The effects of a dietarydeficiency cannot be studied in a controlled way.
营养不良症不能在一种控制的状态下进行研究。
2
Cow's milk can produce iron deficiency by providing little dietary iron itself, and at the same time producing iron loss by inducing gastrointestinal bleeding.
牛奶本身缺乏可食用铁，因此可能引起缺铁，同时可能引发肠胃流血造成铁的流失。
3
The most common nutritional deficiency is lack of dietary iron.