vitamin K
vitamin-k的词性：
n.（名词）
1. A fat-soluble vitamin, occurring in leafy green vegetables, tomatoes, and egg yolks, that promotes blood clotting and prevents hemorrhaging. It exists in several related forms, such as K1 and K 2.
维生素K：一种脂溶性维生素，主要存在于绿叶蔬菜、西红柿和蛋黄中，可促进凝血并防止出血。它以几种相关形式存在，如K1和K 2