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Thyroid UK
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LOW RT3/T4 ratio. Rest of ranges for last posr

TSH 0.90 mIU/L (0.27-4.2)

F Thyroxine 17.2 pmol/1 (12-22.0)

Total T4 90 nmol/L (59-154)

FT3 3.7 pmo1/ (3.1-6.8)

RT3 23 nd/dL (10-24)

RT3 Ratio *10.47 (15.01-75.00)

Thyroiditis Antibody

<10.0 IU/mL (0-115)

Thyroid Peroxidase <9.0 IU/ml (0-44)

7 Replies

Previous post for reference healthunlocked.com/thyroidu...

Surehope What about your vitamin and mineral test results?

Your TSH is in a good place, your FT4 is just very slightly over half way through range although your FT3 is low at just 16% through it's range.

At the moment, I wouldn't worry about your rT3/Ft3 ratio. Concentrate on improving conversion of T4 to T3. Your conversion ratio is 4.64 : 1 whereas good conversion takes place at 4:1 or less.

For good conversion to take place, all vitamins and minerals need to be at optimal levels, so post those and we can see if you are low in any. No point in considering the addition of T3 until all nutrient levels are optimal.

Also, supplementing with selenium l-selenomethionine daily can help conversion (200mcg is the normal dose).

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Thank you Seaside Susie . I've been taking for about three months Magnesium Chloride but only about half the recommended dose as it gives me loose bowels



As far as I know rT3 isn't taught in medical school and isn't usually tested in the UK so your endo may not know much about it.

This link suggests that levels of rT3 no more determine good health than TSH level does.


Your results are euthyroid (normal). TSH 0.9 is low-normal, FT4 17.2 is just over halfway through range, and FT3 3.7 is normal.

Thyroid antibodies are negative for autoimmune thyroiditis (Hashimoto's).

None of your results indicate any thyroid dysfunction.

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OK, so firstly, it doesn't matter about the rT3. All that tells you is that there's too much unconverted T4 in your system, so it's being converted into rT3 so as not to waste it - rT3 is then converted into T2.

The question is, why do you have too much unconverted T4 in your system? Well, obviously because it's not converting into T3 - but that has nothing to do with it not getting into your cells; don't say things like that to your doctors or they will think you know nothing and just dismiss you, you need to be taken seriously, and for that, you need to know what you're talking about.

So, why aren't you converting well? Could be several reasons : low-calorie diet, over-exercising, nutritional deficiencies, cortisol problem...

The first thing to rule out is nutritional deficiencies, but, I see you had them tested 7 months ago? So, then we need to look at cortisol, which is more difficult. Your doctor will only do an early morning blood test, which doesn't give you much information. Would you be willing to do a 24 hour saliva cortisol test? Of course, you'd have to pay for it yourself, but it will tell you a lot more about your adrenals than anything they will do on the NHS.

Did you manage to get the liver tests done that were suggested in your first thread? The bulk of conversion is done in the liver, so if there's a problem there, that could affect your conversion.

I notice you ask about self-treating in your first thread, which of course, is always possible. But, that won't get to the route of the problem. Seems to me, that before contemplating that, you should at least try to get to the bottom of this, because if the problem is with your liver, it could cause over problems further down the line, and taking self medicating with T3 could just muddy the waters, when it comes to getting a diagnosis for something else.

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Thank you Grey Goose. It's true I don't really know what I'm talking about and am just clutching at straws. I did get the liver tests done as suggested in first my first post and was told liver function was normal.

Liver function NHS blood test results this month:

Serum albumin 36 g/L (35-50g/L).

Serum Bilirubin level 8 umoI/L (3 - 21.00 umol/L)

Serum alkaline Phosphatase 68 iu/L (40.00-150.00iu/L).

Serum ALT level 14 iu/L <5500 iu/L

Serum Gamma GT level 16 (9.00-36.00iu/L)


OK, I don't really know anything about liver tests, so I'll have to take their word for it! lol

So, that only leaves the adrenals to investigate.

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Thank you very much GreyGoose snd Seaside Susie. This has cleared the fog a lot. So I need not go into the Endo begging for T3. I just tell him the symptoms and show the blood test results in the hope he'll do spend time thinking about conversion problems and I'll let him know also that I'm willing to pay for a 24 hour salvia and cortisol test. Once again can't really express my gratitude for your knowledge and willingness to give it.


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