People who lack enough stomach acid to break B12 out of food still can absorb from a small amount of supplemental B12.

However, if that person has progressed to lack of intrinsic factor (true pernicious anemia) a very large oral dose is necessary to absorb any.

That is why for either of these types of malabsorption at least 1000 mcg at a time is suggested. Not timed or sustained release.

It is not necessary to take betaine with your B12, but betaine is a very good idea for most who malabsorb B12. Lack of sufficient stomach acid is at the root of an amazing number of things.

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