Maternal plasma 25-hydroxyvitamin D concentrations and the risk for gestational diabetes mellitus

Impact of Vitamin D Deficiency on Gestational Diabetes and Pregnancy Outcomes Across Diverse Ethnic Groups: A Retrospective Cohort Study

Background: Vitamin D deficiency is linked to adverse pregnancy outcomes like gestational diabetes mellitus (GDM), but its effects across ethnic groups are unclear. This study examines the relationship among vitamin D levels, glucose tolerance, GDM prevalence, and neonatal outcomes in a multi-ethnic cohort of pregnant women. Methods: We conducted a retrospective analysis of 252 pregnant women from antenatal clinics between 2018 and 2022. Participants were divided into four groups based on serum vitamin D levels: severely deficient (<25 nmol/L), deficient (25-50 nmol/L), insufficient (51-75 nmol/L), and sufficient (>75 nmol/L). The analysis included multivariate linear regression models adjusted for age, ethnicity, BMI, gestational diabetes status, and seasonality. An area under the receiver operating characteristic (AUROC) analysis identified the vitamin D threshold linked to an increased GDM risk. Results: Women classified as severely deficient had higher fasting glucose levels (5.73 ± 1.24 mmol/L) than those in other groups (p = 0.003, adjusted). The AUROC analysis identified a vitamin D threshold of 45 nmol/L associated with an elevated GDM risk (AUROC = 0.78, CI: 0.70-0.85). South Asian women had lower vitamin D levels (41.17 ± 18.03 nmol/L vs. 45.15 ± 16.75 nmol/L) and higher glucose tolerance test (GTT) levels than Caucasian women, despite having lower BMIs. Moreover, vitamin D levels positively correlated with neonatal birth weight (p = 0.02). Conclusions: There is a strong link between vitamin D deficiency and increased GDM risk, especially among South Asian women. These findings underscore the need for targeted interventions to improve vitamin D levels in high-risk ethnic groups.

Pre-pregnancy LDL/HDL and total Cholesterol/HDL ratios are strong predictors of gestational diabetes mellitus in women undergoing assisted reproductive technologies

BACKGROUND & OBJECTIVE

To analyze whether there is an association between pre-pregnancy lipid parameters and gestational diabetes mellitus (GDM) in women undergoing assisted reproductive technologies (ART), a group especially at risk for GDM, and if so, which parameter is associated the strongest.

METHODS

Data was collected at the Reproductive and Genetic Hospital CITIC-Xiangya in Changsha, China from January 2017 to December 2018. The measured lipid parameters include LDL (low-density lipoprotein), HDL (high-density lipoprotein), TC (total cholesterol), and TG (triglycerides).

RESULTS

119 (15.5%) of the 767 patients developed GDM. On average, women who developed GDM were older, had a higher BMI, LDL, TC, and TG, and lower HDL. After adjusting for confounders, LDL and HDL showed a significant association with GDM (p < 0.05), but TC and TG did not. Binary LDL/HDL and TC/HDL ratios showed the strongest association with GDM incidence (OR 1.957 [95%CI 1.258-3.044] and 1.942 [1.243-3.034] respectively). Subgroup analysis showed that an elevated LDL/HDL ratio also increased GDM risk in subgroups with a typically lower prevalence of GDM, such as young women with a low BMI and low blood pressure. Both lipid ratios (LDL/HDL and TC/HD) show strong interactions with baseline age, fasting plasma glucose, and LH.

CONCLUSIONS

In this cohort of Chinese women undergoing ART, pre-pregnancy LDL/HDL and TC/HDL were associated with GDM the strongest from the lipid parameters and could be useful to estimate GDM risk even before ART treatments and pregnancy.

CLINICAL TRIAL NUMBER

NCT03503006 registered on the 21st of March 2018 (on clinicaltrials.gov). https://clinicaltrials.gov/study/NCT03503006?locStr=Changsha,%20Hunan,%20China&country=China&state=Hunan&city=Changsha&cond=ivf&rank=2 .

Micronutrient interactions: Magnesium and its synergies in maternal-fetal health

Magnesium is an essential nutrient for various physiological processes and becomes even more vital during pregnancy, contributing to muscle relaxation, bone development, electrolyte balance, and blood pressure regulation. Despite the fact that the dietary sources of magnesium are diversified, it is still challenging to obtain it in sufficient quantities during pregnancy. We have elucidated its interactions and its specific impact on maternal-fetal health in different research publications. Magnesium also interacts synergistically with other micronutrients like calcium, vitamin D, potassium, zinc, iron, and vitamin B6, emphasizing its significance in promoting optimal outcomes for both the mother and the fetus. Inadequate magnesium intake during pregnancy has been linked to complications like gestational diabetes, preeclampsia, preterm birth, and low birth weight. Therefore, there should be an emphasis on the importance of maintaining adequate magnesium levels through a balanced diet and supplementation. This research therefore studies the complex mechanisms of micronutrient interactions and their specific impacts on maternal-fetal health to enhance prenatal care practices.

To Study the Correlation of Maternal Serum Vitamin D Levels and Infant Serum Vitamin D Levels With Infant Birth Weight: A Single-Centre Experience From the Bundelkhand Region, India

BACKGROUND

Vitamin D deficiency during pregnancy can have severe effects on both the mother and the newborn child. The main aim of this study was to assess the impact of maternal vitamin D levels on the birth weight of the newborn by analysing the vitamin D levels in pregnant women at full term and their newborn.

MATERIAL AND METHODS

The cross-sectional, hospital-based study was conducted with 150 consecutive women in labour presenting with a singleton term pregnancy at a large tertiary centre in the Bundelkhand region, India. Maternal and infant blood samples were obtained at the time of delivery. Umbilical cord blood was collected from infants, while maternal venous blood was drawn simultaneously. All relevant data were gathered, including the assessment of 25-hydroxy vitamin D3 levels in both mother and infant. The birth weight of the infant was measured, and statistical analysis was performed to find an association between maternal vitamin D level to birth weight and vitamin D level of the infant.

RESULT

Most pregnant women had low vitamin D levels in this study. The results revealed a significant positive correlation between maternal serum vitamin D levels and infant birth weight (p < 0.001), suggesting that lower maternal vitamin D levels were associated with low birth weight in infants. Additionally, infant serum vitamin D levels showed a positive correlation with maternal vitamin D levels (p < 0.001), indicating that higher maternal vitamin D levels tend to have infants with higher vitamin D levels at birth.

CONCLUSION

These findings suggest a potential correlation of maternal vitamin D status to birth weight and vitamin D level of newborns, and further research is needed to confirm and better understand this relationship. Additionally, other factors such as maternal nutrition, genetics, lifestyle factors, and environmental influences may contribute to birth weight outcomes.

The Impact of Vitamin D Deficiency on Gestational Diabetes Mellitus Risk: A Retrospective Study

Background Nowadays, there has been growing attention to vitamin D deficiency's impact on women of reproductive age, both during pregnancy and the preconception period. Because of its possible impact on female reproductive ability, vitamin D deficiency may have multiple implications for maternal and fetal health. Currently, the correlation between vitamin D deficiency and gestational diabetes mellitus (GDM) is gaining attention, mainly due to contradictory findings in the literature. Methods We conducted a single-center, retrospective study involving data from 106 pregnant women to establish a possible link between vitamin D deficiency and GDM risk. We analyzed variables such as vitamin D status, the occurrence of gestational diabetes, and body mass index to identify significant statistical correlations among them. Results Within our study group, the average vitamin D level was 19.5 ± 7.8 ng/mL. Regarding vitamin D status, 59 (55.7%) pregnant women had vitamin D deficiency, 36 (34%) had vitamin D insufficiency, and 11 (10.4%) had optimal vitamin D levels. GDM was diagnosed in 18 cases, representing 17%. After the statistical analysis, we found a positive correlation between gestational diabetes and vitamin D deficiency (chi-square = 4.472, p = 0.049). However, we did not find a significant correlation between gestational diabetes and optimal vitamin D status. Conclusions Pregnant women with vitamin D deficiency are at an increased risk of developing GDM and may benefit from vitamin D supplementation. We believe that further research is necessary to have a comprehensive understanding of vitamin D's effects on pregnancy.

Supplementation with vitamin D improves the embryo quality in in vitro fertilization (IVF) programs, independently of the patients' basal vitamin D status

PURPOSE

The study aims to demonstrate the effects of Vitamin D (VD) supplementation, prior to oocyte pick-up within IVF protocols, in women with diverse VD status at the enrollment.

METHODS

A total of 204 women eligible for intra-cytoplasmatic sperm injection (ICSI) cycles were included in the study and two homogeneous groups were selected from the database. Both group of patients with normal VD baseline level (> 40 ng/ml) and patients with low VD baseline level (< 20 ng/ml) were divided into control group and treatment group. The control group followed the standard procedure. The treatment group was supplemented with vitamin D3 as cholecalciferol in combination with Myo-Inositol, folic acid, and melatonin 3 months before standard procedure, once a day in the evening.

