The way intrinsic factor works is to take the 1 or 2 micrograms broken out of protein from animal sources. It is such a minute amount the intrinsic factor complexes the B12 and holds it so it cannot get lost in the GI tract amongst the food there.
When you take oral supplements there is a huge dose present
(sometimes more that 1000x that of food) so if the food is not present in the GI tract at that time, the B12 is able to passively pass thru the GI membranes and get into the blood.
If transcobalamin is working there, it snaps up the B12 and carries it around in the blood until releasing it in tissues.
It is known now that the mouth membranes are too small to get much B12 into the blood that way; B12 is a huge molecule and chemically can't get thru well that way.
The link to the table I gave you here shows that B12 can orally work and therefore explains it clearly.
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All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
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Weezie looking at petunias 8.25.2017
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