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 is Associated With Increased Plasminogen Activator Inhibitor 1/Plasminogen Activator Inhibitor 2 Ratio in Pregnancy.

BACKGROUND: Vitamin D deficiency has recently been suggested as an independent risk factor for thrombosis. Notably, vitamin D deficiency is common in pregnant populations, whom already have an increased thrombotic risk. However, pregnant women are commonly excluded from studies investigating the hemostatic system, and knowledge on the impact of vitamin D on hemostasis in pregnancy is therefore limited. METHODS: A cross-sectional study comparing the hemostatic profile of pregnant women (gestational week 12.9 ± 0.7) with vitamin D deficiency (≤50 nmol/L) (n = 70) and high adequate vitamin D status (≥100 nmol/L) (n = 59). RESULTS: Vitamin D deficient women displayed increased plasminogen activator inhibitor 1 levels and an increased plasminogen activator inhibitor 1/plasminogen activator inhibitor 2 ratio, even after adjusting for factors with potential influence on hemostasis (body mass index, smoking and use of fish oil supplements). CONCLUSIONS: Vitamin D deficiency is associated with increased plasminogen activator inhibitor 1/plasminogen activator inhibitor 2 ratio in pregnant women. As an increased plasminogen activator inhibitor 1/plasminogen activator inhibitor 2 ratio with high plasminogen activator inhibitor 1 levels may increase thrombotic risk and is associated with the development of pregnancy complications, further research is needed to determine the optimal vitamin D supplementation in pregnancy.

Vitamin D in pregnancy (GRAVITD) - a randomised controlled trial identifying associations and mechanisms linking maternal Vitamin D deficiency to placental dysfunction and adverse pregnancy outcomes - study protocol.

BACKGROUND: The prevalence of vitamin D deficiency is high among pregnant women. Vitamin D deficiency in pregnancy is associated with increased risk of adverse pregnancy outcomes especially complications related to placental dysfunction and insulin resistance. The objective of this study is to investigate if a higher dose of vitamin D supplementation in pregnancy reduces the prevalence of vitamin D deficiency and prevents adverse pregnancy outcome with special emphasize on preeclampsia, foetal growth restriction and gestational diabetes. METHODS: GRAVITD is a double-blinded randomised trial with parallel groups where all pregnant women attending the free of charge national nuchal translucency scan programme in gestational week 10-14 at Randers Regional Hospital are invited to participate. Enrolment started in June 2020. Participants are randomised in a two armed randomization with a 1:1 allocation ratio into 1) control group - receives 10 µg of vitamin D or 2) intervention group - receives 90 µg of vitamin D. A total of 2000 pregnant women will be included. Maternal blood samples and questionnaires describing life-style habits are collected upon enrolment. For half of the participants blood samples and questionnaires will be repeated again in 3rd trimester. Blood samples will be analysed for 25-hydroxy-vitamin D using high-performance liquid chromatography coupled with tandem mass spectrometry. Upon delivery, placental tissue and umbilicalcord blood will be collected and information on maternal and fetal outcomes will be exstracted from medical records. The primary outcomes are serum levels of 25-hydroxy-vitamin D ≥ 75 nmol/L and the rate of preeclampsia, foetal growth restriction and gestational diabetes. Secondary outcome includes identification and impact on placental functions related to vitamin D. A tertiary outcome is to initiate a cohort of children born from mothers in the trial for future follow-up of the effects of vitamin D on childhood health. DISCUSSION: Provided that this trial finds beneficial effects of a higher dose of vitamin D supplementation in pregnancies, official recommendations can be adjusted accordingly. This will provide a low-cost and easily implementable adjustment of prenatal care which can improve health for both mother and child during pregnancy and beyond. TRIAL REGISTRATION: ClinicalTrial.gov: NCT04291313 . Registered February 17, 2020.

Vitamin D insufficiency among Danish pregnant women-Prevalence and association with adverse obstetric outcomes and placental vitamin D metabolism.

