Reversible psychosis associated with vitamin B12 and folate deficiency managed in outpatient care: A case series

Vitamin B 12 and folate deficiency are recognized causes of neuropsychiatric manifestations, though presentation as acute psychosis remains uncommon. Early identification is crucial because psychiatric symptoms may be reversible with appropriate treatment. We describe four female patients presenting to the psychiatry outpatient department with an acute onset of psychosis characterized by delusions and hallucinations, without prior psychiatric illness. All four patients showed hematological evidence of macrocytic anemia with low serum vitamin B 12 (78–91 pg/mL), with three showing concomitant folate deficiency. Neuroimaging was normal in all cases. Patients were managed on an outpatient basis with parenteral vitamin B 12 , oral folic acid, and short-term low-dose antipsychotics. Psychotic symptoms improved within 2–4 weeks and resolved completely within 4–8 weeks following vitamin replacement and short-term antipsychotic therapy. This case series highlights that combined vitamin B 12 and folate deficiency can present as acute psychosis and be safely recognized and managed in an outpatient setting. Routine screening for nutritional deficiencies in first-episode psychosis may prevent unnecessary hospitalization and ensure complete recovery.