RESULTS

VD levels significantly increased in the study group of low baseline VD, both in serum and in the follicular fluid compared to controls. The treatment induced a significant improvement of the embryo quality in both group of patients considered.

CONCLUSION

Supplementation of VD in patients undergoing ICSI procedures significantly improved the number of top-quality embryos compared with the control group, either starting from VD normal baseline values or starting from low values.

TRIAL REGISTRATION NUMBER

07/2018.

Vitamin D and reproductive disorders: a comprehensive review with a focus on endometriosis

Vitamin D is a fat-soluble steroid hormone that was initially known only for regulating calcium and phosphorus levels and maintaining bone health. However, it was later discovered that many organs express vitamin D metabolizing enzymes and have a ligand for vitamin D, which regulates the expression of an extensive assortment of genes. As a result, vitamin D is indispensable for the proper function of organs, and its deficiency is believed to be a critical factor in symptoms and disorders such as cardiovascular diseases, autoimmune diseases, and cancers. The significance of vitamin D in reproductive tissues was recognized later, and studies have revealed its crucial role in male and female fertility, as well as proper reproductive function during pregnancy. Vitamin D deficiency has been identified as a risk factor for infertility, gonadal cancers, pregnancy complications, polycystic ovary syndrome, and endometriosis. However, data investigating the association between vitamin D levels and reproductive disorders, including endometriosis, have encountered inconsistencies. Therefore, the present study aims to review existing research on the effect of vitamin D on proper reproductive function, and the role of deficiency in reproductive diseases and specifically focuses on endometriosis.

Vitamin D supplementation modulates glycated hemoglobin (HBA1c) in diabetes mellitus

Diabetes is a metabolic illness that increases protein glycosylation in hyperglycemic conditions, which can have an impact on almost every organ system in the body. The role of vitamin D in the etiology of diabetes under RAGE (receptor for advanced glycation end products) stress has recently received some attention on a global scale. Vitamin D's other skeletal benefits have generated a great deal of research. Vitamin D's function in the development of type 1 and type 2 diabetes is supported by the discovery of 1,25 (OH)2D3 and 1-Alpha-Hydroylase expression in immune cells, pancreatic beta cells, and several other organs besides the bone system. A lower HBA1c level, metabolic syndrome, and diabetes mellitus all seems to be associated with vitamin D insufficiency. Most of the cross-sectional and prospective observational studies that were used to gather human evidence revealed an inverse relationship between vitamin D level and the prevalence or incidence of elevated HBA1c in type 2 diabetes. Several trials have reported on the impact of vitamin D supplementation for glycemia or incidence of type 2 diabetes, with varying degrees of success. The current paper examines the available data for a relationship between vitamin D supplementation and HBA1c level in diabetes and discusses the biological plausibility of such a relationship.

Predicting comorbidities of pregnancy: A comparison between total and free 25(OH)D and their associations with parathyroid hormone

Pregnancy is a unique time when amplified sex steroid concentrations promote an escalation in vitamin D binding protein (DBP) synthesis, associated with increased total vitamin D and metabolites, including 25-hydroxyvitamin D (25(OH)D). Free 25(OH)D concentration increases disproportionately to total 25(OH)D during pregnancy, likely an adaptation to supply the woman and fetus with readily available 25(OH)D. Highlighting the importance of the calcium metabolic stress during pregnancy, the interactional relationship between serum 25(OH)D and PTH has been evaluated. Maternal total 25(OH)D and total 25(OH)D/iPTH are measures of vitamin D status and biomarkers for potential pregnancy complications. It has been proposed that free 25(OH)D and free 25(OH)D/iPTH could be better indicators of vitamin D status and predictors of pregnancy complications such as gestational diabetes (GDM), hypertensive disorders of pregnancy, and preterm delivery. This study aims to determine if free 25(OH)D and its association with PTH are more accurate predictors of comorbidities of pregnancy than total 25(OH)D and its association with PTH. In this post hoc analysis of the Kellogg Pregnancy Study, a double-blind randomized placebo-controlled trial, participants included 297 women with singleton pregnancies: 191 participants were randomized into a group receiving a daily prenatal (400 IU vitamin D3) while 196 received a prenatal plus extra supplementation (4400 IU vitamin D3). Blood and urine samples were collected monthly. 297 participants' serum total 25(OH)D concentrations were measured using radioimmunoassay at baseline (visit 1) and 5-7 months' gestation (visit 6-7). 93 participants' serum free 25(OH)D and PTH concentrations were measured using ELISA and immunoradiometric assay, respectively, at visit 1 and 6-7; 66 participants had paired samples and were included in this analysis. Data were analyzed using SAS 9.4, Cary, N.C. or SPSS v28, IBM Corporation, Armonk, N.Y. Results were considered significant with a p < 0.05. A significant relationship exists between the ratio of total 25(OH)D/iPTH and free 25(OH)D/iPTH grouped by total 25(OH)D ≥ 30 ng/mL and < 30 ng/mL as an indicator of maternal vitamin D status. There was a statistically significant relationship between lower mean free 25(OH)D/iPTH and the development of GDM at visit 1 (p = 0.0003) and at visit 6-7 (p = 0.001) while total 25(OH)D/iPTH and GDM were significantly related only at visit 1 (p = 0.029). In this exploratory cohort, neither free 25(OH)D/iPTH nor total 25(OH)D/iPTH were significantly associated with increased incidence of preterm delivery, hypertensive disorders, or combined comorbidities of pregnancy. An univariate logistic regression evaluating the outcome of gestational diabetes while independently controlling for independent factors showed the ratio of free 25(OH)D/iPTH was more closely associated with gestational diabetes than the ratio of total 25(OH)D/iPTH, although neither were significant. This proof-of-concept analysis suggests that the ratio of free 25(OH)D/iPTH is associated with the development of gestational diabetes throughout pregnancy while total 25(OH)D/iPTH is only associated with the outcome early in pregnancy. Further investigation is warranted to explore this relationship between calcium metabolic stress during pregnancy with a larger cohort to improve validity,reproducibility, and relevance to other pregnancy comorbidities.

Influence of temperature on the risk of gestational diabetes mellitus and hypertension in different pregnancy trimesters

Previous studies have proved that exposure to extreme temperature in specific windows of pregnancy could cause some complications, such as pregnancy induced hypertension (PIH) and gestational diabetes mellitus (GDM), but differences in the effect of extreme temperature on the 2 complications are rarely studied. We carried a retrospective study on the impact of temperature on GDM/PIH in different trimesters based on data from a maternal and child health center in Beijing, China. Ambient temperatures (°C) were obtained from the China Meteorological Administration from January 1st, 2013 to May 15th, 2018. We use distributed lag non-linear models (DLNMs) combined with logistic regression to calculate the lag exposure-response relationships between the temperature and GDM/PIH from 1st to 24th/20th weeks of pregnancy. In both first and second trimesters, the risk of GDM was increased in summer with high temperatures; in second trimester, the risk of GDM increased in winter with low temperatures. In first half of pregnancy, risk of PIH was decreased in winter with low temperatures. These findings can provide the guideline for preventing the GDM and PIH induced by extreme temperature during pregnancy.

The Degree of Prepregnancy Vitamin D Deficiency Is Not Associated With Gestational Diabetes in Women Undergoing ART

Context

Gestational diabetes mellitus (GDM) is a common pregnancy complication, particularly in women undergoing assisted reproductive technology (ART). An association of GDM with vitamin D in women conceiving naturally has been described; however, studies have yielded heterogeneous results.

Objective

To analyze the association between prepregnancy total and free vitamin D and GDM incidence in women undergoing ART.

Methods

Post hoc analysis of a prospective study at the Reproductive and Genetic Hospital of CITIC-Xiangya in Changsha, China. Total and free vitamin D were measured 1 day before embryo transfer. The patients were screened for GDM using the oral glucose tolerance test.

Results

A total of 1593 women were included in the study, among whom 256 (16.1%) developed GDM. According to international guidelines for total 25-hydroxyvitamin D [25(OH)D], 47 (2.9%) patients had sufficient (≥30 ng/mL) levels, while 696 (43.7%) were insufficient (20 to <30 ng/mL) and 850 (54.4%) were deficient (<20 ng/mL). Comparing GDM and non-GDM patients, there was no significant difference in total nor free vitamin D levels (P = .340 and .849). Similarly, analysis of GDM rates by quintiles of total and free 25(OH)D showed no significant association in one-way ANOVA (P = .831 and .799). Multivariate logistic regression, considering age, BMI, and fasting glucose, also did not show a significant influence of the 2 vitamin D forms on GDM incidence (P = .266 and .123 respectively).

Conclusion

In this relatively vitamin D deficient/insufficient ART cohort, the degree of neither total nor free vitamin D deficiency before pregnancy was associated with the occurrence of GDM.

Analysis of single nucleotide polymorphisms associated with the vitamin D pathway in the placentas of women with gestational diabetes mellitus: a laboratory study

BACKGROUND

The aim of this study was to analyze the single nucleotide polymorphisms (SNPs) of genes known to be involved in vitamin D metabolism in the placenta using the placental tissue of mothers diagnosed with gestational diabetes mellitus (GDM) to determine whether the SNPs and occurrence of GDM are related.

