Vitamin D deficiency during late pregnancy mediates placenta-associated complications

Perinatal depression and sun safety behaviors: Results of a pilot intervention trial

Objective: To examine changes in perinatal sun safety behavior and co-occurring minor depression in a pilot intervention trial. Methods: Pregnant women (N = 58) in a sun safety program completed baseline and depression symptom surveys during their second or third trimesters. They then underwent two 30-min sun safety counseling sessions. Follow-up surveys were completed one- and two-months postpartum. Differences in pre- and postpartum sun safety and depression were evaluated. Results: At baseline, participants' mean sun safety score was 23.2/32 (SD = 4.4): 34.5 % were identified as likely depressed and had lower sun safety (t = 1.8, df = 56, p < .05). The mean sun safety score rose to 26.5 at the first follow-up (t = 5.8, df = 57, p < .001) and 26.9 (t = 5.7, df = 57, p < .001) at the second. Participants who were likely depressed at baseline experienced less improvement in sun safety at the first and second follow-ups (t = 3.1, df = 19, p < .01, Cohen's d = 4.3; t = 2.8, df = 19, p < .01, Cohen's d = 4.1, respectively) than those not depressed (t = 4.9, df = 37, p < .001, Cohen's d = 4.3; t = 5.0, df = 37, p < .001, Cohen's d = 5.4, respectively). In an income-adjusted regression model of sun safety at the second follow-up, baseline sun safety remained associated (B = 0.5, SE B = 0.1, p = .001) but not depression (B = -0.4, SE B = 0.2, p = .09). Conclusions: The counseling program increased sun safety adherence, regardless of depression risk.

The role of vitamin D deficiency in placental dysfunction: A systematic review

Introduction

Vitamin D plays a critical role in pregnancy, supporting placental function via angiogenesis, immune regulation, and nutrient transport. Deficiency in vitamin D during gestation is associated with complications such as preeclampsia, intrauterine growth restriction (IUGR), and preterm birth. However, the mechanisms linking vitamin D deficiency to placental dysfunction remain inadequately understood, highlighting the need for systematic evaluation.

Methods

A systematic review was conducted in adherence to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with searches in PubMed, Scopus, and Web of Science for studies published within the last 20 years. Inclusion criteria targeted human studies examining the association between vitamin D and placental function, including randomized controlled trials, cohort studies, and case-control studies. A total of 10 studies were included following rigorous screening and quality assessment.

Results

Findings from human studies indicate that maternal vitamin D deficiency significantly impairs placental function by reducing vascular integrity, downregulating nutrient transporters, and promoting inflammation. Mechanistic evidence highlights decreased expression of vascular endothelial growth factor (VEGF) and increased inflammatory cytokines in vitamin D-deficient pregnancies. Supplementation with active vitamin D [1α,25(OH)2D3] mitigated these adverse effects, restoring placental growth, improving nutrient transport, and reducing inflammation. Notably, population-specific differences and sex-specific responses to vitamin D sufficiency were observed.

Conclusions

Vitamin D is essential for optimal placental function and pregnancy outcomes. This review underscores the need for standardized supplementation protocols and further research into long-term and population-specific effects of vitamin D. Addressing these gaps can inform targeted interventions to reduce pregnancy complications and improve maternal-fetal health.

1,25-Dihydroxyvitamin D3 protects against placental inflammation by suppressing NLRP3-mediated IL-1β production via Nrf2 signaling pathway in preeclampsia

BACKGROUND

Maternal vitamin D deficiency is associated with an increased risk of preeclampsia, a potentially life-threatening multi-system disorder specific to human pregnancy. Placental trophoblast dysfunction is a key factor in the development of preeclampsia, and the activation of NOD-like receptor protein 3 (NLRP3) inflammasome may play a crucial role in this process. Previous studies have suggested that vitamin D can exert beneficial effects by suppressing inflammasome activation, but the underlying mechanism has not been fully elucidated. This study aims to explore the protective effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on the placenta and to investigate the mechanisms by which 1,25(OH)2D3 attenuates NLRP3 inflammasome activation in a rat model of preeclampsia and hypoxia-cultured placental trophoblast cells.

