Can B12 deficiency cause abdominal nerve entrapment?

[Hamayeshguy]

My first symptom of B12 deficiency started with weak stomach muscle almost six years ago and ended to severe abdomen muscle weakness and umbilical hernia.

But no GP could find out what's wrong. It's full pain and causes feel constant pressure in abdomen area and in of my worst symptoms which I think most if my continuous sweating even at sleep is due to this problem. When I searched I found in low B12 some nerves can entraped in non detected in muscles inside injury's scar and causes nerve damage directly. But I'm not sure it can happen in other parts of the body? Any recommendation would be appreciated