METHODS

We enrolled 80 women of the same gestational age, 40 with and 40 without GDM. The placenta was obtained from each woman after delivery and SNP genotyping was performed on seven SNPs in the CYP27B1 (rs10877012), CYP24A1 (rs2248359, rs6013897, and rs2209314), and GC (rs2282679, rs16847024, and rs3733359) genes. Maternal serum 25-hydroxyvitamin D levels were measured during the first trimester of pregnancy and before delivery.

RESULTS

At the time of delivery, vitamin D levels were lower (21.05±12.05 mg/dL vs. 31.31±20.72 mg/dL, p=0.012) and the frequency of vitamin D deficiency was higher (60.7% vs. 32.5%, p=0.040) in the GDM group. In women with GDM, the G allele of rs10877012 was more common (86.3% vs. 65.0%, p=0.002). The rs10877012 GG genotype was more common in the GDM group (72.5% vs. 42.5%, p=0.007) and the rs10877012 TT genotype was more common in the control group (12.5% vs. 0%, p=0.007).

CONCLUSION

Mothers with GDM have lower serum concentrations of vitamin D before delivery than healthy controls and vitamin D deficiency is common. A polymorphism in CYP27B1 (rs10877012), is considered to be a cause of GDM pathogenesis.

Knowledge domain and research trends for Gestational Diabetes Mellitus and nutrition from 2011 to 2021: a bibliometric analysis

Objective

Nutrient management and lifestyle changes are the frontlines of treatment for all pregnant women diagnosed with Gestational Diabetes Mellitus (GDM). This study aimed to identify the global research architecture, trends, and hotpots of GDM and nutrition.

Methods

We obtained publications from the sub-databases of Science Citation Index Expanded and Social Science Citation Index sourced from the Web of Science Core Collection database on January 4, 2022, using publication years between 2011 and 2021. CiteSpace software, VOSviewer, and Microsoft Excel 2019 were used to conduct the bibliometric analyses.

Results

A growing publication trend was observed for GDM and nutrition, and this field has great potential. More GDM and nutrition research has been conducted in developed countries than developing countries. The top three authors with a high publication frequency, co-citations, and a good h-index were from the United States. There were the four studies of randomized controlled trials (RCTs) or meta-analyses of RCTs, as well as one review in the top five items of cited literature. Keywords were categorized into four clusters based on the keywords visualization.

Conclusion

It is important to strengthen the collaboration between nations of different economies to produce more high-quality research on GDM and nutrition. It may be beneficial to further study the etiology, diagnosis, and treatment of GDM based on current results to provide a new perspective on GDM and nutrition.

Vitamin D deficiency and associated factors among antenatal care attending pregnant women in Sodo town, South Ethiopia: A facility-based cross-sectional study

BACKGROUND

Vitamin D deficiency is an emerging public health problem globally, with devastating health consequences. Pregnant women are most susceptible for Vitamin D deficiency, and black women particularly are under double burden of the problem. Therefore, this study aimed to determine the prevalence of Vitamin D deficiency and identify associated factors among antenatal care attending pregnant women.

METHODS

A facility-based cross-sectional study involving 331 pregnant women was conducted from March to April in 2021. Systematic random sampling technique was used to select the study participants from antenatal care service providing facilities. Data were collected by using interviewer-administered questionnaire and 5ml of blood sample was collected using aseptic techniques. Data were entered into Epi Data software version 3.1 and exported to SPSS version 20 for analysis. Binary logistic regression analysis was used to identify the associated factors.

RESULTS

In this study, about 39% of the women were Vitamin D deficient; of which 8.8% were severely deficient. The mean serum Vitamin D level was 24.43ng/ml. Women with Body Mass Index (BMI) ≥30 (AOR = 47.31; 95% CI: 3.94, 567.70) and who never ate egg had a higher chance of being Vitamin D deficient (AOR = 7.48; 95% CI: 1.02, 55.05). On the other hand, women who were exposed to mid-day time sunlight (AOR = 0.30; 95% CI: 0.11, 0.77) were less likely to become Vitamin D deficient.

CONCLUSIONS

Vitamin D deficiency is higher among obese women and women who did not consume egg. Being exposed to mid-day sunlight is protective against Vitamin D deficiency. Having optimal body weight, mid-day sun light exposure and consumption of Vitamin D rich diet might contribute to reduce the risk of Vitamin D deficiency.

Maternal vitamin D levels correlate with fetal weight and bone metabolism during pregnancy: a materno-neonatal analysis of bone metabolism parameters

OBJECTIVES

Vitamin D plays an essential role in neonatal skeletal development and maternal weight gain during pregnancy. We aim to study the association between vitamin D status, maternal weight, and materno-neonatal bone metabolism parameters.

METHODS

From January to June 2017, we conducted this cross-sectional study among 103 pregnant women (21-42 years old) and their singletons. The levels of serum 25-(OH)D, PTH, P1NP, OC, and CTX were measured for mothers and neonates (cord blood). Serum vitamin D and OC were measured using chemiluminescence and two-site immunoradiometric assay, respectively. Meanwhile, P1NP, CTX, and PTH were measured by ELISA.

RESULTS

The average serum vitamin D levels from mothers were 15.1 ng/mL during pregnancy and 16.2 ng/mL in the umbilical cord. At baseline, vitamin D deficient mothers were more likely to have higher PTH (36.4 vs. 18 pg/mL; p=0.029) and lower P1NP levels (90 vs. 92.5 ng/mL; p=0.026). Also, vitamin D deficient status was associated with lower fetal weight (3,293 vs. 3,358 g; p=0.019). Maternal weight was significantly correlated with P1NP (65.86 vs. 109.35; p=0.001) and OC (14.52 vs. 18.24; p=0.038), as well as cord vitamin D level (13.31 vs. 18.46; p=0.039) among normal vs. overweight women. No significant differences were found for the correlation between maternal weight and fetal parameters except for fetal weight which significantly increased with the increase in maternal weight (overweight vs. obese women=3,280 vs. 3,560; p=0.06).

CONCLUSIONS

Maternal vitamin D status is associated with maternal and neonatal bone metabolism parameters as well as maternal and neonatal weight.

Effect of supplementation with 5,000 IU of vitamin D on the glycemic profile of women with gestational diabetes mellitus

OBJECTIVES

The frequency of GDM and vitamin D insufficiency in Mexico is high. Vitamin D supplementation in GDM patients has shown favorable but non-homogeneous results regarding improvement of glycemic profile. The aim of the study was to assess the effects of supplementing with 5,000 IU of vitamin D on the glycemic profile of women with GDM.

METHODS

A randomized clinical trial was conducted on women with GDM who received 5,000 IU of vitamin D (n=27) or a placebo (n=27) for eight weeks. Changes in vitamin D levels and metabolic parameters before and after the intervention were analyzed.

RESULTS

Vitamin D vs. placebo: 25-OHD (32 vs. 26 ng/mL, p=0.006), HbA_1c (6.0 vs. 6.1%, p=0.29), glucose (99 vs. 87 mg/dL, p=0.29), insulin (14 vs. 13 µIU/mL, p=0.79), HOMA-IR (3.6 vs. 2.6, p=0.55), QUICKI (0.31 vs. 0.33, p=0.55).

CONCLUSIONS

Supplementation with 5,000 IU of vitamin D for eight weeks had no significant effect on the glycemic profile.

Particulate matter may have a limited influence on maternal vitamin D levels

Evidence for an association between the amount of particulate matter (PM) in the atmosphere and vitamin D status of pregnant women is limited. We aimed to examine the independent association between PM and maternal levels of serum 25-hydroxyvitamin D (25OHD) during the second trimester and to explore possible modifications to the association by meteorological factors. 27,768 pregnant women presenting for prenatal examination who were tested for serum 25OHD concentration during the second trimester between January 1, 2016, and December 31, 2020, were included in this retrospective analysis. Exposure to PM was evaluated based on daily average PM with an aerodynamic diameter of ≤ 2.5 μm (PM_2.5) and PM with an aerodynamic diameter of ≤ 10 μm (PM₁₀). Corresponding meteorological data for daily average atmospheric temperature, atmospheric pressure, relative humidity, sunshine duration, and wind speed were collected. The maximum cumulative effects of PM_2.5 occurred at lag 45 days, and the maximum cumulative effects of PM₁₀ occurred at lag 60 days. In crude models, 45-day moving daily average PM_2.5 concentrations were negatively associated with 25OHD levels (β, − 0.20; 95% CI − 0.21 to − 0.19), as were 60-day moving daily average PM₁₀ concentrations (β, − 0.14; 95% CI − 0.15 to − 0.14). After adjusting for temporal and meteorological factors, the effect values were drastically reduced (adjusted β of PM_2.5, − 0.032; 95% CI − 0.046 to − 0.018; adjusted β of PM₁₀, − 0.039; 95% CI − 0.049 to − 0.028). Our study showed there was a small, independent, negative association between PM in the atmosphere and maternal serum 25OHD levels during the second trimester of pregnancy after adjusting for temporal and/or meteorological factors, which indicates that PM may have a limited influence on maternal serum 25OHD levels. Besides taking vitamin D supplements, pregnant women should keep participating in outdoor activities while taking PM protection measures to improve their vitamin D levels when PM levels are high in winter and spring.