RESULTS

Our findings demonstrated that supplementation of rats with 1,25(OH)2D3 mitigated placental inflammation and prevented multi-organ dysfunction associated with preeclampsia. Treatment with 1,25(OH)2D3 inhibited inflammasome-mediated inflammation in trophoblast cells via its receptor VDR by reducing the expression of NLRP3, caspase-1, and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), decreasing IL-1β production, reducing mitochondrial reactive oxygen species generation, and enhancing the expression and enzymatic activity of Cu/Zn-superoxide dismutase (SOD). Mechanistically, 1,25(OH)2D3 upregulated nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, subsequently suppressing NLRP3-mediated IL-1β overproduction in trophoblast cells.

CONCLUSIONS

Our study indicates that 1,25(OH)2D3 inhibits NLRP3-mediated inflammation in trophoblast cells during preeclampsia by stimulating the Nrf2 signaling pathway and inhibiting oxidative stress.

Effects of High-Dose Vitamin D Supplementation on Placental Vitamin D Metabolism and Neonatal Vitamin D Status

Vitamin D (vitD) deficiency (25-hydroxy-vitamin D < 50 nmol/L) is common in pregnancy and associated with an increased risk of adverse pregnancy outcomes. High-dose vitD supplementation is suggested to improve pregnancy health, but there is limited knowledge about the effects on placental vitD transport and metabolism and the vitD status of newborns. Comparing the current standard maternal supplementation, 10 µg/day to a 90 µg vitD supplement, we investigated placental gene expression, maternal vitD transport and neonatal vitD status. Biological material was obtained from pregnant women randomized to 10 µg or 90 µg vitD supplements from week 11-16 onwards. Possible associations between maternal exposure, neonatal vitD status and placental expression of the vitD receptor (VDR), the transporters (Cubilin, CUBN and Megalin, LRP2) and the vitD-activating and -degrading enzymes (CYP24A1, CYP27B1) were investigated. Maternal vitD-binding protein (VDBP) was determined before and after supplementation. Overall, 51% of neonates in the 10 µg vitD group were vitD-deficient in contrast to 11% in the 90 µg group. High-dose vitD supplementation did not significantly affect VDBP or placental gene expression. However, the descriptive analyses indicate that maternal obesity may lead to the differential expression of CUBN, CYP24A1 and CYP27B1 and a changed VDBP response. High-dose vitD improves neonatal vitD status without affecting placental vitD regulation.

High-Dose Vitamin D Supplementation Significantly Affects the Placental Transcriptome

Vitamin D deficiency is a highly prevalent obstetrical concern associated with an increased risk of complications like pre-eclampsia, gestational diabetes, and growth retardation. Vitamin D status in pregnancy is also linked to long-term offspring health, e.g., the risk of obesity, metabolic disease, and neurodevelopmental problems. Despite the suspected role of vitamin D in placental diseases and fetal development, there is limited knowledge on the effect of vitamin D on placental function. Thus, we performed next-generation RNA sequencing, comparing the placental transcriptome from uncomplicated term pregnancies receiving the often-recommended dose of 10 µg vitamin D/day (n = 36) with pregnancies receiving 90 µg/day (n = 34) from late first trimester to delivery. Maternal vitamin D status in the first trimester was also considered. We found that signaling pathways related to cell adhesion, immune function, and neurodevelopment were affected, supporting that increased vitamin D supplementation benefits placental function in established pregnancies without severe vitamin D deficiency, also underlining the importance of vitamin D in brain development. Specific effects of the first trimester vitamin D status and offspring sex were also identified. Further studies are warranted, addressing the optimal vitamin status during pregnancy with a focus on organ-specific vitamin D needs in individual pregnancies.

