Dementia associated with vitamin B(12) deficiency: presentation of two cases and review of the literature.

Vitamin B(12) deficiency has long been associated with a wide variety of hematological, neurological, and psychiatric disorders. The role of vitamin B(12) deficiency as one of the few treatable causes of dementia, however, is still controversial. The authors report on 2 elderly patients suffering from cognitive impairment and psychotic symptomatology probably related to cobalamin deficiency, who showed improvement after parenteral vitamin B(12) substitution. The literature concerning the pathophysiology and the diagnostic and therapeutic aspects of cobalamin deficiency is reviewed.