INTRODUCTION: In pregnancy, vitamin D deficiency is associated with increased risk of fetal growth restriction and preeclampsia. The underlying mechanisms are not known, but placental dysfunction is believed to play a role. In a Danish population, where health authorities recommend a 10 µg/day vitamin D supplement during pregnancy, we explored current use of vitamin D supplements and vitamin D status. In term placentas, alterations in vitamin D metabolism and placental growth, evaluated by the key placental growth factor pregnancy-associated plasma protein-A (PAPP-A), and their relation to vitamin D insufficiency were investigated. MATERIAL AND METHODS: We included 225 randomly selected pregnant women attending a nuchal translucency scan at gestational weeks 11-14. Information on use of vitamin D supplements and body mass index (BMI) at inclusion was obtained using self-reported questionnaires. Plasma 25-hydroxyvitamin D was measured at inclusion and correlated with pregnancy outcomes and placental biology, as judged by expression of PAPP-A and enzymes involved in vitamin D metabolism (CYP24A1, CYP27B1) in term placentas. RESULTS: Vitamin D supplements were used by 92% of the women, but 42% were vitamin D insufficient (plasma 25-hydroxyvitamin D <75 nmol/L). Eleven women with singleton pregnancies developed fetal growth restriction or preeclampsia. In this small subset, first-trimester mean plasma 25-hydroxyvitamin D was lower in women who developed fetal growth restriction (43 ± 33nmol/L; n = 3; P = .006) and there was a tendency towards lower plasma 25-hydroxyvitamin D among women who developed preeclampsia (65 ± 19 nmol/L; n = 8; P = .08) in third trimester compared with uncomplicated pregnancies (79 ± 22 nmol/L; n = 187). In term placentas, PAPP-A expression was lower among participants with first-trimester vitamin D insufficiency (P = .009; n = 30) but no correlation was found between plasma 25-hydroxyvitamin D and mRNA expression of CYP24A1 (P = .67) and CYP27B1 (P = .34). BMI was negatively correlated with plasma 25-hydroxyvitamin D (P = .03) and positively correlated with placental mRNA expression of CYP24A1 (P = .003; n = 30). CONCLUSIONS: Despite high compliance with official guidelines regarding vitamin D supplements, vitamin D insufficiency was frequent and the findings indicate that vitamin D insufficiency may affect placental growth. High BMI was associated with vitamin D insufficiency and increased placental vitamin D turnover, but further investigations are needed.

Reduced hepatic metallothionein expression in first trimester fetuses in response to intrauterine smoking exposure: a consequence of low maternal zinc levels?

STUDY QUESTION: Does maternal smoking in early pregnancy affect metallothionein 1 and 2 (MT1 and MT2) mRNA and protein expression in first trimester placenta or embryonic/fetal liver? SUMMARY ANSWER: In the first trimester, MT protein expression is seen only in liver, where smoking is associated with a significantly reduced expression. WHAT IS KNOWN ALREADY: Zinc homeostasis is altered by smoking. Smoking induces MT in the blood of smokers properly as a result of the cadmium binding capacities of MT. In term placenta MT is present and smoking induces gene and protein expression (MT2 in particular), but the MT presence and response to smoking have never been examined in first trimester placenta or embryonic/fetal tissues. STUDY DESIGN, SIZE, DURATION: Cross sectional study where the presence of MT mRNA and protein was examined at the time of the abortion. The material was collected with informed consent after surgical intervention and frozen immediately. For protein expression analysis, liver tissue originating from smoking exposed n = 10 and unexposed n = 12 pregnancies was used. For mRNA expression analyses, placental tissue originating from smokers n = 19 and non-smokers n = 23 and fetal liver tissue from smoking exposed n = 16 and smoking unexposed pregnancies n = 13, respectively, were used. PARTICIPANTS/MATERIALS, SETTING, METHODS: Tissues were obtained from women who voluntarily and legally chose to terminate their pregnancy between gestational week 6 and 12. Western blot was used to determine the protein expression of MT, and real-time PCR was used to quantify the mRNA expression of MT2A and eight MT1 genes alongside the expression of key placental zinc transporters: zinc transporter protein-1 (ZNT1), Zrt-, Irt-related protein-8 and -14 (ZIP8 and ZIP14). MAIN RESULTS AND THE ROLE OF CHANCE: A significant reduction in the protein expression of MT1/2 in liver tissue (P = 0.023) was found by western blot using antibodies detecting both MT forms. Overall, a similar tendency was observed on the mRNA level although not statistically significant. Protein expression was not present in placenta, but the mRNA regulation suggested a down regulation of MT as well. A suggested mechanism based on the known role of MT in zinc homeostasis could be that the findings reflect reduced levels of easily accessible zinc in the blood of pregnant smokers and hence a reduced MT response in smoking exposed fetal/embryonic tissues. LIMITATIONS AND REASONS FOR CAUTION: Smoking was based on self-reports; however, our previous studies have shown high consistency regarding cotinine residues and smoking status. Passive smoking could interfere but was found mainly among smokers. The number of fetuses was limited, and other factors such as medication and alcohol might affect the findings. Information on alcohol was not consistently obtained, and we cannot exclude that it was more readily obtained from non-users. In the study, alcohol consumption was reported by a limited number (less than 1 out of 5) of women but with more smokers consuming alcohol. However, the alcohol consumption reported was typically limited to one or few times low doses. The interaction between alcohol and smoking is discussed in the paper. Notably we would have liked to measure zinc status to test our hypothesis, but maternal blood samples were not available. WIDER IMPLICATIONS OF THE FINDINGS: Zinc deficiency-in particular severe zinc deficiency-can affect pregnancy outcome and growth. Our findings indicate that zinc homeostasis is also affected in early pregnancy of smokers, and we know from pilot studies that even among women who want to keep their babies, the zinc status is low. Our findings support that zinc supplements should be considered in particular to women who smoke. STUDY FUNDING/COMPETING INTEREST(S): We thank the Department of Biomedicine for providing laboratory facilities and laboratory technicians and the Lundbeck Foundation and Læge Sofus Carl Emil Friis og Hustru Olga Doris Friis Legat for financial support. The authors have no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

