Not really.... The studies were done up to 1mg a day...orally.

The max absorption from that was 13mcg measured. It is thought that increasing the dose is only going to lead to minor improvements. The author suggested a "ceiling" absorption factor because of how this graph worked out. Maybe 5mg would yield up to 20mcg is my guess.

Here is the table showing:
http://www.ncbi.nlm.nih.gov/pmc/arti...able/T1/#TF1-4
you might have to go there more than once...as PubMed is a bit touchy to link to today.

We are talking minute here....very tiny amounts of a difficult to absorb molecule. The studies on drugs in microgram quantities also show food impairs them. Hence thyroid and digoxin medications get a pharmacy sticker now, to take on an empty stomach.

You just have to accept the science on this. We are lucky someone did this study so that we can understand it better. Instead of people taking B12 and failing because of the food factor, when in fact it can work orally saving you the invasive and more expensive injections.