Sublingual vitamin B12 pills

Why is it that my vitamin B12 pills are taken sublingually? Does it absorb better in the mouth or does the stomach acid destroy it or something like that?

I have used both sublingual B-12 and regular ones, made by the same company and I have to watch carefully to make sure I buy the right bottle. I switched to the sublinguals because, as a gastric pypass patient, I have malabsorption issues with anything taken in pill form, and though I have so far been fine with my B-12 levels, I wanted to use the form that would insure I get the full dose. But you can just as easily buy yours in the regular pill form if you don’t have the “I don’t have a real stomach anymore” issue.

And to be honest, half the time I just swallow them along with my BP meds and my morning Tylenol and don’t wait for them to dissolve under my tongue.