Many milks are fortified with vitamins A and D. Vitamin D is found naturally in very few foods and was initially added to milk, a staple food, to reduce the incidence of rickets, a bone softening condition in children that was at one time endemic in North America.
The fortification of milk and infant milk with 400 IU of vitamin D2 or vitamin D3 has eliminated rickets as a health problem in the United States and Canada.
Because vitamins A and D are fat soluble they are found in the milk fat of whole milk. For this reason, whole milk is not required to be fortified with either vitamin, although many milk manufacturers add both.
Vitamin A and carotene are in the fat portion of the milk, the vitamin A activity is removed in reduced fat (2% fat) and fat free milks, dried whole milk and evaporated skim milk, so vitamin A fortification is required.
The fortification of dried skim milk with vitamin A is viewed by WHO and FAO as an important measure to combat vitamin A deficiency in developing countries.
Fortification with vitamin D in reduced fat and fat free milks is optional. Vitamin D fortification is required for evaporated whole and fat free milks.
Vitamin fortification in milk