Vitamin D Deficiency During the First Trimester of Pregnancy and the Risk of Developing Gestational Diabetes Mellitus

OBJECTIVE

To investigate the relationships among various factors that affect serum vitamin D levels and vitamin D in the first trimester and the risk of developing gestational diabetes mellitus (GDM).

DESIGN

A prospective cohort design.

SETTING

The family health center of Ankara, Turkey.

PARTICIPANTS

Out of 889 pregnant women who participated in the study in the first trimester (6-13 weeks gestation), 814 participated in GDM screening in the second trimester (24-28 weeks gestation).

METHODS

We determined serum vitamin D levels, demographic data, various biochemical and anthropometric parameters, and factors that affect vitamin D synthesis of participants in the first trimester and used logistic regression analysis to analyze the effects of the associations among vitamin D deficiency and the other variables on the occurrence of GDM.

RESULTS

Vitamin D deficiency in the first trimester was present in 425 (82.5%) participants. In the second trimester, 198 participants (24.3%) were diagnosed with GDM through oral glucose tolerance test screening. We detected GDM in the second trimester in 5.7% of participants who had vitamin D deficiency in the first trimester. Even after adjustment for vitamin D intake, clothing style, and duration of exposure to the sun, the risk of GDM was significantly greater in participants who were vitamin D deficient than those who were not deficient. The risk of GDM among women with vitamin D deficiency was sustained or increased significantly after we adjusted for age, parity, prepregnancy body mass index, history of diabetes, triglyceride levels, vitamin D intake, clothing style, and length of sun exposure, OR = 10.60, p < .001, 95% confidence interval [2.82, 39.76].

CONCLUSIONS

Our results suggest that vitamin D deficiency in the first trimester may significantly increase the risk of developing GDM.

Influence of Diet and Lifestyle on the Development of Gestational Diabetes Mellitus and on Perinatal Results

GDM is a multifactorial disease, so there is controversy regarding the mechanisms involved in its pathogenesis. We speculate whether lifestyle and eating habits influenced the appearance and pathogenesis of GDM. To explore this issue, the aim of the present study was to analyze maternal diet and lifestyle characteristics in early pregnancy and their influence on the development of GDM. The study included 103 pregnant women who completed a questionnaire on nutritional knowledge, lifestyle and eating habits. Perinatal and biochemical outcomes as well as pregestational lifestyle and eating habits were compared between normoglycemic women and those who developed GDM. The results obtained showed that women who developed GDM had erroneous knowledge regarding nutrition. Consumption of white bread (p = 0.018), added sugars (p = 0.037), legumes (p = 0.025), fish (p = 0.014), butter (p = 0.010) and the performance of less physical activity (p = 0.024) correlated with glucose intolerance in pregnant women. In conclusion, we found a relationship between dietary and lifestyle habits at the beginning of pregnancy and the later diagnosis of GDM.

Vitamin D Status and Gestational Diabetes in Russian Pregnant Women in the Period between 2012 and 2021: A Nested Case-Control Study

Several meta-analyses found an association between low maternal serum 25-hydroxyvitamin D (25(OH)D) level and gestational diabetes mellitus (GDM). However, some of them reported significant heterogeneity. We examined the association of serum 25(OH)D concentration measured in the first and in the second halves of pregnancy with the development of GDM in Russian women surveyed in the periods of 2012−2014 and 2018−2021. We conducted a case−control study (including 318 pregnant women) nested on two previous studies. In 2012−2014, a total of 214 women (83 GDM and 131 controls) were enrolled before 15 weeks of gestation and maternal serum 25(OH)D concentrations were measured twice: at 8th−14th week of gestation and simultaneously with two-hour 75 g oral glucose tolerance test (OGTT) at 24th−32nd week of gestation. In the period of 2018−2021, 104 women (56 GDM and 48 controls) were included after OGTT and 25(OH)D concentrations were measured at 24th−32nd week of gestation. Median 25(OH)D levels were 20.0 [15.1−25.7] vs. 20.5 [14.5−27.5] ng/mL (p = 0.565) in GDM and control group in the first half of pregnancy and 25.3 [19.8−33.0] vs. 26.7 [20.8−36.8] ng/mL (p = 0.471) in the second half of pregnancy, respectively. The prevalence rates for vitamin D deficiency (25(OH)D levels < 20 ng/mL) were 49.4% and 45.8% (p = 0.608) in the first half of pregnancy and 26.2% vs. 22.1% (p = 0.516) in the second half of pregnancy in women who developed GDM and in women without GDM, respectively. The frequency of vitamin D supplements intake during pregnancy increased in 2018−2021 compared to 2012−2014 (p = 0.001). However, the third trimester 25(OH)D levels and prevalence of vitamin D deficiency (25.5 vs. 23.1, p = 0.744) did not differ in women examined in the periods of 2012−2014 and 2018−2021. To conclude, there was no association between gestational diabetes risk and maternal 25(OH)D measured both in the first and in the second halves of pregnancy. The increased prevalence of vitamin D supplements intake during pregnancy by 2018−2021 did not lead to higher levels of 25(OH)D.

Prevalence of Vitamin D Deficiency and Insufficiency in Kosovo Population

BACKGROUND: Vitamin D deficiency is a global health problem, but it is not known about its status in the Kosovo population. AIM: The purpose of this study is to determine the status of Vitamin D deficiency and insufficiency in our population. MATERIALS AND METHODS: Data collection was done from January 2020 to July 2021, during which period blood samples were collected. The sampling was done for 769 selected subjects and statistical data (frequency, mean values, and standard deviation) have been analyzed for 25-hydroxyvitamin D [25(OH)D] concentration. They were categorized by age group, gender, and level of 25(OH)D. The prevalence and percentage of Vitamin D deficiency and insufficiency in the study population were evaluated. RESULTS: The mean concentration of 25(OH)D in the serum of the study group was 18.3 ng/ml. The mean value was significantly lower for females when compared for that of males (17.89 and 19.58 ng/ml, respectively), with p < 0.0035, but there was no significant difference between age groups. The level of 25(OH)D less than 20 ng/ml was observed in 62% of the cases in our study population with a slight difference between female (63.6%) and male (57.2%) group. The age group of >60 had 25(OH)D deficiency in 62.3% of cases when compared to other age group categories. Vitamin D deficiency was present in 20.2% of cases; meanwhile, its insufficiency was present in 41.9% of cases. Vitamin D deficiency was observed in 21.1% of females and 17.1% of males, while 42.4% of females, respectively, and 40.1% of males had Vitamin D insufficiency. CONCLUSION: The mean values of 25(OH)D in the study population are relatively low, which corresponds to significant Vitamin D deficiency and insufficiency in all age groups, and which may also have serious implications for their overall health.

Vitamin D supplementation higher than 2000 IU/day compared to lower dose on maternal-fetal outcome: Systematic review and meta-analysis

INTRODUCTION

Although vitamin D is widely known as an essential micronutrient during pregnancy, the exact supplementation dose to prevent maternal-fetal outcomes remains a question. This study aims to provide a systematic review and a meta-analysis of data from randomized controlled trial on > 2000 IU/day vitamin D supplementation compared to ⩽ 2000 IU/day; and ⩽ 2000 IU/day compared to placebo, on their effects on the incidence of preeclampsia, gestational diabetes mellitus, preterm birth, and differences on birth weight.

METHODS

A systematic literature search on PubMed, EBSCO-MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases was carried out to evaluate randomized controlled trial studies on the effects of oral vitamin D > 2000 IU/day versus ⩽ 2000 IU/day; and ⩽ 2000 IU/day versus placebo, on preeclampsia, gestational diabetes mellitus, preterm birth and birth weight. Risk ratio, mean difference, and 95% confidence interval were calculated.

RESULTS

There were a total of 27 randomized controlled trials selected. Maternal vitamin D supplementation > 2000 IU/day had a positive effect only on gestational diabetes mellitus (seven randomized controlled trials; risk ratio = 0.70, 95% confidence interval: 0.51-0.95, I2 = 0). Vitamin D supplementation ⩽ 2000 IU/day has reduced the risk of preeclampsia (three randomized controlled trials; risk ratio = 0.29, 95% confidence interval: 0.09-0.95, I2 = 0), with no significant difference when compared to > 2000 IU/day (eight randomized controlled trials; risk ratio = 0.80, 95% confidence interval: 0.51-1.24, I2 = 31). No difference in preterm birth risk and birth weight after vitamin D supplementation. The quality of evidence varies from moderate to very low certainty. The risk of preeclampsia and gestational diabetes mellitus after high-dose versus low-dose vitamin D supplementation was the ones with moderate certainty.

CONCLUSION

Vitamin D supplementation > 2000 IU/day might be important to reduce the risk of gestational diabetes mellitus. Lower dose vitamin D supplementation (⩽ 2000 IU/day) seemed adequate to reduce the risk of preeclampsia, with no significant difference compared to the higher dose.

