B12 range - Dutch B12 deficiency organisation

[Dandelions]

In my search to understand my B12 levels better, I came across this article which I thought was interesting. stichtingb12tekort.nl/zou-i...

Sorry if it has been posted before or if there's an English version available.. I couldn't find them.

It mentions the overlap in B12 levels between B12 deficient patients and healthy patients and discusses diagnostic specificity vs diagnostic sensitivity when setting ranges for a lab test.

The article questions the common practice of setting a low range (150 pmol/l) for B12 tests This ensures no false positive results and gives what is called high diagnostic specificity. Because there's no severe harm in having false positives, high specificity is not needed. However, because false negatives could cause severe damage to a patient, setting ranges for high diagnositc sensitivity is actually required (and would be in line with (Dutch?) guidelines on how to set reference ranges). More so, because there's no risk of overmedicating if a positive result is false indeed.

In short, harm of missing patients with B12 deficiency is great; harm of falsely diagnosing B12 deficiency (eg. patient is healthy and not B12 deficient) is low. Therefore B12 test reference ranges should be set high to minimise the risk of missing out patients with a deficiency.

[SlowDragon Administrator]

B12 range in U.K. is too wide

Interesting that in this research B12 below 400 is considered inadequate 

healthunlocked.com/thyroidu...

[Dandelions in reply to SlowDragon]

Yes. Such a big difference betwee 400 and 150 isn't there!

I just thought it was interesting to see the explanation of why the range is too wide. And to understand the considerations that go into setting a range.

[SlowDragon Administrator in reply to Dandelions]

we always recommend anyone on replacement thyroid hormones keeps B12 over 500

[shaws Administrator]

My Mother had Pernicious Anaemia and had regular B12 injections until her GP - after a couple of years of B12 injections - told her she needed no more B12 injections as her 'blood' was fine.

Both my sister and myself thought that was 'good that no more B12 injections were needed;.

Unfortunately, due to the GPs advice my Mother developed stomach cancer and that was fatal and we had to plead for more pain relief towards the end of life.

I also have P,A. and have monthly injections. Previously I had one every 3 months.

GP said I can have as many as I think I need.

[Dandelions in reply to shaws]

It's utterly disgusting. And so very sad.

It underlines the argument in the article that missing B12 deficiency comes at great cost.

I'm booking another appointment with my Gp to request a PA test. I saw that it's 248 pounds at medichecks. So well worth asking GP for a 3rd time.

[shaws Administrator in reply to Dandelions]

Definitely request your GP to test P.A. as £248 is a lot of money especially if we're on a low income or a normal wage.

Don;t take B12 injection or B12 tablet before blood draw.