Vitamin D Deficiency as a Risk Factor of Preeclampsia during Pregnancy

A balanced diet is achieved not only via the consumption of a variety of food products but also by ensuring that we take in sufficient quantities the micronutrients necessary for the adequate functioning of the human body, such as vitamins, an important one of which is vitamin D. Vitamin D has been closely linked to bone health. Vitamin D deficiency has often been associated with negative effects concerning several pregnancy adverse outcomes, the most important of which are the birth of SGA newborns, premature birth, and, finally, preeclampsia, which are discussed in this work. The aim of this review is to critically summarize and scrutinize whether the concentration of vitamin D in the blood serum of pregnant women in all its forms may be correlated with the risk of preeclampsia during pregnancy and whether vitamin D levels could act both as a protective agent or as a risk factor or even a prognostic measure of the disease. The association of vitamin D levels with the onset of preeclampsia was examined by searching the PubMed and Google Scholar databases. A total of 31 clinical trials were identified and included in this review, with the aim of summarizing the recent data concerning vitamin D levels and the risk of preeclampsia. Among them, 16 were published in the last five years, and 13 were published within the last a decade. Most studies showed a significant association between vitamin D deficiency and preeclampsia risk. It was also found that the higher the dose, the lower the risk of disease. Of the 31 articles, only 7 of them did not show a significant difference between vitamin D levels and preeclampsia regardless of comorbidity. The results of this review suggest that there is indeed an association between the concentration of vitamin D during pregnancy and the risk of preeclampsia; however, further studies are strongly recommended to derive conclusive evidence.

New Ideas for the Prevention and Treatment of Preeclampsia and Their Molecular Inspirations

Preeclampsia (PE) is a pregnancy-specific disorder affecting 4-10% of all expectant women. It greatly increases the risk of maternal and foetal death. Although the main symptoms generally appear after week 20 of gestation, scientific studies indicate that the mechanism underpinning PE is initiated at the beginning of gestation. It is known that the pathomechanism of preeclampsia is strongly related to inflammation and oxidative stress, which influence placentation and provoke endothelial dysfunction in the mother. However, as of yet, no "key players" regulating all these processes have been discovered. This might be why current therapeutic strategies intended for prevention or treatment are not fully effective, and the only effective method to stop the disease is the premature induction of delivery, mostly by caesarean section. Therefore, there is a need for further research into new pharmacological strategies for the treatment and prevention of preeclampsia. This review presents new preventive methods and therapies for PE not yet recommended by obstetrical and gynaecological societies. As many of these therapies are in preclinical studies or under evaluation in clinical trials, this paper reports the molecular targets of the tested agents or methods.

Association of maternal vitamin D status with the risk of preeclampsia

The aim of this study was to examine serum vitamin D concentrations from early pregnancy until delivery in women who did and did not develop preeclampsia. This longitudinal study was carried out in Pune, India. A total of 1154 women with singleton pregnancies were recruited in early pregnancy from two hospitals. Blood samples were collected and stored at four time points across gestation: V1 = 11-14 weeks, V2 = 18-22 weeks, V3 = 26-28 weeks and V4 = at delivery. 108 women who developed preeclampsia (PE) and 216 who did not develop PE (Non-PE) were randomly selected from the remainder. Serum 25-hydroxy vitamin D concentrations (25(OH)D) were estimated in their samples using commercially available ELISA kits. Independent t-tests were used to compare 25(OH)D between PE and non-PE groups. Logistic and linear regressions were used to examine associations of 25(OH)D with the risk of preeclampsia and birth outcomes, respectively, after adjusting for confounders. The mean (SD) 25(OH)D at V1 was 21.95 (19.64) in the Non-PE group and 17.76 (13.21) in the PE group. A decrease in the concentrations of vitamin D (ng ml-1) in mid-pregnancy (V2) and at delivery was associated with an increased risk of preeclampsia (0.31 [95% CI 0.11, 0.86], p = 0.024 and 0.24 [95% CI 0.08, 0.77], p = 0.016), respectively. Our finding of lower vitamin D concentrations in mid-pregnancy, before women developed clinical preeclampsia, suggests that vitamin D may have a role in its pathophysiology.

