牛奶是人们最容易获得的钙来源。然而,事实上,如果按照营养素密度来计算,牛奶的补钙效益低于青菜。按照数据计算,1 00克全脂牛奶能量约为54千卡,含钙1 04毫克。而100克小油菜含能量约为15千卡,含钙却高达153毫克。那么,按照钙营养素密度来计算,全脂牛奶为104/54=1,9,而小油菜是 Milk is the most readily available source of calcium for people. However, in fact, the milk’s calcium supplement is lower than that of greens if calculated on nutrient density. In accordance with the data, 1 00 grams of whole milk energy is about 54 kcal, calcium 104 mg. 100 grams of small rape contains energy is about 15 kcal, calcium is as high as 153 mg. Well, in terms of calcium nutrient density, the whole milk is 104/54 = 1, 9, while the small rape is