It's not clear to me how the notion arose that calcium salts contain milk
ingredients of any kind, but it's not true, even for calcium lactate.

From my Dairy or Non-Dairy page:
http://ourworld.compuserve.com/homepages/stevecarper/experts.htm

"Note that FAAN (The Food Allergy & Anaphylaxis Network) says of calcium and
sodium lactate: "They do not contain milk protein and need not be restricted
by someone avoiding milk."

Cross-contamination is the most likely problem, rather than any particular
ingredient in the Wendy's Mandarin Chicken Salad.

Steve Carper
Steve Carper's Lactose Intolerance Clearinghouse