Thyroid UK
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Help interpreting blood results?

Hi there

I recently got my thyroid tested as I've had some health issues this year and have been struggling to lose weight despite diet & exercise. I've also had issues with hair loss, and am on Iron tablets for that. I am not currently on any other medication.

I just got the results back from the private lab, and the commentary is very sparse. I THINK these are all ok - but not sure about the T4, Vitamin D or Vitamin B12 Level - looks a bit on the low side potentially? Could someone help me to interpret them - as I say, I think they are probably normal and don't want to bother my GP if that's the case.

Vitamin B12 200 (pg/ml 197-771)

Folate (serum) 10.1 (ug/L >2.9)

Ferritin 54 (ug/L 13-150)

C reactive protein 3.5 (mg/L <5.0)

Total Thyroxine (T4) 89 (nmol/L 59 - 154)

TSH 1.76 (mIU/L 0.27 - 4.2)

Free Thyroxine 15.3 (pmol/L 12.0 - 22.0)

Free T3 4.1 (pmol/L 3.1 - 6.8)

25 OH Vitamin D 51 (nmol/L 50 - 200)

Thyroglobulin Antibody 17.0 (IU/ml 0-115)

Thyroid Peroxidase Antibodies 24.2 (IU/ml 0-34)


7 Replies

Just checking that you're not taking a multivitamin with B12 in it, nor any biotin (the former because your B12 is at the very low end of the 'normal' range and the latter because in some labs. it can interfere with your results for various technical reasons).

Your vitamin D is just scraping into the 'sufficient' range so you might well feel better if you can improve that.

How much iron are you taking?

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Thanks so much for your reply. I'm not currently taking any multivitamins (or vitamins of any kind) nor any biotin. I'm taking Ferrous Sulphate 200mg daily. I had a big operation earlier in the year with a blood transfusion, so just getting back on my feet after that.

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OK - it's not possible to tell whether you had low-in-range B12 before the surgery and this is your normal or, possibly, you had some nitrous oxide as part of your anaesthesia and this might have reduced your B12 level and it's struggling to recover.

I'm going to echo SlowDragon and say that you might want to take advice on assessing and improving your B12 from the PAS forum. Give your results and ranges there, and explain that you had this surgery etc. but you don't know if you previously had low-in-range B12 or if it's a response to the anaesthesia.

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Thank you again. I will take your advice and post my results on the PAS forum.


Article about low B12 following anesthetiser


Yes B12 is definitely on the low side. It would be good if GP did full testing for Pernicious Anaemia and intrinsic factor, especially as you are already low in iron but you might have a battle about that. You could post on PAS Unlocked for advice

Ferritin is fairly low considering you are on iron. Aiming for result of at least 70

Vitamin D needs improving to at least 70, but around 100 may be better

Vitamin D mouth spray by Better You is very good. Retest twice a year until you work out how much you need to keep at that level -£28 postal kit test

Perhaps you have low stomach acid- this reduces vitamin absorption. Common as we get older

Thyroid - no raised antibodies which is good, though TPO is creeping up, keep an eye on that

The TSH, FT4 and FT3 look ok

This may change as your vitamins improve. Would suggest retesting in 2-4 months once Vitamin levels are good

You might want to try gluten free diet see if it helps, might reduce The TPO antibodies too


Thank you so much for your helpful interpretation of my results. I'll go and see my GP regarding the B12 I think - not sure if they'll suggest injections or if I can just get a supplement? The reason my iron is low is that I had major surgery at the end of May, and had to have a blood transfusion as part of that - and my iron has been low since. I'm taking 200mg Ferrous Sulphate a day currently. Thanks for the recommendation of the Vitamin D spray - I'll get some of that for sure.

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