Goncalves DR, et al. - Researchers explored the link between vitamin D (VD) deficiency [VDD] and recurrent pregnancy loss (RPL) by systematically reviewing data for women with 2 or more spontaneous abortion (SA) included in 11 studies. Given that the effects of VDD in pregnancy have been associated with preeclampsia, gestational diabetes, fetal growth restriction, preterm labor, and sporadic SA. Based on the findings, a beneficial role for VD supplementation in RPL can be speculated. In women with RPL, vitamin D receptor (VDR) and CYP27B1 expression in endometrium did not seem to be different but a decreased expression of VDR and, perhaps, a decreased expression of CYP27B1, appeared in villous and decidual tissues.