We’ll defer to our friends at the Canadian Food Inspection Agency (CFIA) to answer your questions. The CFIA regulates this process as it is a legal requirement of the Food and Drug Act.
How is vitamin D added to milk?
“Vitamin Premix is a vitamin preparation supplied to a commercial processor, to be used in the fortification of fluid milk, instant milk powder and evaporated milk products as supplied or as a part of a vitamin solution. Vitamin premixes are available as liquid concentrates, powders or beads.”
When is vitamin D added to milk?
“Vitamin addition can be accomplished at different points in the processing system. These range from addition to the batch pasteurizer, to the high temperature short time (HTST) pasteurizer balance tank, by a batch method to a blender of finished powder prior to final packaging or on a continuous flow method, to finished powder prior to final sifting.”
For a lot more information on vitamins and milk, check out the CFIA’s webpage on this topic.