Association between maternal vitamin D levels and risk of adverse pregnancy outcomes: a systematic review and dose-response meta-analysis

Epidemiological studies have investigated the associations between vitamin D and the risk of adverse pregnancy outcomes; however, the results are conflicting and dose-response relationships remain to be confirmed. This study aimed to summarize previous studies on the associations of vitamin D levels with the risk of gestational diabetes mellitus (GDM), pre-eclampsia (PE), gestational hypertension (GH), and caesarean section (C-section), and to clarify the dose-response trends. PubMed, Embase, Scopus, and Web of Science were searched to identify eligible articles. A total of 69 prospective observational studies including cohort studies, case-cohort studies, or nested case-control studies were included in the current systematic review, of which 68 studies were available for meta-analysis. Compared with the lowest level, the highest level of 25(OH)D was significantly associated with a lower risk of GDM (RR: 0.76; 95% CI: 0.66-0.87), PE (RR: 0.74; 95% CI: 0.60-0.90;), and GH (RR: 0.87; 95% CI: 0.79-0.97); however, no significant relationship was found for C-section (RR: 1.00; 95% CI: 0.90-1.12). There was significant between-study heterogeneity for GDM (I² = 69.2%; P_{heterogeneity} < 0.001), PE (I² = 52.0%; P_{heterogeneity} = 0.001), and C-section (I² = 59.1%; P_{heterogeneity} < 0.001), while no heterogeneity was found for GH (I² = 0.0%; P_{heterogeneity} = 0.676). For each 25 nmol L^-1 increase in 25(OH)D, the pooled RR was 0.92 (95% CI: 0.86-0.97) for GDM and 0.89 (95% CI: 0.84-0.94) for PE, respectively. Notably, the dose-response analysis showed a non-linear relationship between maternal 25(OH)D levels and the risk of PE (P_{non-linearity} = 0.009). Our meta-analysis provides further scientific evidence of the inverse association between 25(OH)D levels and the risk of GDM, PE, and GH, which may be useful for the prevention of pregnancy complications. However, more evidence from prospective studies is needed regarding the dietary intake of vitamin D during pregnancy.

Impact evaluation of the efficacy of different doses of vitamin D supplementation during pregnancy on pregnancy and birth outcomes: a randomised, controlled, dose comparison trial in Pakistan

BACKGROUND

Vitamin D deficiency during pregnancy is a public health problem in Pakistan and is prevalent among most women of reproductive age in the country. Vitamin D supplementation during pregnancy is suggested to prevent adverse pregnancy outcomes and vitamin D deficiency in both the mother and her newborn.

METHODS

We conducted a double-blinded, randomised controlled trial in Karachi, Pakistan to evaluate the effect of different doses of vitamin D supplementation during pregnancy on biochemical markers (serum 25(OH)D, calcium, phosphorus and alkaline phosphatase) in women and neonates, and on pregnancy and birth outcomes (gestational diabetes, pre-eclampsia, low birth weight, preterm births and stillbirths).

RESULTS

Pregnant women (N=350) in their first trimester were recruited and randomised to three treatment groups of vitamin D supplementation: 4000 IU/day (group A, n=120), 2000 IU/day (group B, n=115) or 400 IU/day (group C, n=115). Women and their newborn in group A had the lowest vitamin D deficiency at endline (endline: 75.9%; neonatal: 64.9%), followed by group B (endline: 84.9%; neonatal: 73.7%) and then the control group (endline: 90.2%; neonatal: 91.8%). Vitamin D deficiency was significantly lower in group A than in group C (p=0.006) among women at endline and lower in both groups A and B than in the control group (p=0.001) in neonates. Within groups, serum 25(OH)D was significantly higher between baseline and endline in group A and between maternal baseline and neonatal levels in groups A and B. Participant serum 25(OH)D levels at the end of the trial were positively correlated with those in intervention group A (4000 IU/day) (β=4.16, 95% CI 1.6 to 6.7, p=0.002), with food group consumption (β=0.95, 95% CI 0.01 to 1.89, p=0.047) and with baseline levels of serum 25(OH)D (β=0.43, 95% CI 0.29 to 0.58, p<0.0001).

CONCLUSION

The evidence provided in our study indicates that vitamin D supplementation of 4000 IU/day was more effective in reducing vitamin D deficiency among pregnant women and in improving serum 25(OH)D levels in mothers and their neonates compared with 2000 IU/day and 400 IU/day. Trial registration number NCT02215213.

Is Supplementation with Micronutrients Still Necessary during Pregnancy? A Review

INTRODUCTION

Proper nutrition during pregnancy is important to prevent nutritional imbalances that interfere with pregnancy. Micronutrients play critical roles in embryogenesis, fetal growth, and maternal health, as energy, protein, vitamin, and mineral needs can increase during pregnancy. Increased needs can be met by increasing the intake of dietary micronutrients. Severe micronutrient deficiency or excess during pregnancy can have negative effects on fetal growth (intrauterine growth retardation, low birth weight, or congenital malformations) and pregnancy development (pre-eclampsia or gestational diabetes). We investigate whether it is necessary to continue micronutrient supplementation during pregnancy to improve women's health in this stage and whether this supplementation could prevent and control pathologies associated with pregnancy.

AIM

The present review aims to summarize evidence on the effects of nutritional deficiencies on maternal and newborn morbidity.

METHODS

This aim is addressed by critically reviewing results from published studies on supplementation with different nutrients during pregnancy. For this, major scientific databases, scientific texts, and official webpages have been consulted. PubMed searches using the terms "pregnancy" OR "maternal-fetal health" AND "vitamins" OR "minerals" OR "supplementation" AND "requirement" OR "deficiency nutrients" were performed.

RESULTS

There are accepted interventions during pregnancy, such as folic acid supplementation to prevent congenital neural tube defects, potassium iodide supplementation to correct neurodevelopment, and oral iron supplementation during the second half of pregnancy to reduce the risk of maternal anemia and iron deficiency. A number of micronutrients have also been associated with pre-eclampsia, gestational diabetes mellitus, and nausea and vomiting in pregnancy. In general, experimental studies are necessary to demonstrate the benefits of supplementation with different micronutrients and to adjust the recommended daily doses and the recommended periconceptional nutrition for mothers.

CONCLUSIONS

Presently, there is evidence of the benefits of micronutrient supplementation in perinatal results, but indiscriminate use is discouraged due to the fact that the side effects of excessive doses are not known. Evidence supports the idea that micronutrient deficiencies negatively affect maternal health and the outcome of pregnancy. No single micronutrient is responsible for the adverse effects; thus, supplementing or correcting one deficiency will not be very effective while other deficiencies exist.

Exposome and foetoplacental vascular dysfunction in gestational diabetes mellitus

A balanced communication between the mother, placenta and foetus is crucial to reach a successful pregnancy. Several windows of exposure to environmental toxins are present during pregnancy. When the women metabolic status is affected by a disease or environmental toxin, the foetus is impacted and may result in altered development and growth. Gestational diabetes mellitus (GDM) is a disease of pregnancy characterised by abnormal glucose metabolism affecting the mother and foetus. This disease of pregnancy associates with postnatal consequences for the child and the mother. The whole endogenous and exogenous environmental factors is defined as the exposome. Endogenous insults conform to the endo-exposome, and disruptors contained in the immediate environment are the ecto-exposome. Some components of the endo-exposome, such as Selenium, vitamins D and B₁₂, adenosine, and a high-fat diet, and ecto-exposome, such as the heavy metals Arsenic, Mercury, Lead and Copper, and per- and polyfluoroakyl substances, result in adverse pregnancies, including an elevated risk of GDM or gestational diabesity. The impact of the exposome on the human placenta's vascular physiology and function in GDM and gestational diabesity is reviewed.

Ineffectiveness of antenatal guidance intervention for vitamin D insufficiency and deficiency in pregnant women in Kyoto, Japan

AIM

The aim of this study was to investigate the vitamin D status among healthy pregnant women in Japan, and to evaluate the effectiveness of the antenatal health guidance intervention for the pregnant women who were informed about their low vitamin D levels.

METHODS

We measured the level of 25-hydroxyvitamin D (25[OH]D) using chemiluminescent immunoassay among the singleton pregnant women who received at antenatal routine check-up (8-24 weeks of gestation) with written consent during September 2017-September 2018. The measurement values were informed by the concerned physician and health guidance intervention was given to the pregnant women with inadequate Vitamin D status (25[OH]D < 30 ng/mL). At around 36 weeks of gestation, the measurement of 25(OH)D and a questionnaire regarding behavioral changes after the guidance was conducted.

RESULTS

The average value of 25(OH)D of 1192 pregnant women before the guidance was 14.89 ± 4.85 ng/mL, and the prevalence of sufficient vitamin D status (25(OH)D ≥ 30 ng/mL) was 0.67% (8/1192). Nine hundred eighty-two pregnant women who had inadequate vitamin D status were followed, thereafter-guidance prevalence of sufficiency was 1.02% (10/982); insufficiency, 14.66% (144/982); and deficiency, 84.32% (828/982), respectively. Although the prevalence of deficiency was decreased after guidance intervention significantly, the prevalence was still high and the effect on behavioral changes was a little.

