The amount of B12 in your current vitamins is not high enough to be therapeutic if you have either a DNA mutation (which is common) called the MTHFR polymorphism. This would result in the cyano form in the vitamins not being activated in the body to the active form called methylcobalamin. If you have low stomach acid then intrinsic factor will fail to aid cyanocobalamin absorption as well.

There is a study that measured B12 absorption from oral forms.
http://www.ncbi.nlm.nih.gov/pmc/arti...able/T1/#TF1-4
This study compared injectable and oral for doses up to 1000mcg.

The result is that with oral 1000mcg only 13mcg are actually making it to the blood stream where it is needed.

Without knowing your actual blood test results, it is not possible then to know if you are below the new 400pg/ml cut off. Labs still report very low levels as "normal" and doctors then tell patients they are okay, when in fact they are quite low. Low blood levels then cause low levels in the brain and spinal cord, and with time, there is deterioration in nerve functions throughout the body.

So it would be best to get your actual values from testing. Other countries use another concentration than pg/ml, so you need that part of the numerical result as well, so it can be converted to pg/ml.

This is my B12 thread:
http://neurotalk.psychcentral.com/thread85103.html

Don't fall thru the medical cracks, that exist today for this crucial nutrient.