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Thyroid UK
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1st ever blood test results, help for a novice please!

Blood test done on 9/5/13;

Serum free T4: 4.6 (11-24)

Serum TSH level: >100 (0.35-4.5)

Serum Vitamin B12 level: 233 (>180)

Serum ferritin level: 9 (13-150)

Serum folate level: 11.2 (4.6-18.7)

I was immediately put onto 100mcg of levothyroxine and iron tablets.

Just not sure what all the different things mean, so I know for my next set of results which I will get on Friday.

7 Replies

Hi. You are very hypothyroid and have very low stored iron (ferritin) so your doctor has done the right thing. You will probably eventually need a higher dose of thyroxine but you will probably not feel properly well until your ferritin is above 50 and nearer to 70-90. If you find you start to feel wire-but-tired or have a high heart rate or palpitations on this dose of thyroxine, it is more likely that it is due to your low ferritin level rather than too much thyroxine. Hopefully you will be fine though :)

T4 is thyroxine. This is very low which is why you need to take levothyroxine tablets. Because this is low, your TSH (thyroid stimulating hormone) is high to compensate.

Ferritin is your stored iron. It is best around 70-90 for most people. Good stored iron levels are important for your body to use thyroid hormones effectively.

Folate is folic acid, one of the B vitamins.

Your B12 is low in range. You will almost certainly benefit from a B12 supplement. I take 5000mcg methylcobalamin which is the most easily absorbed and used form of B12. This has really helped me.

You might find these pages on the main Thyroid UK website useful;




I hope this helps :)

Carolyn x


Thanks very much! Starting to make a bit more sense now, although I wasn't quite expecting the results to be that bad!


100mg of levo is really high as a starter prescription, mine started on mg and gradually built up to 75mg. Your Gp sounds thorough, mine just do the very basis of tests i.e. TSH level...


I was started on 25mcg of levo with a TSH of 100 and the Professor of Endocrinology said it should have been 50mcg starting.


Hi, just thought I would mention in case you were not aware - that you should not take the iron and the Thyroxine together, You have likely been told to take the thyroxine in the morning, and if it suits you to wait about an hour before having your morning cuppa and your breakfast, that's fine. (You should only drink water with the thyroxine).

I have found, like many on this site, that I get on better by taking the thyroxine last thing at night with water, because it is two or more hours since eating and it seems to be more effective. I can then have my first cuppa when I wake, and I can take my other meds then.

Starting on such a high dose could well be a bit of a shock to the system, but if you feel fine that is not a problem, - but remember, if you have any symptoms you don't understand, don't hesitate to put a question on here.

Good luck in your thyroid journey, you are in the right company, we are all on the same road.

Marie XX


I found out on here about the iron and thryoxine and waiting an hour to eat etc. so I've been doing all that. Might think about starting to take it at night though.

When I first started taking it I did feel very unwell, headaches and some fast heart beat, but it did settle down within a week.

Thanks very much for your help.


Okie dokie sounds like the plan to start taking the tablet last thing at night, I need my cuppa 1st thing in the morning.


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