CONCLUSION

The prevalence of vitamin D sufficient status among pregnant women in Japan was extremely low, which is a serious condition. It was also revealed the effectiveness of the antenatal health guidance intervention for pregnant women was not enough.

Vitamin D Levels Correlate with Metabolic Syndrome Criteria in Algerian Patients: The Ex-vivo Immunomodulatory Effect of α, 25 Dihydroxyvitamin D3

BACKGROUND

Metabolic syndrome (MetS) is a combination of metabolic disorders with increased risks for several diseases, such as cardiovascular diseases and diabetes. It is associated with the presence of various inflammatory molecules. Vitamin D plays an important role in the regulation of metabolism homeostasis.

OBJECTIVE

The main goal of this work is to investigate vitamin D levels among Algerian MetS patients and its possible outcomes on key molecules of the immune response, as well, the immunomodulatory effects of its active metabolite.

METHODS

We evaluated vitamin D status by the electrochemiluminescence method, Nitric Oxide (NO) levels by the Griess method and Matrix Metalloproteinases (MMPs) activities such as MMP-2 and MMP-9 by zymography in plasma of patients and healthy controls (HC). The immunomodulatory effects of the active metabolite of vitamin D (α-25 (OH)2D3) on the production of NO, IL-6, IL-10, TGF- β and s-CTLA-4 were assessed by Griess method and ELISA, in peripheral blood mononuclear cells (PBMCs) of Algerian MetS patients and HC. MMPs activities were also determined ex-vivo, while iNOS expression was assessed by immunofluorescence staining.

RESULTS

Severe vitamin D deficiency was registered in Algerian MetS patients. The deficiency was found to be associated with an elevated in vivo NO production and high MMPs activity. Interestingly, α-25 (OH)2D3 declined the NO/iNOS system and IL-6 production, as well as MMPs activities. However, the ex-vivo production of IL-10, TGF-β increased in response to the treatment. We observed in the same way, the implication of s-CTLA-4 in MetS, which was markedly up-regulated with α-25 (OH)2D3.

CONCLUSION

Our report indicated the relationship between MetS factors and Vitamin D deficiency. The ex-vivo findings emphasize its impact on maintaining regulated immune balance.

Maternal vitamin D status and risk of gestational diabetes mellitus: A systematic review and meta-analysis of prospective cohort studies

BACKGROUND

No earlier systematic review and meta-analysis have been done on the association between maternal serum vitamin D status and risk of GDM among prospective studies. The current study was done to systematically review prospective cohort studies (with several years of follow-up) on the association between maternal serum vitamin D deficiency or insufficiency and risk of GDM.

METHODS

Relevant papers published up to January 2020 were searched through PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar using suitable keywords. All prospective cohort studies reporting Hazard Ratios (HRs) or Relative Risks (RRs) and 95% Confidence Intervals (CI) for GDM across categories of maternal serum vitamin D status were included.

RESULTS

A total of 29 prospective and nested case-control studies were included in the current systematic review, of which 27 studies had sufficient data for the meta-analysis. Individuals with vitamin D deficiency had a 26% greater risk of developing GDM than those with normal serum vitamin D concentrations (OR: 1.26; 95% CI: 1.13, 1.41). In addition, a significant positive association was seen between combined vitamin D insufficiency and deficiency and risk of developing GDM (OR: 1.23; 95% CI: 1.11, 1.35). Dose-response analysis showed a significant U-shaped non-linear association between serum vitamin D concentrations and risk of developing GDM (P < 0.001), such that those with serum vitamin D concentrations between 40 and 90 nmol/L had significantly reduced risk of GDM.

CONCLUSIONS

We found a significant association between vitamin D deficiency and an increased risk of GDM. The lowest risk of GDM was found among those with a serum vitamin D levels of 40-90 nmol/L. Further studies, including randomized clinical trials, are needed to confirm our findings.

REGISTRATION

PROSPERO (ID: 180722), https://www.crd.york.ac.uk/prospero/.

A case-control study to predict the risk of gestational diabetes mellitus by initial fasting blood sugar or past gestational history

BACKGROUND

Gestational diabetes mellitus (GDM) deserves proper prevention, diagnosis, and management due to healthcare implications from both maternal and fetal concerns.

OBJECTIVE

To evaluate the rate and investigate the risk factors for developing GDM.

MATERIALS AND METHODS

In this case-control, universal screening for GDM between 24 and 28 wk of gestation was performed in 613 pregnant women attending a prenatal clinic in Tehran who were followed-up until delivery between March 2017 to March 2018. Of the 613 women, 143 had GDM and 470 had normal glucose tolerance test as the primary diagnosis. Some GDM risk factors were compared in two groups.

RESULTS

Impaired glucose tolerance test was detected in 143 (23.3%) patients. Prevalence of GDM was higher in the first-trimester fasting blood sugar (FBS) > 90 qmg/dl group (p < 0.001). Comparison of the GDM and the normal glucose tolerance test groups demonstrated significant differences in maternal age, first-trimester FBS, third-trimester vitamin D level, maternal platelet count, maternal body mass index (BMI) (before 12 wk of gestation), weight gain during pregnancy, and the history of gestational complications in previous pregnancy (p < 0.01). In logistic regression, GDM was independently associated with older maternal age, higher first-trimester FBS, the history of gestational complications in previous pregnancy, lower third-trimester vitamin D level, and higher maternal platelet count (p < 0.01).

CONCLUSION

Both patients with higher initial FBS and the history of gestational complications in previous pregnancy should be considered high risk for GDM and screened earlier.

Dietary supplementation for gestational diabetes prevention and management: a meta-analysis of randomized controlled trials

PURPOSE

The use of supplement to prevent and ease gestational diabetes (GDM) progression has been examined in various studies, but the results were inconclusive, and studies evaluated dietary supplements separately. The present review aimed to evaluate the efficacy of various dietary supplementation on GDM risk and the surrogate markers for cardiometabolic risk of pregnant women with GDM.

METHODS

A comprehensive search on multiple databases were performed to identify randomized controlled trials. Random-effects model was used to pool the results in relative risk (RR) or mean difference.

RESULTS

Fifty-three randomized controlled studies with 9443 pregnant women were included. Vitamin D (5 studies, RR 0.64; 95% CI 0.44, 0.94) and myo-inositol (4 studies, RR 0.34, 95% CI 0.20, 0.58) supplementation significantly reduced the risk of GDM. Myo-inositol, probiotics, and vitamin D showed significant intervention effect on surrogate markers related to glycemic control, lipid profile, inflammatory, and oxidative stress. However, the majority of included studies were clustered to Iran and Italy, which might convey a generalizability bias.

CONCLUSION

Dietary supplementation including vitamin D and myoinositol supplementation has the potential in primary prevention and management of GDM, whereas probiotics demonstrated its ability in GDM management by improving the levels of surrogate markers for cardiometabolic risk. The potential for dietary supplement in preventing GDM or managing cardiometabolic risk of pregnant women should receive more attentions.

The relationship between maternal vitamin D deficiency and glycolipid metabolism and adverse pregnancy outcome

OBJECTIVE

Maternal vitamin D deficiency is associated with glucose and lipid metabolism in the mother and offspring. Meanwhile, it can also lead to adverse pregnancy outcomes. The aim of this case-control study was to document maternal, umbilical arterial glucose and lipid metabolic levels and correlations in pregnancies with or without vitamin D deficiency, while also investigating adverse pregnancy outcomes.

DESIGN/PARTICIPANTS/MEASUREMENTS

A total of 425 pregnant women who received antenatal care and delivered at Wenzhou People's Hospital were enrolled. According to their serum 25-hydroxyvitamin D [25(OH)D] level, the pregnant women were divided into the vitamin D deficiency group [25(OH)D < 20 ng/mL, 185 participants] and the control group [25(OH)D ≥ 20 ng/mL, 240 participants]. Maternal blood samples were collected at 24-28 weeks of gestation and delivery for 75-g oral glucose tolerance test (OGTT), and measurements of glucose and lipid metabolite levels and 25(OH)D levels. Umbilical arterial samples were collected during delivery (33.57-41.43 gestational weeks).

