges for any of the following?


Serum iron

Iron panel

Full blood count


Vitamin B12

Vitamin D

If you do could you post them, please.

If your serum iron is high and your ferritin is low this may indicate you have a problem with methylation. Unfortunately, the methylation cycle is complicated and I don't really understand it. You could read up on it here :

Dr Myhill provides a protocol on that link (which is expensive, naturally :( ) that you can follow to get your methylation cycle running normally again. My very basic understanding suggests that you need to take B vitamins in their active forms rather than their inactive forms that the body has to convert, for example you need methylfolate rather than folic acid, and methylcobalamin and adenosylcobalamin rather than cyanocobalamin.

Once your methylation cycle starts running properly your body should (amongst many other things) start to use iron more normally. Your serum iron should drop and your ferritin level may rise.

But I'm making no promises - this really is a subject I have never really grasped.

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Avoid iron supplementation while you have high serum iron. You will probably just end up increasing your serum iron even further and your ferritin won't change.

With high serum iron you will deposit iron in your soft tissues, which is where the body a) can't get rid of it and b) can't use it.

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I think this is what has happened, my last bloods show that me serum iron is 162.9ug/dl and their reference range is 23-134

But my Ferritin is 30.2 and their reference range is 15-150.


my last blood tests show the same iron 163 with the same range. but after this i remembered that i took a b12 pill the day before the test. i repeated the tests after 1 week without any b12 and the iron result was 103, ferritin 43 with the same ranges as yours...


Thank you for your comments, I have posted my most recent blood results as a comment


Ok here is the breakdown of my latest results with the clinics reference range in ()

Info: Following the below results my Dr has reduced my T4 as he said my TSH is too low, my dosage was 100mcg per day he has now reduced to to 5 days per week at 75mcg and 2 days a week at 100mcg. He stopped my iron tablets as serum iron is too high (despite my ferritin still being in the lower end of range and the reason why I was put on them in the first place). Has given me Vit D supplements too.

Also no idea if it related to anything with my thyroid or has an impact in any way but my cholesterol is also high. Also other medical conditions which I have of which I have no idea if it has any relevance is PCOS and insulin resistance.

TSH 0.09 uIU/ml (0.38-4.31)

FT4 1.34 ng/dl (0.82-1.63)

FT3 2.47 pg/ml (2.17-3.34)

TG Antibodies <0.12 IU/ml (<13.6)

TPO Antibodies 0.10 IU/ml (<3.2)

Serum Iron 162.9 ug/dl (23-134)

Ferritin 30.2 ng/ml (15-150)

Vit D 24.95 ng/ml (deficient <10, insufficient 10-29, Sufficiant 30-100, potential toxicity >100)

Welcome and feedback and thoughts.

Thank you!


PCOS can be connected to hypothyroidism. I don't have a link but the following is a copy I made a while back when I saw it. It was written by a doctor who was also an Adviser to TUK before his untimely death:-

Multiple Ovarian Cysts as

a Major Symptom of Hypothyroidism

The case I describe below is of importance to women with polycystic ovaries. If

they have evidence, such as a high TSH, that conventional clinicians accept as evidence

of hypothyroidism, they may fair well. But the TSH is not a valid gauge of a woman's

tissue thyroid status. Because of this, she may fair best by adopting self-directed

care. At any rate, for women with ovarian cysts, this case is one of extreme importance.

In 2008, doctors at the gynecology department in Gunma, Japan reported the case of a 21-year-old women with primary hypothyroidism. Her doctor referred her to the gynecology department because she had abdominal pain and her abdomen was distended up to the level of her navel.

At the gynecology clinic she underwent an abdominal ultrasound and CT scan. These

imaging procedures showed multiple cysts on both her right and her left ovary.

The woman's cholesterol level and liver function were increased. She also had a

high level of the muscle enzyme (creatine phosphokinase) that's often high in hypothyroidism.

Blood testing also showed that the woman had primary hypothyroidism from autoimmune thyroiditis.

It is noteworthy that the young woman's ovarian cysts completely disappeared soon

after she began thyroid hormone therapy. Other researchers have reported girls with

primary hypothyroidism whose main health problems were ovarian cysts or precocious

puberty. But this appears to be the first case in which a young adult female had

ovarian cysts that resulted from autoimmune-induced hypothyroidism.

