Adding heat to raw milk causes mild nutrient loss in pasteurized milk. The University of Minnesota reports that pasteurized milk loses 3 to 4 percent thiamin, less than 5 percent vitamin E and less than 10 percent of biotin during the heating process. Jesse Gregory III demonstrated in 1982 that the denaturation of milk’s whey proteins through pasteurization can decrease how well your body absorbs the milk’s vitamin B12. Ultra-pasteurization may further degrade these nutrients, though the increased shelf life of the milk often offsets the additional nutritional cost.