Goodman K I, Salt W B
Ohio State University College of Medicine.
Postgrad Med. 1990 Sep 1;88(3):147-50, 153-8. doi: 10.1080/00325481.1990.11704733.
Vitamin B12 deficiency develops over a slowly progressive continuum. Early manifestations may be generalized weakness or fatigue, indigestion, diarrhea, or depression. Pernicious anemia is considered the classic cause, but others include malabsorption because of achlorhydria or other gastric dysfunction, fish tapeworm infection, and strict vegetarianism. Iron deficiency often coexists. Because presentation is often atypical, vitamin B12 deficiency is a diagnostic consideration whenever neuropsychiatric signs or symptoms are unexplained.
维生素B12缺乏症是在一个缓慢进展的连续过程中发展起来的。早期表现可能是全身无力或疲劳、消化不良、腹泻或抑郁。恶性贫血被认为是典型病因，但其他病因包括由于胃酸缺乏或其他胃功能障碍引起的吸收不良、鱼绦虫感染和严格的素食主义。缺铁常常并存。由于临床表现往往不典型，每当出现无法解释的神经精神体征或症状时，都应考虑维生素B12缺乏症的诊断。