The researchers cautioned clinicians: "To avoid inadvertent surgery to remove an

ovarian tumor, it is essential that a patient with multiple ovarian cysts and hypothyroidism be properly managed, as the simple replacement of a thyroid hormone could resolve the ovarian cysts."[1]


1. Kubota, K., Itho, M., Kishi, H., et al.: Primary hypothyroidism presenting as

multiple ovarian cysts in an adult woman: a case report. Gynecol. Endocrinol.,

24(10):586-589, 2008.

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Your vitamin D is too low

40ng/ml minimum (presumably you are not in UK with those units of vitamin D)

You need B12 and folate measured too


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Following the below results my Dr has reduced my T4 as he said my TSH is too low, my dosage was 100mcg per day he has now reduced to to 5 days per week at 75mcg and 2 days a week at 100mcg.

TSH 0.09 uIU/ml (0.38-4.31)

FT4 1.34 ng/dl (0.82-1.63) --- This is 64% of the way through the range

FT3 2.47 pg/ml (2.17-3.34) --- This is 26% of the way through the range

TG Antibodies <0.12 IU/ml (<13.6)

TPO Antibodies 0.10 IU/ml (<3.2)

Serum Iron 162.9 ug/dl (23-134)

Ferritin 30.2 ng/ml (15-150)

Vit D 24.95 ng/ml (deficient <10, insufficient 10-29, Sufficiant 30-100, potential toxicity >100)

Your Free T4 is less than three-quarters of the way through the range, so the doctor can hardly complain it is too high.

And your Free T3 is only quarter of the way through the range, which is too low for most hypothyroid sufferers on Levo to feel well. Most of us need a Free T3 well into the upper half of the range, possibly even into the top third or quarter of the range.

You should not have had your Levo dose lowered, and in fact you would have done better to have had some T3 added to your dose of existing dose of levo. Low TSH does not mean that you are overdosed.

I don't know which country you are in, nor do I know what your options are with regard to seeing different types of doctors and/or buying different kinds of thyroid meds and/or self-treating. You clearly won't get anywhere with your current doctor, and may need to find another one.


Your iron problem may turn out to be easy or difficult, cheap or expensive to fix.

Chris Kresser has info that may help on methylation :

I wish you had info on your vitamin B12 and folate levels.

If your vitamin B12 is low I would have suggested trying 1 x methylcobalamin 1000 iU per day for a couple of months (until you had finished the bottle). About 2 or 3 days after starting methylcobalamin I would suggest adding in one a day of these :

If your B12 isn't low I would have suggested just taking the B Complex.

It is a much simpler way of dealing with methylation than most you are likely to find on the web. I have this awful feeling that an awful lot of people are being conned into trying lots of expensive supplements by lots of expensive nutritionists and functional medicine specialists. But as I said earlier I don't really understand methylation anyway.

The simplest protocol I found (sorry, I haven't got the link) is to just take 200mg or 400mg methylfolate per day and forget everything else - but I wouldn't do that unless I knew my vitamin B12 was at an acceptable level.


You need to get your vitamin D up higher. It needs to be roughly 40 - 60 ng/mL for good health. When taking vitamin D supplements (they must be D3 not D2) it is also essential to take vitamin K2 and magnesium as co-factors. Vitamin D increases absorption of calcium from the diet. Magnesium and K2 help that calcium to go into the bones not end up lining your arteries.

Look for "best and worst forms of magnesium supplement", read the advice from a few sites, and make your choice. Look into types of vitamin K2 as well.


Edit : Sorry, I feel a lot of the stuff I've written in relation to MTHFR (Methylation) is me fudging and hedging my bets and not being helpful!

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Thank you all for your responses. They are really helpful.

I am currently overseas and unfortunately I have limited access to good Drs. Also T3 is not prescribed here. It’s wa my understanding that no pharmacists stock it, however yesterday I was told that the government hospital does.

I need to check if that is correct and try to get a referral to the Endo there but it will probably take some time and even if the do have T3 I’m not sure how easily they will offer it.

Next time I get my bloods done which should be in a couple of weeks I will ask for my B12 and folate to be tested.

I hadn’t read anything about methylation but will do some homework on it now.

I am visiting the UK in 3 weeks time if anyone can advise to where I can purchase T3 online and have it delivered to the UK I’d greatly appreciate any insight.

Thanks again for all your responses, it’s amazing how knowledgeable you all are......more so than any Dr I have seen!


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