Thyroid UK
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Blood results

Hi. After my recent flare up I was sent to pathology for up to date bloods.

I take 100mcg Levothryoxine daily.

Vitamin D3 2000 iu daily.

No meds were taken on the morning of draw.


B12 609 (197-866)

Serum folate 7.5 (4.6-18.7)

25-OH Vitamin D 61.3

TSH 0.36 (0.2-4.2)

Free T4 15.3 (12-22)

Free T3 4.1 (3.95-6.8)

Iron 12 (8.8-27.0)

Iron saturation 20 (20-40)

APRIL 2014

TSH 0.48 (0.2-4.2)

Free T4 15.3 (12-22)

Free T3 4.0 (3.95-6.)

I can see that my Free T3 is on the low range, does this correspond that I am not converting T4 to T3 sufficiently? The Free T4 also appears on the lower side, what does this mean please?

Thanks in advance :)

7 Replies

Wired, High FT4 and low FT3 usually means there is a conversion issue.

You need a higher dose of Levothyroxine to improve FT4 and FT3 or the addition of some T3 to improve your FT3. Either will probably suppress your TSH.

Dr. A. Toft discusses dosing and blood levels in the link below. email louise.warvill if you want a copy of the Pulse article to show your GP.

B12 is fine but folate is a bit low. A B complex supplement will give you the RDA of both.

VitD is optimal at 75-200 so I'd up your supplement to 3,000iu daily.


Thank you Clutter.

Could you recommend a complex B supplement?

A locum GP did say that I could increase my Levo to 125mcg a few months back, but I didn't take the extra. I have a prescription for it, so may just adjust my dose up to the 125mcg now.


Wired, I just buy a supermarket brand B Complex. Yes, try 125mcg and that will hopefully improve FT4 and FT3.

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Difficult to say if you're converting or not because you don't have enough T4 to convert. Both FT4 and FT3 are well below mid-range, so an increase in Levo would give you a better idea of whether your converting or not.

Hugs, Grey


Thanks Grey. I was wondering if I do take an extra 25mcg of Levo, won't it also lower my TSH levels a bit more. Would that possibly send me hyper?


It isn't your TSH level that determines whether or not you are hyper. It is your FT3 level that determines that, so if your FT3 ever goes over the range then is the time to consider reducing your meds. You probably won't get a doctor to admit that though - they are all totally fixated on TSH. There are people who can't tolerate FT3 when it gets high in range. But I suspect most people who feel comfortable with a mid-range or low in range FT3 won't feel the need to use this forum.

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You're a long way off 'hyper'! However, it might make you feel well. Or better, in any case.


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