Galactosemia is a disorder that is treated by restricting milk.
Step-by-step explanation:
The lactose sugar present in the milk is made up of simpler subunit galactose and glucose. In some individuals, the enzyme galactase-1-phosphate uridyl transferase is not present or not working properly. This enzyme is required to convert galactose into glucose. As a result of this dysfunctional enzyme large amount of galactose is present in the blood. In such cases, milk is avoided.