Cow's milk can produce iron deficiency by providing little dietary iron itself, and at the same time producing ironloss 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。
2
Exercise can result in ironloss through a variety of mechanisms.