A seventy-four years old woman is assessed for asthenia, fatigue, non ulcerous dyspepsia with macrocytic anemia. The patient's medical history taking in Binswanger disease--diagnosed 5 aa before-, epilepsy-2 aa before- and a previous episode of TVP of the left leg, suggested the hypothesis that a B12 deficiency, by a chronic gastritis, would involve an increase of homocysteine cause of the clinical manifestations of megaloblastic anemia, Binswanger disease, tardive epilepsy and previous TVP. The fisic and blood and instrumental exams confirmed the clinical diagnosis. The patient is having vitamin B12.