Use of alternative medicine, ginger and licorice among Danish pregnant women - a prospective cohort study.

BACKGROUND: The use of alternative medicines and dietary supplements is constantly changing, as are dietary habits. One example of this phenomenon is the current popularity of ginger products as an everyday health boost. Ginger and licorice has also been shown to ameliorate nausea a common complaint in early pregnancy. Alternative medicines are often regarded as safe. However, they might affect fetal development, such as through alterations of hormone metabolism and cytochrome P450 function. Health care professionals may be unaware of the supplementation habits of pregnant women, which may allow adverse exposures to go unnoticed, especially if the rates of use in pregnancy are not known. We therefore investigated the use of alternative medicines and licorice among pregnant Danish women. METHODS: A total of 225 pregnant women were included in a prospective cohort when attending the national prenatal screening program at gestational weeks 10-16. Participants were asked to complete a questionnaire regarding their socio-economic status and lifestyle habits, including their intake of alternative medicine and licorice. RESULTS: We found that 22.7% of women reported taking alternative medicines, with 14.7% reporting daily consumption. Ginger supplements were consumed by 11.1%, mainly as health boost and 87.1% reported consumption of licorice. Regular or daily licorice consumption was reported by 38.2 and 7.1%, respectively. Notably, the use of licorice was reflected by an increase in blood pressure of the pregnant women. CONCLUSIONS: The use of licorice and alternative medicines appears to be common in pregnant Danish women, supporting the need for further investigations into the safety of alternative medicine use during pregnancy and the importance of up-to-date personalized counseling regarding popular health trends and lifestyle habits.

[Use of complementary and herbal medicine in the general population and among pregnant women].

Studies have reported a widespread use of herbal medicine in the general population (6-48%) and among pregnant women (4-69%) with great geographic and socio-economic variations in the extent of utilization and compounds used. The use of herbal medicine in Denmark remains relatively undescribed. Equivalent to conventional drugs, herbal medicine has side effects, interactions and contraindications. Thus, especially pregnant women should be careful as the safety profile remains unclear. Many patients do not report their use of herbal medicine to healthcare practitioners if they are not asked directly.

