Diagnosis

[Angel-louise]

Hi is it possible to get a retrospective diagnosis by looking at blood tests overtime? I had raised MCV for many years. A low normal b12, injections normalised mcv, later high homocysteine and lots of clinical symptoms.

[Gambit62 Administrator]

There aren't any gold standard tests for B12D so all diagnosis really depends on looking at clinical presentations, which would include anaemia where relevant.

I think from the little that you say that you are probably actually experiencing poor diagnostic understanding.

B12 deficiency can be dietary if you have very low levels of B12 rich food in your diet - eg strict vegan or vegetarian with very little dairy in your diet.

If diet wasn't the cause then the problem must have been due to absorption problems - of which there are many.

99% of B12 is absorbed through the ileum and this is where things go wrong.

Absorption problems not only affect the initial absorption but also affect the mechanism that the body uses to recycle B12 (an extremely efficient mechanism that involves storing excess B12 in the liver and then releasing it through bile into the ileum where it is reabsorbed).

This means that if you have an absorption problem then there actually isn't any 'normalisation of B12 levels' - just a lot swimming around your blood stream that is gradually going to be lost through urine - how gradually varies from person to person, so if the symptoms are there then you are probably deficient again.

There is also a condition known as 'functional deficiency' where levels in blood are high but it is not actually getting through to the cell level so not there in a useable form. This tends to be caused by an autoimmune response to high levels of B12 in your blood stream. This may also be a factor for you as one study implied that the response occurs in about 30% of the population. There is very little out there on treating people with an absorption problem who have this response - though studies in Oxford imply that repeated high doses of B12 will work (presumably flooding the body with so much B12 that the autoimmune response can't destroy all of the TCII that transfers it to the cell level.

Other things that could be involved are also low folate levels - as the body needs folate to process B12 so it can get through a lot dealing with B12 shots and then levels will start to be too low for B12 to be processed properly.

You really need to go back to your GP, with a list of symptoms, and point out that if you have an absorption problem then you also have problems with recycling B12 and will need regular injections for life ... though if you are in the UK then the regime for maintenance shots may be a problem.

This is link to BCSH guidelines as there are different protocols for treatment if you have neurological involvement, from those if you don't.

bcshguidelines.com/document...

refer to summary for need to treat if neurological problems present

refer to p 8 for treatment protocols.

Getting through to GPs and even to specialists can be very difficult though.

This site may help with ideas on how to broach the subject

b12deficiency.info/

[Angel-louise in reply to Gambit62]

Many tx for detailed reply