科学研究表明,素食中绝无维生素B_(12);因此,长期过度的素食,可引起维生素B_(12)的严重缺乏。而维生素B_(12)是细胞核酸和蛋白合成代谢过程所必需的物质,因为它有促进红细胞成熟和血红蛋白合成的作用。缺少它就会产生恶性贫血。维生素B_(12)还是神经营养剂,对神经机能有促进和保护作用,缺 Scientific research shows that there is absolutely no vitamin B 12 in vegetarian diet; therefore, long-term excessive vegetarian diet can cause a serious deficiency of vitamin B 12. Vitamin B_ (12) is a necessary substance in the process of anabolic metabolism of nucleic acids and proteins because of its role in promoting red blood cell maturation and hemoglobin synthesis. Lack of it will produce pernicious anemia. Vitamin B_ (12) or neurotrophic agents, have a role in promoting and protecting the nervous function, lack