MMA tests

Don’t you think that they should just stop doing b12 blood Serum tests and Instead just do a MMA test right at the outset and why on earth are they testing people who are supplementing ,of course they are going to have high levels in their blood so isn’t it time they stopped this old fashioned blood serum testing and test for active b12 and MMA.Other than maybe costs involved is there a reason they don’t consider this?

[fbirder]

It's because the serum B12 test is cheap, easy and perfectly good - if the doctor knows how to interpret the results.

The problem is that most tests that doctors do have well defined normal and abnormal results. If they test for haemaglobin then the result will give the doc a very good idea as to whether you're anaemic or not.

But the serum B12 test doesn't give such clear cut results. There is, indisputably, a grey area. Take Hull and East Yorkshire (HEY). They have a sensible testing regimen for B12. hey.nhs.uk/wp/wp-content/up...

They worked out a lower level of B12 of 115 pmol/L and an intermediate range of 115 to 150 pmol/L. They used these to try an reduce the number of people without a deficiency to a minimum. Some people can manage to survive on levels of B12 that would mean a deficiency in other people. HEY set their level at 115 pmol/L as that would only classify about 3% of the normal population as deficient.

If they set the lower limit higher then they would classify more normal people as deficient. Which would be a massive drain on resources. Here's why.

Let's assume that a B12d requiring treatment is present in 5% of the population. So 95% of the population aren't deficient. Take 10,000 people at random. 500 will have a B12d. 9,500 will not. Using HEY's limit 285 of those people will test below the bottom of the range. That's a lot of people being given injections unnecessarily.

If HEY had set the bottom of the range at 150 pmol/L then 1045 people would have been found to be deficient. Two-thirds of your patients being treated for a B12d wouldn't actually be deficient.

So HEY have the policy of -

1. Everybody with B12d symptoms and a serum B12 below 115 pmol/L is deficient and needs injections for life.

2. Everybody with B12d symptoms and a serum B12 between 115 and 150 pmol/L is started on a course of injections and has a test for IF antibodies. If they test positive for IFAB or the injections improve their symptoms, then they have injections for life.

They are using the one gold standard for a B12d - does the patient improve with injections?

They don't need Active B12 , which has the exact same problems as the serum test - some normal people will be below the normal limit, some deficient people will be above it. They don't need MMA - and there are multiple causes for raised MMA.

They need people who understand the limitations of the serum test and people who know that response to B12 injections is the gold standard.

I cannot understand why more people don't follow their lead.

[Hidden in reply to fbirder]

Great post thank you for that.

[Cherylclaire Forum Support in reply to fbirder]

...While I am relieved that they don't.

Response to injections ? I didn't ever know whether the nurses had done them or not at all for 10 months, as I couldn't feel a thing. The reason for the change finally? I was reloaded at 2 injections a week for 3 months by this point. A first response - small but very welcome.

For some people, response to injections can take a very long time, especially once loading is complete and having to wait 3 months for the next injection. Some people actually deteriorate badly at this point.

There is still the same problem - that age-old nuisance of human refusal to react identically.

So even in this, some people will react positively straight away and some will struggle - until they realise that they need more B12 than they have been given and for longer before any response can occur.

What we need is more research into the reason why this is true, less mucking around with cut-off points. Let us hope that the PAS research is resumed at some point, so that we can finally get some answers.