Yes, its safety when used as a food additive has been approved by the U.S. Food and Drug Administration (FDA), European Food Safety Authority (EFSA), Joint FAO/WHO Expert Committee on Food Additives (JECFA), as well as other authorities.
FDA
The FDA has claimed that calcium caseinate can be used for color or coloring adjunct, formulation aid, nutrient supplement, stabilizer or thickener and texturizer in food. (2)
Uses
It can be used in frozen desserts and creamed cottage cheese. (3)
http://www.chinafooding.com/Calcium_Caseinate
PR