各种原因引起的吸收功能障碍,均可导致某些营养物质特别是B族维生素的缺乏,诱发神经系统疾病,致使周围神经、脊髓或脑细胞的损害变性,从而出现一系列临床症状和体征。 1 维生素B_(12)缺乏小肠远端能选择性吸收维生素B_(12),其吸收依赖于亮氨酸合成酶,因此亮氨酸合成酶缺乏可引起维生素B_(12)吸收障碍。当维生素B_(12)不能与内因子结合,或 A variety of causes of dysfunction caused by absorption, can lead to the lack of certain nutrients, especially B vitamins, induce nervous system diseases, resulting in peripheral nerve, spinal cord or brain cell damage degeneration, resulting in a series of clinical symptoms and signs. The lack of vitamin B_ (12) can selectively absorb vitamin B_ (12) from the distal intestine and its absorption is dependent on leucine synthase. Therefore, the deficiency of leucine synthase can cause the absorption of vitamin B_ (12). When vitamin B_ (12) can not be combined with internal factors, or