Maternal vitamin D sufficiency and reduced placental gene expression in angiogenic biomarkers related to comorbidities of pregnancy

- Definition of maternal 25(OH)D sufficiency during pregnancy is reviewed.
- Placental changes in vascular disorders of pregnancy are discussed.
- Sufficient 25(OH)D concentrations in relation to placental expression is presented.
- Vitamin D3 supplementation impact on placental gene transcription is highlighted.
- Improving outcomes of suspected vascular disorders of pregnancy is offered.

IntroductionMaternal circulating 25-hydroxyvitamin D [25(OH)D] has been shown to optimize production of 1,25-dihydroxyvitamin D [1,25(OH)2D] during pregnancy at approximately 100 nmoles/L, which has pronounced effects on fetal health outcomes. Additionally, associations are noted between low maternal 25(OH)D concentrations and vascular pregnancy complications, such as preeclampsia. To further elucidate the effects of vitamin D activity in pregnancy, we investigated the role of maternal 25(OH)D, the nutritional indicator of vitamin D status, in relation to placental maintenance and, specifically, expression of placental gene targets related to angiogenesis and vitamin D metabolism.MethodsA focused analysis of placental mRNA expression related to angiogenesis, pregnancy maintenance, and vitamin D metabolism was conducted in placentas from 43 subjects enrolled in a randomized controlled trial supplementing 400 IU or 4400 IU of vitamin D3 per day during pregnancy. Placental mRNA was isolated from biopsies within one hour of delivery, followed by quantitative PCR. We classified pregnant women with circulating concentrations of <100 nmoles/L as deficient and those with ≥100 nmoles/L as sufficient. The value of each gene's change in the PCR cycle threshold (ΔCT), which is a relative measure of target concentration, was compared with maternal 25(OH)D concentrations <100 nmoles/L and ≥100 nmoles/L based on a two-sample Wilcoxon test.ResultsSoluble FMS-like tyrosine kinase 1 (sFlt-1) and vascular endothelial growth factor (VEGF) gene expression was significantly downregulated in the maternal subgroup with circulating 25(OH)D ≥100 ng/mL compared to the subgroup <100 ng/mL.DiscussionHere, we report a significant association between maternal vitamin D status and the expression of sFlt-1 and VEGF at the mRNA level. Achieving maternal circulating 25(OH)D ≥100 nmoles/L suggests the impact of maternal vitamin D3 supplementation on gene transcription in the placenta, thereby potentially decreasing antiangiogenic factors that may contribute to vascular pregnancy complications.