onset of mania by vitamin b12 injection in a 52-year old patient with refractory and resistant depression

Vitamin b12 affects and modify the function of multiple organ systems. its deficiency may cause psychiatric symptoms in addition to hematologic, gastrointestinal, and neurologic manifestations. the present case study aims to report  a patient with vitamin b12 deficiency who coexisted with resistant and persistent depression, and experienced mania phase after the replacement of vitamin b12. for a patient with refractory and resistant depression  and evidence or a risk factor for vitamin b12 deficiency, it is required to check plasma levels and monitor psychiatric symptoms during vitamin b12 supplementation. there are some manifestations of b12 deficiency including bipolar disorder, mood lability, irritability, and psychosis due to deficiency but  we  didn’t  find  case  report   about  induce  of  psychiatric  presentation follow   correction  of  vitamin b12  deficiency