vitamin D

vitamin-d的词性：
n.（名词）

1. A fat-soluble vitamin occurring in several forms, especially vitamin D₂ or vitamin D ₃, required for normal growth of teeth and bones, and produced in general by ultraviolet irradiation of sterols found in milk, fish, and eggs.
维生素D：以多种形式存在的一种脂溶性维生素，包括维生素D₂或维生素D ₃，为牙齿和骨骼生长所必需，一般通过对牛奶、鱼和蛋中的固醇进行紫外线照射获得