I recently had my active vitamin B12 tested by Blue Horizon and the results showed it was within the normal range (76 pmol/L). I've read elsewhere on this site that there are recommendations to have an MMA test, if the B12 result is less than 70. I haven't come the MMA test before, so had a little look around on the internet.........even though my result is NOT less than 70, it is quite close and I wanted to see if I would benefit from an MMA test.
Apparently, the MMA test is the ONLY test than can tell if you are B12 deficient or not. Methlymalonic acid (or methylmalonate; MMA) is a waste product that builds up in the blood if B12 is not available. I read that you can have low, normal or high levels of B12 and STILL be deficient, and the MMA test is the only way to find out. Presumably it's a more accurate indicator of B12 deficiency because it's showing whether the metabolic need for B12 is being met by the levels of B12 in the blood..... or something. Not entirely sure, to be honest.
So, I am now thinking that my paying £64 for the B12 test was a waste of money and I should have just gone straight for the MMA test (£324 for blood test or £139 for urine test, both with Medichecks - yet more money!)
I wanted to raise this, in case it helps others when deciding what tests they need. I'd also be interested to hear if anyone knows whether the above is totally correct or not!