Dietary supplements and vascular function in hypertensive disorders of pregnancy

Hypertensive disorders of pregnancy are complications that can lead to maternal and infant mortality and morbidity. Hypertensive disorders of pregnancy are generally defined as hypertension and may be accompanied by other end organ damages including proteinuria, maternal organ disturbances including renal insufficiency, neurological complications, thrombocytopenia, impaired liver function, or uteroplacental dysfunction such as fetal growth restriction and stillbirth. Although the causes of these hypertensive disorders of pregnancy are multifactorial and elusive, they seem to share some common vascular-related mechanisms, including diseased spiral arteries, placental ischemia, and endothelial dysfunction. Recently, preeclampsia is being considered as a vascular disorder. Unfortunately, due to the complex etiology of preeclampsia and safety concerns on drug usage during pregnancy, there is still no effective pharmacological treatments available for preeclampsia yet. An emerging area of interest in this research field is the potential beneficial effects of dietary intervention on reducing the risk of preeclampsia. Recent studies have been focused on the association between deficiencies or excesses of some nutrients and complications during pregnancy, fetal growth and development, and later risk of cardiovascular and metabolic diseases in the offspring. In this review, we discuss the involvement of placental vascular dysfunction in preeclampsia. We summarize the current understanding of the association between abnormal placentation and preeclampsia in a vascular perspective. Finally, we evaluate several studied dietary supplementations to prevent and reduce the risk of preeclampsia, targeting placental vascular development and function, leading to improved pregnancy and postnatal outcomes.

The Influence of Maternal Vitamin D Supplementation in Pregnancies Associated with Preeclampsia: A Case-Control Study

Preeclampsia is a pregnancy-specific illness that is hypothesized to occur due to vitamin D deficiency during pregnancy. Therefore, vitamin D supplementation in early pregnancy should be explored for preventing preeclampsia and promoting neonatal well-being. The present study follows a case-control analysis that aims to determine the effect of vitamin D supplements on reducing the probability of recurrent preeclampsia. We identified 59 patients for the control group without vitamin D supplementation during pregnancy, while 139 patients were included in the cases group of pregnant women with a history of preeclampsia who confirmed taking daily vitamin D supplements in either 2000 UI or 4000 UI until the 36th week of pregnancy. There were 61 (80.3%) patients with a normal serum vitamin D level measured at 32 weeks in the pregnant women who took a daily dose of 4000 UI vitamin D and 43 (68.3%) in those who took a 2000 UI dose of vitamin D, compared to just 32 (54.2%) in those who did not take vitamin D at all. Regarding the blood pressure of pregnant women measured at 32 weeks, it was observed that 20.3% were hypertensive in the no supplementation group, compared to only 11.1% and 6.6% in those who were taking vitamin D during pregnancy (p-value = 0.049). Serum vitamin D levels at 32 weeks were measured at an average value of 23.9 ng/mL, compared with 28.4 ng/mL in the group taking a 2000 UI daily dose and 33.6 in those who supplemented with 4000 UI daily (p-value < 0.001). Proteinuria was identified more often in the group at risk for preeclampsia who did not take vitamin D supplements, while systolic blood pressure (p-value = 0.036) as well as diastolic blood pressure (p-value = 0.012), were all identified to have significantly higher values in the pregnant women with a history of preeclampsia that did not take vitamin D during the current pregnancy. The significant risk factors for preeclampsia development in pregnant patients at risk are: insufficient vitamin D serum levels (<20 ng/mL), OR = 2.52; no vitamin D supplementation, OR = 1.46; more than two pregnancies, OR = 1.89; gestational diabetes mellitus, OR = 1.66; and cardiovascular comorbidities, OR = 2.18. These findings imply that vitamin D has a role in the preservation of placental function and, therefore, in the prevention of the development of late preeclampsia. Pregnant mothers who supplemented their diets with vitamin D were protected against preeclampsia recurrence. Vitamin D supplementation during pregnancy may aid in the prevention of gestational hypertension and preeclampsia.

Effects of Vitamin D on Fertility, Pregnancy and Polycystic Ovary Syndrome-A Review

Polycystic ovary syndrome (PCOS) is one of the most common endocrine reproductive disorders in women. Vitamin D deficiency is also quite common in this condition. The degree of vitamin D deficiency correlates with the severity of PCOS. Both male and female vitamin D levels play a role in fertility and affect the outcomes of in vitro fertilization (IVF). Moreover, fertility and IVF indicators are improved by vitamin D not only in healthy women but in those diagnosed with PCOS. Both vitamin D deficiency and PCOS increase pregnancy-related complications. Vitamin D supplementation and optimal vitamin D levels decrease both maternal and fetal risk for complications and adverse events. Furthermore, vitamin D supplementation may ameliorate or even prevent pregnancy-related reversible bone loss in mothers. This review emphasizes the roles of vitamin D deficiency and vitamin D supplementation and their correlation with PCOS regarding reproductive health.