RESULTS

Compared with control participants, vitamin D deficiency women had significantly higher concentrations of fasting blood-glucose (P < .01), 1-h OGTT plasma glucose (P < .01), 2-h OGTT plasma glucose (P < .01), insulin (P < .01), HOMA-IR (P < .01), LDL (P < .01) and triglycerides (P = .02) and lower concentrations of HOMA-S (P < .01). Compared with the control group, vitamin D deficiency women had higher concentrations of triglycerides (P < .01) and lower concentrations of HDL-C (P < .01) and HOMA-β (P = .01) in infant umbilical arterial blood. Pearson's correlation analysis demonstrated that the maternal 25(OH)D level was negatively correlated with maternal plasma glucose, insulin, LDL-C, cholesterol, triglyceride and HOMA-IR (r = -.38, -.27, -.2, -.11, -.11, -.33 and .11; P < .01, <.01, <.01, <.05, <.05 and <.01, respectively), while there was a positive correlation between maternal serum 25(OH)D and HOMA-S (r = .11, P < .05). The triglyceride level in the umbilical artery was negatively correlated with maternal serum 25(OH)D concentration (r = -.286, P < .01), while the HDL-C and HOMA-β in umbilical artery were positively related (r = .154, .103, P < .01). Compared with the control group, the incidences of pre-eclampsia [4.8% (9/185) vs 1.25% (3/240), P = .03], gestational diabetes mellitus [19.45% (36/185) vs 12.08% (29/240), P = .04] and premature rupture of membranes [15.68% (29/185) vs 5.42% (13/240), P < .01] were higher in the vitamin D deficiency group.

CONCLUSION

Vitamin D deficiency during pregnancy is associated with maternal glucose and lipid metabolism and pregnancy outcomes. Therefore, it is worth recommending to maintain vitamin D status at an optimal level in pregnant women to prevent metabolic disorders and pregnancy complications.

Prevention and Management of Gestational Diabetes Using Vitamin D Supplementation: An Overview and Appraisal of Clinical Trials

A number of studies have examined the role of vitamin D in reproductive processes and disorders of pregnancy such as gestational diabetes mellitus (GDM). Although observational studies have linked maternal vitamin D deficiency with a plethora of adverse pregnancy outcomes including GDM, intervention trials generally do not support the use of vitamin D supplementation for GDM prevention or management. This narrative review provides an up-to-date overview and critical appraisal of randomised controlled trials (RCTs) to describe the current state of knowledge regarding the efficacy of vitamin D supplementation for preventing and/or managing GDM. Overall, although RCT data indicates a potential benefit of vitamin D in maternal glycaemic control, results are highly disparate and the data published to date have not conclusively established the efficacy of vitamin D in GDM prevention. There are, however, several limitations within the existing literature, including some considerable challenges that are unique to vitamin D trials, which should be carefully considered in the interpretation of the evidence and design of future studies. For now, many unanswered questions remain, and there is still a need for adequately powered and well-designed trials before routine supplementation can be recommended in the context of GDM.

Understanding the Biological Activities of Vitamin D in Type 1 Neurofibromatosis: New Insights into Disease Pathogenesis and Therapeutic Design

Vitamin D is a fat-soluble steroid hormone playing a pivotal role in calcium and phosphate homeostasis as well as in bone health. Vitamin D levels are not exclusively dependent on food intake. Indeed, the endogenous production-occurring in the skin and dependent on sun exposure-contributes to the majority amount of vitamin D present in the body. Since vitamin D receptors (VDRs) are ubiquitous and drive the expression of hundreds of genes, the interest in vitamin D has tremendously grown and its role in different diseases has been extensively studied. Several investigations indicated that vitamin D action extends far beyond bone health and calcium metabolism, showing broad effects on a variety of critical illnesses, including cancer, infections, cardiovascular and autoimmune diseases. Epidemiological studies indicated that low circulating vitamin D levels inversely correlate with cutaneous manifestations and bone abnormalities, clinical hallmarks of neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant tumour predisposition syndrome causing significant pain and morbidity, for which limited treatment options are available. In this context, vitamin D or its analogues have been used to treat both skin and bone lesions in NF1 patients, alone or combined with other therapeutic agents. Here we provide an overview of vitamin D, its characteristic nutritional properties relevant for health benefits and its role in NF1 disorder. We focus on preclinical and clinical studies that demonstrated the clinical correlation between vitamin D status and NF1 disease, thus providing important insights into disease pathogenesis and new opportunities for targeted therapy.

Changes in vitamin D status considering hemodilution factors in Japanese pregnant women according to trimester: A longitudinal survey

Objectives

There have been no longitudinal surveys on the changes in 25-hydroxyvitamin D [25(OH)D] while considering hemodilution factors among pregnant Japanese women. Therefore, we examined 25(OH)D levels as well as red blood cell count (RBC), hemoglobin (Hb), and Hematocrit (Hct) at the three trimesters among pregnant Japanese women to determine the distribution of serum 25(OH)D levels and the influence of hemodilution.

Design

This was a longitudinal study.

Setting

The study was conducted at Ibaraki Seinan Medical Center Hospital in Japan.

Participants

The participants comprised 50 women in the first trimester with singleton pregnancies and without any complications.

Outcome measures

Participants were recruited from June to August 2018, and followed up till their postpartum period. Blood samples were collected at the first, second, and third trimesters, i.e., at 4–15, 16–27, and 28–39 weeks, respectively. 25(OH)D levels, RBC, Hb, and Hct were analyzed across the three trimesters.

Results

Comparing the first, second, and third trimesters, 25(OH)D, RBC, and Hb were significantly declined in the second and third trimesters (p < 0.001). According to Spearman’s correlation coefficient with 25(OH)D and RCB, Hb, Hct, significant correlations were found between 25(OH)D and Hb (p < 0.001), as well as Hct (p < 0.001) in the third trimester.

Conclusions

The present study had two major findings. First, it showed that the vitamin D status of most pregnant Japanese women were considered as vitamin D deficient. Second, the maternal serum 25(OH)D levels, RBC, Hb, and Hct of the pregnant women declined in the second and third trimesters. Thus we propose to have routine screening of vitamin D status of pregnant women, especially in the second trimester.

Circulating vitamin D and the risk of gestational diabetes: a systematic review and dose-response meta-analysis

PURPOSE

Several meta-analyses of observational studies revealed a modest increase in the risk of gestational diabetes (GDM) among pregnant women with low levels of serum vitamin D. However, no study examined a dose-response meta-analysis as well as a high versus low analysis in this regard.

METHODS

We systematically searched PubMed, Embase, ISI Web of Science, and Scopus up to August 2019 to find prospective observational studies investigating the association of serum 25(OH)D with the risk of developing GDM. Using a random-effects model, the reported risk estimates were pooled.

RESULTS

Nine cohort studies and six nested case-control studies were included in the final analysis (40,788 participants and 1848 cases). Considering linear analysis, each 10 nmol/L increase in circulating 25(OH)D was associated with a 2% lower risk of GDM (effect size (ES): 0.98; 95% CI: 0.98, 0.99; I² = 85.0%, P < 0.001). highest compared with the lowest category of circulating 25(OH)D was associated with a 29% lower risk of GDM, with low evidence of heterogeneity (I² = 45.0%, P = 0.079).

CONCLUSIONS

In conclusion, lower levels of serum 25(OH)D were associated with a higher chance of GDM. Differential results existed between the overall and subgroup analysis, either based on vitamin D detection methods or based on maternal age, although these subgroups partially lowered the heterogeneity.

The Effect of Dietary Intake of Vitamin D on Gestational Diabetes Mellitus

Diabetes mellitus (DM) is a growing health issue that has been reaching epidemic proportions in the recent years. Low intake of some nutrients like vitamin D may increase the risk of gestational diabetes mellitus (GDM). This study was to investigate the association between the dietary intake of Vitamin D and GDM among women in the Eastern Region of Saudi Arabia. A case-control study was conducted in a sample of 121 women, among those 72 were with GDM and 49 were controls. Vitamin D was estimated using food frequency questionnaire. Also, the 24-h’s dietary recall was carried out for 3 days to determine the nutrient intake as well as biochemical analysis for blood glucose level. In this study, GDM subjects were consuming significantly more eggs (P = .040). Vitamin D and vitamin C intakes in GDM and control pregnant women were lower than recommended dietary allowances (RDA). It was also found that low-fat milk, full-fat milk, fortified yogurt, and fortified orange juice were significantly associated with GDM (P < 0.05). Saudi women with GDM need a well-organized dietary counseling before, during pregnancy, and after delivery especially for vitamin D sources.

How 25(OH)D Levels during Pregnancy Affect Prevalence of Autism in Children: Systematic Review

Autism spectrum disorder (ASD) is a group of dysfunctions in social interaction, communication, and behaviors. The etiology of ASD is not yet fully understood; however, it consists of the interaction between genetics and the environment. An increasing amount of evidence points to the possibility that gestational and early-childhood vitamin D deficiency may be involved in the etiology of some cases of ASD. Herein, we systematically review the literature for studies on vitamin D status during pregnancy and ASD outcomes. Forty-three studies in the PubMed and 124 studies in EMBASE databases were initially found. After screening, 26 were identified as candidate studies for inclusion. Finally, 14 articles met the inclusion criteria, which originated from nine countries. The studies included 10 original research studies and four review studies conducted between 2012 and 2020. The strength of evidence that vitamin D levels during pregnancy increase the risk of developing autism is very low. This is because the evidence relies exclusively on observational studies that did not equally consider all important confounders and that assessed the indirect relationship between vitamin D as a surrogate for sunlight exposure and autism risk. The findings of this systematic review are consistent with the hypothesis that low vitamin D levels might contribute to the development of autism. However, we must also recognize the possible confusion bias and therefore experimental studies with very large sample sizes, given incidence of autism, that allow us to detect blood levels in pregnant women would be helpful to clarify this point.

