MMA and Homocysteine testing B12 whilst on injections...

[jw44]

I am 30 weeks pregnant. I am on monthly B12 injections, vitamin D pills and have had two iron infusions in the last couple of months. However, my most recent blood work (3 weeks ago) came back still showing anemia (and I am feeling pretty grotty too):

Haemaglobin: 118 (range 120-150)

RBC Count: 3.74 (range 3.8-4.8)

White cell count: 11.35 (range 4-11)

MCHC: 311 (range 315-345)

MCH: 31.6 (range 27-32)

Transferrin Sat Index: 32% (range 16-50)

Serum Ferritin: 378 (range 10-200)

I am assuming my iron levels are now OK following the transfusions, but am wondering about more frequent B12 injections. The consultant wants me to repeat my bloods this week (including iron work, FBC, folate, Vit D and B12), and despite me saying that my B12 level will be high (it's been >2000 since starting monthly injections) they insist on testing it still, and no doubt will tell me that I don't need them so frequently.

I am wondering whether I should try and convince them to test either MMA and / or Homocysteine levels?

Am I right in thinking that even if you have high B12 levels, you can still have a deficiency at the cellular level ("functional B12 deficiency") and that this would be picked up by raised MMA and homocysteine levels?

If this is the case, can anyone point me towards some 'official' documentation which states that, so I can show the Doctors and try to persuade them to do those tests as well?

Thanks for the advice.

[Gambit62 Administrator]

MMA would be the better of the two tests - and MMA would be an indicator of whether you have enough B12 at the cell level.

[jw44 in reply to Gambit62]

Thank you, that is what i thought. Does homocysteine not help as well? Or is that more to do with folate levels?

Do you know of any 'official' documents or guidelines that recommend testing MMA to check B12 deficiency despite high B12 levels that i can show the Dr/midwife to try and convince them to test it?

Many thanks.

[Gambit62 Administrator in reply to jw44]

homocysteine is affected by folate hence the suggestion to use MMA.

onlinelibrary.wiley.com/doi...

Recommendation 6 under cobalamin deficiency. Not entirely relevant but ...

6.Plasma tHcy and/or plasma MMA, depending on availability, may be considered as supplementary tests to determine biochemical cobalamin deficiency in the presence of clinical suspicion of deficiency but an indeterminate serum cobalamin level (Grade 2B).

Although plasma tHcy is a sensitive marker of cobalamin deficiency, plasma MMA is more specific.

Both assays have to be interpreted in relation to renal function.

[jw44 in reply to Gambit62]

Thank you