B12 next steps - advice please

[GW1000]

Hi - I have also posted this in the Pernicious Anaemia section but I know there is also some good knowledge within this group too.

I have autoimmune hypothyroidism. Following a disappointing Endo appointment I wrote a detailed email to request an appointment with the Consultant as I felt I hadn’t had the chance to discuss my concerns properly with her junior. This was granted and I have been offered a trial of T3 - not started yet.

Informed by this forum I was also concerned about my B12 but was told they were unable to do any further tests as my serum B12 was normal. So I have privately tested for Intrinsic Factor antibodies (negative) and Active B12 (below range). 

I’ve had (I think..) full blood count done by the NHS - all normal, the other thing Medichecks recommend is a methylmalonic acid (MMA) test. 

I think I just need a bit of reassurance as to what to do next. I will contact both my GP and the Endo about the private test results and ask for an MMA test. Both admit to knowing little about B12. Am I likely to be able to get a test or will it require another referral to someone who does know about B12 ?! Should I be asking about anything else?

Immediately after doing the private tests I started taking sublingual B12 (4 days ago). Will this affect an MMA test? Should I stop taking it just now? 

My folate is also low so I was intending to also start taking a B Complex in a week or so. Think I will hold off on that just now. 

Any comments welcome - thank you!

Active B12    36 pmol/L (37.5 - 188)

Folate           12.4 nmol/L (8.83 - 60.8)

Intrinsic Factor Antibodies 1.05 AU/mL

<1.2 Negative

1.2 - 1.53 Borderline

>1.53 Positive(Range: < 1.2)

[SeasideSusie Remembering]

The MMA test, I think, should confirm if you have B12 deficiency. If you start taking B12 this will surely alter your B12 level. My understanding is no folic acid or B12 supplements until testing for B12 deficiency has been carried out.

However, the PA forum are more knowledgeable than me so will be able to offer better guidance.

[Titaniumfox]

MMA is a marker of AdenosylB12 deficiency, Homocysteine is a marker of methyl B12 deficiency.

[GW1000]

Hi again. I’m getting nowhere fast on this! The Endo has said the Active B12 test is out of her field so can’t comment. Do you think I’m right to continue to pursue the B12 issue before starting Liothyronine? I think I need to but just looking for some reassurance.

Many thanks