人体需要的维生素B12的量很少,使用过量可能引起过敏反应,甚至过敏性休克;摄取不足则可能引起恶性贫血,精神不振等。人类的维生素B12来源于动物性食物如肉类、鱼、贝类、禽蛋和乳类等,植物类食物中不含维生素B12。为补充人体所需要的维生素B12,目前许多保健食品添加维生素B12。为了规范保健食品中维生 The body needs a small amount of vitamin B12, excessive use may cause allergic reactions, or even anaphylactic shock; inadequate intake may cause pernicious anemia, lack of energy and so on. Human vitamin B12 comes from animal foods such as meat, fish, shellfish, eggs and milk, etc., and plant foods do not contain vitamin B12. To supplement the body needs vitamin B12, many health foods currently add vitamin B12. In order to regulate the health food in the subsistence