_applied_  
_sciences_  
_Article_  
**Placental mRNA and Protein Expression of VDR, CYP27B1 and CYP2R1 Genes Related to Vitamin D Metabolism in Preeclamptic Women**  
**[PERSON] 1, [PERSON] 1, [PERSON] 2,*\(\copyright\), [PERSON] 3, [PERSON] 1,4, [PERSON] 1, [PERSON] 5, [PERSON] 6 and [PERSON] 1**  
1 Division of Perinatology and Women's Disease, Poznan University of Medical Sciences, Polna 33, 60-535 Poznan, Poland; [EMAIL_ADDRESS] (J.-M.-S); [EMAIL_ADDRESS] (G.K.); [EMAIL_ADDRESS] (H.W. ); [EMAIL_ADDRESS] (K.D. ); [EMAIL_ADDRESS] (A.S.-M.)  
2 Department of Biotechnology, Institute of Natural Fibres and Medicinal Plants, Wojska Polskiego 7 lb, 60-630 Poznan, Poland  
3 Department of Pharmacology and Phytochemistry, Institute of Natural Fibres and Medicinal Plants, Kolejowa 2, 62-064 Plewiska, Poland; [EMAIL_ADDRESS]  
4 Institute of Medical Sciences, Podhale State College of Applied Sciences, ul. Koksoszkow 71, 34-400 Novey Tag, Poland  
5 Chair and Department of Medical Microbiology, Poznan University of Medical Sciences, Wieniawskiego 3, 61-712 Poznan, Poland; [EMAIL_ADDRESS]  
6 Department for Research on Stem Cells and Regenerative Medicine, Institute of Natural Fibres and Medicinal Plants, Kolejowa 2, 62-064 Plewiska, Poland; [EMAIL_ADDRESS]  
7 Correspondence: [EMAIL_ADDRESS]  
**Citation:** [PERSON] [PERSON]; [PERSON], [PERSON]; [PERSON], [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON] Placental mRNA and Protein Expression of VDR, CYP27B1 and CYP2R1 Genes Related to Vitamin D Metabolism in Preeclamptic Women. _Appl. Sci._**2021**, _11_, 11880. [[https://doi.org/10.3390/appl12411880](https://doi.org/10.3390/appl12411880)]([https://doi.org/10.3390/appl12411880](https://doi.org/10.3390/appl12411880))  
**Publicisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. **Copyright:** 2021 by the authors. License MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/)]([https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/))). **Abstract:** (1) Background: Considerable evidence indicates that the occurrence of preeclampsia (PE) is associated with a reduced vitamin D (VD) level. Several studies have found that VD deficiency is correlated with disturbed trophoblast invasion, reduced angiogenesis and increased vasoconstriction. Because the vitamin D receptor (VDR) and CYP27B1 and CYP2R1 hydrolases are strongly involved in VD metabolism, the goal of the present study was to evaluate their genes and proteins expression in the placentas from preeclamptic women. (2) Methods: Samples and clinical data were obtained from 100 Polish women (41 women with preeclampsia and 59 healthy pregnant controls). The whole PE group was divided into subgroups according to gestation week of pregnancy ending before and after 34 gestational weeks (early/late-onset preeclampsia (EOPE/LOPE)). However, finally, to reduce confounding by differences in gestational age, the EOPE group was excluded from the analysis of mRNA and protein placental expression, and we focus on the expression between LOPE and control groups. The placental VDR, CYP27B1 and CYP2R1 mRNA expression was analyzed using RT-PCR, and placental protein levels were determined by ELISA assay. (3) Results. (3.1) Placental gene expression: Expression levels of both genes, CYP27B1 (1.17 vs. 1.05 in controls, \(p\) = 0.006) and CYP2R1 (2.01 vs. 1.89 in controls, \(p\) = 0.039), were significantly higher in preeclamptic placentas than in the control group. Interestingly, VDR expression was significantly lower in placentas from the PE group (1.15 vs. 1.20 in controls, \(p\) = 0.030).