MMA is it affected by injecting?

[Wattie88]

Hi will MMA indicate pernicious anaemia if you have been injecting b12? Is it linked? I take ad hoc for ME and Pots. My serum and active have previously been in range but b12 did make me feel better I have adeno. My folate is usually low. Haven't got through nhs so only limited supply. Would I need Hommocystein ckeck as well to find a deficiency? I get so confused. I have numbness in toes at times, wobbly walking, pale, neuropathy right side, memory isdues, breathless and cough. These all overlap with ME and Pots though too.

Result MMA urine 3.5 (range 0-2.2 ug/mg)

[AmbersMom]

Sufficient B12 should bring both MMA and HCY into "normal" range unless there are other factors contributing to those numbers. As for serum B12, mine was right in the middle of normal for very many years so no one suspected PA until a savvy practitioner decided to test MMA and HCY levels and parietal cell antibodies due to my antibodies to myelin basic protein. All tests indicated elevated levels so then we knew that PA was an issue.

"An elevated MMA is a very sensitive and specific marker of B12 deficiency. There is evidence that up to 10% of individuals who have normal or low normal B12 values (between 150 and 400 pg/mL) may develop neuropsychiatric sequelae of B12 deficiency without any evidence of megaloblastic anemia. The MMA test can identify this population of functionally B12-deficient individuals. In these patients, oral cyanocobalamin 1-2 mg/day will normalize the MMA and hopefully improve their symptoms. MMA levels can be falsely elevated in renal insufficiency and hypovolemia, in which case levels do not correct with vitamin B12 repletion.

—Susan Kashaf, MD, MPH (123-3)

From the January 05, 2009 Issue of Clinical Advisor"

[Wattie88 in reply to AmbersMom]

Wow thanks for reply. I may have an issue then with raised. I will look in to further. Be good to gert a result and somewhere. X

[Cherylclaire Forum Support]

Raised methylmalonic acid (MMA) can be used as a second indicator of B12 deficiency (after serum B12)- if a second indicator is required. It can't tell whether the B12 is due to PA or not.

In my case it was used to find out if there was a reason for my lack of response to B12 injections when found to be B12 deficient. My GP suspected that I had functional B12 deficiency, which diagnosis was made on raised MMA test result and confirmed by the laboratory. My (non-science) understanding is that B12 links to MMA somewhere in the process, so if you are short of B12, the MMA will begin to build up in bloodstream. Usually, once B12 is replete (reason for loading injections)- the MMA will be able to link up and clear, so rapidly drops back within range.

There are some problems with this:

- The top end of range seems to vary significantly between laboratories with no real consensus (my lab test results had range listed as 0-280 nmol/L)

- There are other causes of raised MMA: renal problems (can be ruled out by blood test for liver and kidney function) and small intestine bacterial overgrowth or SIBO (needs a lengthy fasting hydrogen breath test)

I have only ever had blood tests for MMA (not urine tests). My homocysteine level was tested and found to be normal. My Intrinsic Factor antibody test (IFab) was negative, my gastric parietal antibody test was negative too.

MMA wasn't tested before B12 injections were started, so I have no idea how high it was then. It was never considered "high" just "raised", remained raised long after B12 injections started (always between 350-400 nmol/L) and in fact took 3 years to drop down to within range.

By then, my MMA had been tested six times. The first time was -with some difficulty- by GP request, the next four by haematology consultants, the final test last year (205 nmol/L) by Inherited Metabolics consultants, who found no cause for these problems in my DNA.

It also took about 2 years for my ferritin and folate levels to improve and stabilise, and I'm having a Dexascan this week to see if my bone density has improved, as I have osteoporosis of the spine. Most of my B12 deficiency symptoms are now less frequent, less severe, some are rare.

It must be very difficult for you to disentangle symptoms. Your MMA is raised and this is worth investigating further. Hope this helps you.