fatigue, itchy skin, excessive thirst
, high heart rate, nausea, frequent urination
, loose, frequent
bowel movements (can be alternating constipation and diarrhea), low grade fevers.
I would personally recommend sublingual B12 spray. I use this daily for my autoimmune pernicious anaemia. Your B12 issues are not low enough for dementia and nerve damage yet but over time they will be if malabsorption is not corrected.