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Thyroid UK
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Blue Horizon Test Results

Hi all,

After a slightly traumatic time getting the blood sample required for the test, I have the results back so any comments would be great as, although I have been reading a fair bit, I still don't completely understand where in the ranges is the best place to be for each hormone.

CRP H 4.40 <3.0 mg/L

Ferritin 50.5 20 - 150 ug/L

Thyroid Function

Free T4 14.33 12 - 22 pmol/L

Free T3 4.95 3.1 - 6.8 pmol/L

TSH 1.75 0.27 - 4.20 IU/L

T4 Total 130.6 64.5 - 142.0 nmol/L


Anti-Thyroidperoxidase abs 12.5 <34 kIU/L

Anti-Thyroglobulin Abs 15.2 <115 kU/L


Vitamin B12 429 Deficient <140 pmol/L Insufficient 140 - 250 Consider reducing dose >725

Serum Folate 38.26 10.4 - 42.4 nmol/L

Thanks :)

32 Replies

Hello mooregibbs,

Lucky you...NO thyroid antibodies so NO Hashimotos.

CRP slightly raised indicating inflammation in the body.

Re thyroid hormones - As you are not medicating I think your results look ok although T4 is quite low.

B12 too high but I think that is good.

Folate looks good.

Ferritin is too low.

I don't know what to suggest mooregibbs but others will give their opinions too and advise on supplementing.

Good luck



Flower, about the B12, please read the answer I gave to Jazzw below, and tell me what you think.


Mooregibbs, you mentioned in your first post that you've been taking B12 - how much and for how long?

On the face of it, what you were afraid would happen - that the blood test wouldn't show a thyroid problem - is the case. But I'm not so sure that your B12 result is giving the right picture - it may be looking artificially high. Another clue is your lowish ferritin - you are somewhat anaemic, which won't be helping.


I'm not convinced that you have read the B12 result correctly, but maybe it's me who has got the wrong end of the stick.

"Vitamin B12 429 Deficient <140 pmol/L Insufficient 140 - 250 Consider reducing dose >725"

If I re-write this the way I think it should be read, it looks entirely different.

Vitamin B12 429

Deficient <140 pmol/L

Insufficient 140 - 250

Consider reducing dose >725

I think the result is 429 and the rest of it is just explaining the reference range.


If I confused things there, sorry. :)

All I was getting at is that if Mooregibbs has been taking high doses of B12 for two months, the result of 429 might not show the right picture - she might actually be B12 deficient despite that result (apologies if you're "he" not "she" - there's no gender on your profile. :) )

I guess, like Mooregibbs, I'm trying to find an explanation for the hypothyroid type symptoms if she isn't hypothyroid, and B12 deficiency would fit the bill.


Do you know how/why supplementing can mask deficiencies?


Thank you for the link.


Agree B12 could be much higher.


Yes agree with you humanbean. That is how I read it.

429 is high but I don't think it matters.



I think I've completely lost the plot here. There's something I'm missing and I simply can't see what it is. We tell people often that B12 is good around the 1000 mark. So how can a level of 429 be considered high?


It isn't, is it? We usually say anything less than 500 isn't great and that supplementing would be a good idea. And there'd be no need to reduce if the level was over 700 and wotsit, cos you can't overdose on B12. Odd thing to put in a reference range really!


humanbean & Jazzw,

Lol.....the Vit B12 saga continues...... & no

you are certainly not losing the plot humanbean.

I said ..[......Vit B too high (meaning as per strange test definitions) BUT I think that is good......] meaning 429 was NOT too high as strange test definitions indicated.

Why would someone even write such strange test definitions.. .?? Perhaps to confuse and cover all eventualities....Lol.



Yep, totally agree with yiu Humanbean - 429 is

not high - it's good ! Infact it could go higher

in ref range & be good. 700 plus I would consider

as high in range.


B12 is below 500 therefore too low as below 500 you can experience neurological damage. The rest of the range explanation is just waffle.

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I think what jazzw is referring to is your B12 level might be artificially high through over supplementing but this may not be the true level available in your blood for use.

B12 can be measured as active (usable ) and inactive (unusable).

