Answer:
Iron.
Step-by-step explanation:
The individual should take the proper balanced and nutrition dirt for the proper growth and development of an individual. This also reduces the chances of disease in an individual.
Milk is a good source of almost all the nutrients and proteins. But if Alexandra consume all protein from the milk she might have deficiency of the iron in her body. The milk do not contain or contain small amount of iron and dependency only on milk causes iron deficiency in the body.
Thus, the answer is iron.