《英文msh词典》Vitamin B12 Deficiencies
[入口词] Vitamin B12 Deficiencies
[主题词] Vitamin B 12 Deficiency
[英文释义] A nutritional condition produced by a deficiency of VITAMIN B 12 in the diet,characterized by megaloblastic anemia. Since vitamin B 12 is not present in plants,humans have obtained their supply from animal products,from multivitamin supplements in the form of pills,and as additives to food preparations. A wide variety of neuropsychiatric abnormalities is also seen in vitamin B 12 deficiency and appears to be due to an undefined defect involving myelin synthesis. (From Cecil Textbook of Medicine,19th ed,p848)