How long after injections are MMA and Homocysteine tests inaccurate?

[nikaoo]

I'm having a very hard time finding the answer to this, how long must I go without injections for an MMA or homocysteine test to be accurate? I've read don't supplement before an MMA test but for how long?

Background: I just want to know if there's any chance I've invalidated my test results through prior supplementation enough that PA is still a possibility or if I need to figure out what else this could be.

About 4-6 weeks after last B12 injection my labs were:

B12: >2000 pg/mL (normal range 232-1245) (not a surprise since I've had 4-5 injections within last two months and any supplementation within last 3-4 months will invalidate results)

Intrinsic Factor, Absolute: 1 AU/mL (normal range 0-1.1) (this test shouldn't be invalidated because my understanding is you only need to abstain from injections for about 1 week prior, however false negatives are notoriously common because IF antibodies aren't always the cause)

MMA serum: 81 mmol/L (normal range 0-378)

Homocysteine: 7.1 umol/L (normal range 5-15)

I am on medication for mild hypothyroid and my ferritin has come back normal.

I know it's looking like I don't have PA but my heart palpitations are getting so bad I can't sleep at night and shortness of breath is coming back and when that has happened before B12 injections always made the problem go away right away. I've also been extremely weak over the last few months and other random symptoms that I think are indicative of PA (cold sores, raw mouth, dizziness, lightheaded when standing, seborrheic dermatitis, get bit by bugs a lot). Made the mistake of getting injections before getting tested because symptoms were getting really bad and a hold up with my military insurance prevented me from scheduling an appointment for a while.

Thank you all!

[fbirder]

The tests are never inaccurate. They always give a true representation as to your blood levels of MMA or hCys.

You do not have a B12 deficiency - because you are receiving injections. That means you do not have raised MMA or hCys caused by a B12 deficiency.

If you want to know if you have a B12 deficiency then you could go without any supplements for about 6 months, then have B12, MMA and hCys taken.

Or you could see if B12 injections make your symptoms go away. If they do then you probably have a deficiency. Keep taking the injections. If you don't have a deficiency, but the injections still make the symptoms go away then it must be a placebo effect - keep taking the injections. Who cares how they work if they work?