Relationship between vitamin D status in the first trimester of pregnancy and gestational diabetes mellitus - A nested case-control study

BACKGROUND & AIMS

Gestational diabetes mellitus (GDM) is one of the most frequent medical complications during pregnancy. It has been associated with many adverse pregnancy, fetal and neonatal outcomes, as well as with an increased risk for mothers and children in the long term. There is a growing interest in vitamin D and its potential role in the development of metabolic disorders. However, the medical literature is not consensual. The aim of this study was to assess the risk of GDM according to vitamin D status during the first trimester.

METHODS

This study is a nested case-control study performed from a multicenter prospective observational cohort of pregnant women assessed for 25-hydroxyvitamin D levels (25OHD). Three hundred ninety-three patients were included in the initial cohort. After applying exclusion criteria, a total of 1191 pregnant women were included. Two hundred fifty women with GDM (cases) were matched to 941 women without GDM (controls) for parity, age, body mass index before pregnancy, the season of conception, and phototype. This study was funded by a grant from the "Programme Hospitalier de Recherche Publique 2010".

RESULTS

The GDM risk was significantly greater for patients with 25OHD levels <20 ng/mL (OR = 1∙42, 95% CI 1∙06-1∙91; p = 0∙021). However, there was no significant relationship with other thresholds. The study of 25OHD levels with the more precise cutting of 5 units intervals showed a variable relationship with GDM risk, as the risk was low for very low 25OHD levels, increased for moderated levels, decreased for normal levels, and finally increased for higher levels.

CONCLUSION

According to our study, there seems to be no linear relationship between GDM and 25OHD levels in the first trimester of pregnancy since GDM risk does not continuously decrease as 25OHD concentrations increase. Our results most probably highlight the absence of an association between 25OHD levels and GDM risk.

Vitamin D Deficiency and Autism Spectrum Disorder

Vitamin D is a neurosteroid hormone crucially involved in neurodevelopment. Neural cell proliferation, neurotransmission, oxidative stress and immune function represent the main mechanisms mediated by vitamin D in the Central Nervous System. Therefore, its deficiency during pregnancy and early childhood may significantly impact on a developing brain, leading to possible adverse neuropsychological outcomes including Autism Spectrum Disorder (ASD). Significant vitamin D deficiency is described within children affected by ASD and in pregnant mothers whose offspring will later develop ASD, suggesting a possible role of the hormone as a contributing risk factor in the etiopathogenesis of ASD. We reviewed the actual literature on the potential contributing role of prenatal and early postnatal vitamin D deficiency in ASD etiopathogenesis, at both genetic and environmental levels, and the possible effect of vitamin D supplementation in autistic children. Conflicting but promising results emerged on the topic. Further Randomized Controlled Trials studies carried out during pregnancy and early infancy are necessary for better understanding the possible contribution of vitamin D deficiency in the etiopathogenesis of autism and the potential efficacy of the hormone supplementation in the improvement of ASD core symptoms.

Seasonal variations in incidence and maternal-fetal outcomes of gestational diabetes

AIMS

To determine whether the neonatal and delivery outcomes of gestational diabetes vary seasonally in the context of a relatively cool temperate climate.

METHODS

A retrospect cohort of 23 735 women consecutively delivering singleton, live-born term infants in a single tertiary obstetrics centre in the UK (2004-2008) was identified. A total of 985 (4.1%) met the diagnostic criteria for gestational diabetes. Additive dynamic regression models, adjusted for maternal age, BMI, parity and ethnicity, were used to compare gestational diabetes incidence and outcomes over annual cycles. Outcomes included: random plasma glucose at booking; gestational diabetes diagnosis; birth weight centile; and delivery mode.

RESULTS

The incidence of gestational diabetes varied by 30% from peak incidence (October births) to lowest incidence (March births; P=0.031). Ambient temperature at time of testing (28 weeks) was strongly positively associated with diagnosis (P<0.001). Significant seasonal variation was evident in birth weight in gestational diabetes-affected pregnancies (average 54^th centile June to September; average 60^th centile December to March; P=0.027). Emergency Caesarean rates also showed significant seasonal variation of up to 50% (P=0.038), which was closely temporally correlated with increased birth weights.

CONCLUSIONS

There is substantial seasonal variation in gestational diabetes incidence and maternal-fetal outcomes, even in a relatively cool temperate climate. The highest average birth weight and greatest risk of emergency Caesarean delivery occurs in women delivering during the spring months. Recognizing seasonal variation in neonatal and delivery outcomes provides new opportunity for individualizing approaches to managing gestational diabetes.

Vitamin D Deficiency at Mid-Pregnancy Is Associated with a Higher Risk of Postpartum Glucose Intolerance in Women with Gestational Diabetes Mellitus

BACKGROUND

To evaluate the association between serum 25-hydroxyvitamin D (25(OH)D) at mid-pregnancy and postpartum glucose intolerance in women with gestational diabetes mellitus (GDM).

METHODS

We enrolled 348 pregnant women diagnosed with GDM from August 2012 to October 2016. We measured serum 25(OH)D levels at mid-pregnancy and carried out a 75-g oral glucose tolerance test at 6 to 12 weeks after delivery. Vitamin D deficiency was defined as serum 25(OH)D <20 ng/mL.

RESULTS

The prevalence of vitamin D deficiency was 76.7% (n=267). Women with vitamin D deficiency had a higher prevalence of postpartum glucose intolerance than did those without vitamin D deficiency (48.7% vs. 32.1%, P=0.011). Serum 25(OH)D level was negatively correlated with hemoglobin A1c at antepartum and postpartum period (antepartum: r=-0.186, P=0.001; postpartum: r=-0.129, P=0.047). Homeostasis model assessment of β-cell function was positively correlated with serum 25(OH)D level only postpartum (r=0.138, P=0.035). The risk of postpartum glucose intolerance was 2.00 times (95% confidence interval, 1.13 to 3.55) higher in women with vitamin D deficiency than in those without vitamin D deficiency (P=0.018).

CONCLUSION

In women with GDM, vitamin D deficiency at mid-pregnancy is associated with an elevated risk of postpartum glucose intolerance.

Serum vitamin D deficiency and risk of gestational diabetes mellitus: a meta-analysis

INTRODUCTION

This meta-analysis was performed to confirm the relationship of gestational diabetes mellitus (GDM) and vitamin D.

MATERIAL AND METHODS

PubMed and CNKI databases were searched for relevant articles. Standard mean difference (SMD) along with 95% CI was used to compare vitamin D level between women with GDM and healthy subjects. The correlation coefficient between the vitamin D and homeostasis model assessment-insulin resistance index (HOMA-IR) was analyzed.

RESULTS

The vitamin D level of GDM subjects was much lower than healthy subjects (SMD = -0.71, 95% CI: -0.91, -0.50). Vitamin D deficiency was associated with high risk of GDM (OR = 1.15, 95% CI: 1.07-1.23). Vitamin D was negatively correlated with HOMA-IR (r = -0.62, 95% CI: -0.85, -0.39). The analysis showed no publication bias (Egger's: p = 0.197; Begg's: p = 0.786).

CONCLUSIONS

Vitamin D is closely associated with the onset of GDM.

Calcifediol Decreases Interleukin-6 Secretion by Cultured Human Trophoblasts From GDM Pregnancies

Gestational diabetes mellitus (GDM) is often characterized by low maternal calcifediol (25OHD) and high inflammation levels. This study aimed to determine whether placental protein expressions of CYP27B1, vitamin D receptor (VDR), and CYP24A1 are impaired in GDM and to investigate the effect of a 25OHD treatment on IL-6 secretion by GDM trophoblasts compared with normoglycemic (NG) trophoblasts. Placental tissue samples were harvested to determine protein expression of CYP27B1, VDR, and CYP24A1 by immunoblots. Isolated trophoblasts were stimulated with 25OHD concentrations (25 to 2000 nM) once a day for 3 days and IL-6 secretion was quantified (ELISA). We recruited 17 NG women, 19 women with GDM treated with diet and exercise alone (GDM-d) and 9 women with GDM who necessitated insulin therapy (GDM-i). Protein expressions of CYP27B1 and VDR were significantly higher in placental tissue from GDM-d women compared with NG women (both P = 0.02), whereas no differences were detected between GDM-i and NG placental tissues. In cultured trophoblasts (two groups; n = 5 NG and n = 5 GDM-d), exposure to increasing 25OHD concentrations significantly decreased IL-6 secretion in the GDM-d group only (P = 0.006). After treatment with 25OHD (2000 nM), IL-6 secretion was lower in the GDM-d group compared with the NG group (P = 0.03). Our results suggest an upregulation of the VDR-1,25(OH)2D complex bioavailability in GDM-d placentas, possibly reflecting a compensatory mechanism aiming to ensure that vitamin D can exert its genomic and nongenomic effects in the target cells of the placental-fetal unit. Our findings support an anti-inflammatory effect of vitamin D at the feto-maternal interface in GDM-d pregnancies.