Whether or not the B complex would provide enough B12 to make a difference for you would depend on how severe your malabsorption is.

If it is severe, the B complex would not provide a bit of B12 (unless it is a very unusual B complex with many many times more than is in most).

However, if you malabsorb from food but can still absorb vitamins normally, there would be enough B12 to get through for you, and some people do show a response to treatment within a few days.

Yes, worsened symptoms can result from repairs.

If I were you, I would also take at least 1000 mcg B12 each day (not timed or extended release), just in case you are headed toward severe malabsorption. That happens to many, so the lower dose is not suggested by medical people who know anything about B12 malabsorption.

Best wishes,

rose