Periparturient hypocalcemia can be mitigated by reducing prepartum dietary DCAD; however, neither the extent of DCAD adjustment nor the level of dietary Ca fed with negative DCAD have been evaluated fully. This project aimed to compare the effects of two levels of prepartum dietary anion supplementation (urinary pH), two levels of dietary calcium, and the interactions, on parameters of calcium metabolism, health, and milk performance of transition dairy cows.