just a thought

[Dougalling]

If I fed B12 to celery, then ate the celery, would that be a better way of ingesting B12 ?

It would be the same liquid B12 but it would be in a plant.

[calvin]

From T Colin on the subject of B12:

What foods might naturally contain B12?
-Animal foods, including meat, milk, and eggs, contain B12 and are essentially the exclusive source of the vitamin in the American food supply (not counting supplements or fortification).
-Two varieties of edible algae (Dried green (Enteromorpha sp.) and purple (Porphyra sp.) seaweed (nori)) have been found to have active B12, but other algae have inactive B12-analog compounds that have no apparent benefit in animal metabolism.
-Some varieties of mushrooms and some foods made with certain fermentation processes have very small amounts of active B12.
-Plants found in our food supply do not contain B12, though plants grown in experimental settings with B12-enriched soils or water (with hydroponic processes, for example) do actually take up B12.

[bbq]

Let's define "better" first, not really sure about that.

We've got 30 trillion human cells and 39 trillion bacteria in each body, ingesting beneficial bacteria wouldn't be such a bad idea.

And then we're really working hard to feed those bacteria plenty of starches since they'll save us from colon cancer etc.

http://nutritionfacts.org/video/getting-starch-to-take-the-path-of-most-resistance/

Now let's look the Cyanocobalamin molecule as well as the Methylcobalamin molecule respectively:

https://pubchem.ncbi.nlm.nih.gov/compound/184933
https://pubchem.ncbi.nlm.nih.gov/compound/4289526
C63H88CoN14O14P

https://pubchem.ncbi.nlm.nih.gov/compound/24892769
https://pubchem.ncbi.nlm.nih.gov/compound/53477746
C63H91CoN13O14P

Both of them are HUGE molecules when compared to simple sugars (C6H12O6) or vitamin C (C6H8O6) so we've gotta figure out how to absorb something like that when it ain't exactly easy to do so:

http://www.doctoryourself.com/nasal.html

Intravenous B12 is best, followed by nasal administration, next in line is sublingual, and the least efficient one should be oral.

Yeah, they've got so much B12 in meat but strong stomach acid must be present to cleave B12 from the meat protein in the first place.

We've gotta consider intrinsic factor, ileal absorption, and also medications that would affect the intake of B12 as mentioned below:

https://books.google.com/books?id=2C2MAwAAQBAJ&pg=PA1322

(Zoom in if the texts linked above were too small, please.)

We've been somewhat "brainwashed" since our childhood to be afraid of bacteria but those little critters really are part of the fabrics of life. Keeping things as sterile as possible and that's exactly why we don't get enough B12 if we weren't taking supplements or eating fortified foods.

[GeoffreyLevens]

Intravenous B12 is best, followed by nasal administration, next in line is sublingual, and the least efficient one should be oral.

I don't think B12 is ever (or at least very seldom) given i.v. Intramuscular or i.m. is the common medical route.
Also

Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency: a systematic review of randomized controlled trials

Conclusions. The evidence derived from these limited studies suggests that 2000 µg doses of oral vitamin B12 daily and 1000 µg doses initially daily and thereafter weekly and then monthly may be as effective as intramuscular administration in obtaining short-term haematological and neurological responses in vitamin B12-deficient patients.