The link below gives details on the "active B12" test. This may be worth persuing because there appears to little other reasons for your symptoms (except low ferritin that does requires supplementing) and may show a possible B12 deficiency.




If a person is supplementing b12, and takes the active b12 test, will it show up if they are deficient? I am concerned that I have some symptoms of b12 deficiency, but am too scared to stop supplementing in case the symptoms get worse. Sorry to jump in on this thread, but I am very interested in finding an accurate b12 test.


What jazzw was saying was by supplementing you are not achieving a true picture of the B12 circulating in your blood stream because you have added a load to it.

What I thought jazzw was saying was there are two different measurements for B12 ...active and inactive.

Only the active is a true measurement as only measures the usable B12 in your blood stream. However I feel this would be skewed too if supplementation had taken place.


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Yes. :) Sorry if I muddled anyone - I'm a tad sleep deprived today after one of those nights where my brain just wouldn't switch off, so I'm a bit off my game at the moment!

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Thank you. It is a gamble then, to find out if you are deficient you need to stop supplementing and risk further damage. That's what I thought, but not really sure if I should. Thanks for your help.


MidnightBlue, it's said that only 20% of serum B12 result is available for use so a baseline result low in range means it is possible to be deficient even within range. Japan considers neuropathy can be experienced <500. B12 >500 is unlikely to be deficient (whether naturally 500 or by supplementing). PA Society say 1,000 is optimal.


That is so helpful to know, thanks Clutter. In that case I will ask my GP to test b12, and see where in the range it is. Thanks again.



There is little point in stopping as previous supplementation will still skew results.

Most need to supplement, especially those with health conditions.

It is hard to take too much B12 so it is assumed sensible to supplement.

I had a high B12 blood serum and "B12 Active" result but still supplement as have a large risk on methylation impairment (genetic testing) and have previously suffered neuropathy in feet and hands.



Thanks, I will do.


Midnightblue, I can't see the point of baseline testing other than the initial B12 test. Most people supplement on the basis of a low B12 result and the supplement will prevent them becoming deficient. My B12 was low in Oct 13 and >700 in Feb 14 after supplementing. I supplement 1,000mcg daily so haven't bothered to have it retested.

If the B12 result showed deficiency the patient should have been investigated for pernicious anaemia before being given B12 injections to restore levels. If deficiency was due to diet, ie vegetarian or vegan, daily supplementation is required to overcome dietary deficiency.


I am vegan, so will be diet deficient, so I have supplemented, but lately have not really bothered. I have now developed a slight ringing in one ear, which it seems could possibly be related to b12 deficiency. I don't want it to get worse, so have panicked a bit and rushed back to my b12. I am just worried that I may mask an underlying problem like PA. I looked at the PA forum, and I don't think I have any other symptoms like numbness, tingling or breathlenses.


Midnightblue, those are symptoms of B12 deficiency, which can be caused by dietary insufficiency or PA. I'd assume your diet to be responsible, supplement for a few weeks and wait for the ringing to resolve.


Thanks again, I am taking 2 x 1000 a day, so hoping to see an improvement.


The active B12 test is the B12 at cellular level - best test I

believe. And as already at cellular level, believe supplementation

doesn't interfere with result, as with the total B12. Just my



Make no assumptions. Ask the lab that is doing the test. Don't believe anything you read on any website - only the lab doing YOUR test would matter.

For one example, Biolab say:

Patient preparation

Patients should refrain from taking nutritional supplements for 24 hours before venipuncture. If supplements containing vitamin B12 have been taken in the month prior to venipuncture, details should be given on the request form.

Recent i.m. B12 therapy may also complicate interpretation of the results.



Helvella - that link was a real useful read - thank you.


Mooregibbs, you are currently euthyroid. TSH low-normal, FT4 low-normal and FT3 almost in the top third of range.

Japan considers neuropathy can be experienced with B12 <500. B12 >500 is unlikely to be deficient (whether naturally 500 or by supplementing). PA Society say 1,000 is optimal.

Serum folate is high in range. There's no problem when folate is high as long as B12 is normal.

Ferritin is a bit low. Halfway through range is optimal. Supplement Ferrous Fumarate wth 500-1,000mg vitamin C to aid absorption and minimise constipation.


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