Expression Patterns and Correlations with Metabolic Markers of Zinc Transporters ZIP14 and ZNT1 in Obesity and Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is associated with infertility, increased androgen levels, and insulin resistance. In adipose tissue, zinc facilitates insulin signaling. Circulating zinc levels are altered in obesity, diabetes, and PCOS; and zinc supplementation can ameliorate metabolic disturbances in PCOS. In adipose tissue, expression of zinc influx transporter ZIP14 varies with body mass index (BMI), clinical markers of metabolic syndrome, and peroxisome proliferator-activated receptor gamma (PPARG). In this study, we investigated expression levels of ZIP14 and PPARG in subcutaneous adipose tissue of 36 PCOS women (17 lean and 19 obese women) compared with 23 healthy controls (7 lean and 16 obese women). Further, expression levels of zinc transporter ZIP9, a recently identified androgen receptor, and zinc efflux transporter ZNT1 were investigated, alongside lipid profile and markers of glucose metabolism [insulin degrading enzyme, retinol-binding protein 4 (RBP4), and glucose transporter 4 (GLUT4)]. We find that ZIP14 expression is reduced in obesity and positively correlates with PPARG expression, which is downregulated with increasing BMI. ZNT1 is upregulated in obesity, and both ZIP14 and ZNT1 expression significantly correlates with clinical markers of altered glucose metabolism. In addition, RBP4 and GLUT4 associate with obesity, but an association with PCOS as such was present only for PPARG and RBP4. ZIP14 and ZNT1 does not relate to clinical androgen status and ZIP9 is unaffected by all parameters investigated. In conclusion, our findings support the existence of a zinc dyshomeostasis in adipose tissue in metabolic disturbances including PCOS-related obesity.

The zinc transporter ZNT3 co-localizes with insulin in INS-1E pancreatic beta cells and influences cell survival, insulin secretion capacity, and ZNT8 expression.

Zinc trafficking in pancreatic beta cells is tightly regulated by zinc transporting (ZNTs) proteins. The role of different ZNTs in the beta cells is currently being clarified. ZNT8 transports zinc into insulin granules and is critical for a correct insulin crystallization and storage in the granules whereas ZNT3 knockout negatively affects beta cell function and survival. Here, we describe for the first time the sub-cellular localization of ZNT3 by immuno-gold electron microscopy and supplement previous data from knockout experiments with investigations of the effect of ZNT3 in a pancreatic beta cell line, INS-1E overexpressing ZNT3. In INS-1E cells, we found that ZNT3 was abundant in insulin containing granules located close to the plasma membrane. The level of ZNT8 mRNA was significantly decreased upon over-expression of ZNT3 at different glucose concentrations (5, 11 and 21 mM glucose). ZNT3 over-expression decreased insulin content and insulin secretion whereas ZNT3 over-expression improved the cell survival after 24 h at varying glucose concentrations (5, 11 and 21 mM). Our data suggest that ZNT3 and ZNT8 (known to regulate insulin secretion) have opposite effects on insulin synthesis and secretion possibly by a transcriptional co-regulation since mRNA expression of ZNT3 was inversely correlated to ZNT8 and ZNT3 over-expression reduced insulin synthesis and secretion in INS-1E cells. ZNT3 over-expression improved cell survival.

Effects of zinc supplementation and zinc chelation on in vitro ß-cell function in INS-1E cells.

BACKGROUND: Zinc is essential for the activities of pancreatic ß-cells, especially insulin storage and secretion. Insulin secretion leads to co-release of zinc which contributes to the paracrine communication in the pancreatic islets. Zinc-transporting proteins (zinc-regulated transporter, iron-regulated transporter-like proteins [ZIPs] and zinc transporters [ZnTs]) and metal-buffering proteins (metallothioneins, MTs) tightly regulate intracellular zinc homeostasis. The present study investigated how modulation of cellular zinc availability affects ß-cell function using INS-1E cells. RESULTS: Using INS-1E cells, we found that zinc supplementation and zinc chelation had significant effects on insulin content and insulin secretion. Supplemental zinc within the physiological concentration range induced insulin secretion. Insulin content was reduced by zinc chelation with N,N,N',N-tektrakis(2-pyridylmethyl)-ethylenediamine. The changes in intracellular insulin content following exposure to various concentrations of zinc were reflected by changes in the expression patterns of MT-1A, ZnT-8, ZnT-5, and ZnT-3. Furthermore, high zinc concentrations induced cell necrosis while zinc chelation induced apoptosis. Finally, cell proliferation was sensitive to changes in zinc the concentration. CONCLUSION: These results indicate that the ß-cell-like function and survival of INS-1E cells are dependent on the surrounding zinc concentrations. Our results suggest that regulation of zinc homeostasis could represent a pharmacological target.