Kuo SC, Yeh CB, Yeh YW, Tzeng NS. (2009) Gen Hosp Psychiatry. 31(6) 586-8. Epub 2009 Mar 27.
Although cobalamin deficiency is widely known and usually presents with hematologic and neuropsychiatric manifestations, the psychiatric symptoms are not usually the predominant manifestation. We describe a young single male vegetarian who developed a cobalamin-induced psychotic episode without preceding neurologic manifestations and without any hematologic symptoms. He recovered after a short course of antipsychotics and oral cobalamin supplementation and remained asymptomatic and functionally independent at 1 year of follow-up.