These signaling cascades play a pivotal role in regulating cellular functions such as proliferation, differentiation, invasion, and apoptosis hence highlighting the modulatory effects of Vitamin D. VDR allelic variants and altered VDR expressions are associated with a number of health concerns including prostate cancer (Ingles et al., 1997), breast cancer (Whitfield et al., 2001), and sarcoidosis (Niimi et al., 1999), but the role of VDR and Vitamin D signaling in pregnancy is poorly understood. Here, VDR is linked to breast cancer.