Posted January 28, 2007
Here is a link to a university paper on Vitamin D and Milk in the US. vitamind.ucr.edu/milk.html
It gets only a little technical so it can still be understood by us laymen.
It seems to answer devotees questions about Vitamin D3 in milk,
although it's not clear if we'll ever know for sure which source (synthetic
or animal) of vitamin D3 is used by any given milk company.