Maternal vitamin D deficiency during pregnancy and low birth weight: a systematic review and meta-analysis

Maternal metabolomics linking prenatal exposure to fine particulate matter and birth weight: a cross-sectional analysis of the MADRES cohort

BACKGROUND

Prenatal exposure to air pollution has been associated with an increased risk of low birth weight. Disrupted metabolism may serve as an underlying mechanism, but the specific metabolic pathways involved remain unclear.

METHODS

In the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) study, 382 third-trimester maternal serum samples were analyzed for untargeted metabolomics using liquid chromatography with Fourier transform high-resolution mass spectrometry. Ambient concentrations of fine particulate matter (PM2.5), particulate matter ≤ 10 μm in diameter (PM10), nitrogen dioxide (NO2), and ozone (O3) were estimated using inverse-distance-squared weighted spatial interpolation based on daily residential histories. Birth weight was retrieved from medical records. Linear regression identified metabolomic features associated with air pollution exposure or birth weight, followed by Mummichog pathway enrichment and mediation analyses for the selected features.

RESULTS

Second-trimester PM2.5 exposure was associated with lower birth weight. Fourteen metabolic pathways were significantly associated with second-trimester PM2.5 exposure, with C21-steroid hormone biosynthesis and metabolism showing the most significant association. Sixteen metabolic pathways were significantly associated with birth weight, with vitamin A (retinol) metabolism being the most significantly enriched pathway. Seven pathways were associated with both PM2.5 exposure and birth weight, including C21-steroid hormone biosynthesis and metabolism, bile acid biosynthesis, tyrosine metabolism, ascorbate (vitamin C) and aldarate metabolism, vitamin D3 (cholecalciferol) metabolism, vitamin A (retinol) metabolism, and pyrimidine metabolism. Overweight or obese women exhibited more metabolomic features and metabolic pathways associated with PM2.5 exposure compared to underweight or normal-weight women. No associations were observed between PM10, NO2, or O3 and birth weight.

CONCLUSIONS

Maternal metabolic pathways involving steroid metabolism, oxidative stress and inflammation, vitamin metabolism, and DNA damage may link prenatal PM2.5 exposure to lower birth weight, with overweight or obese women potentially more susceptible to these metabolic disruptions.

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.

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.

Vitamin D supplementation for women during pregnancy

BACKGROUND

Vitamin D supplementation during pregnancy may help improve maternal and neonatal health outcomes (such as fewer preterm birth and low birthweight babies) and reduce the risk of adverse pregnancy outcomes (such as severe postpartum haemorrhage).

OBJECTIVES

To examine whether vitamin D supplementation alone or in combination with calcium or other vitamins and minerals given to women during pregnancy can safely improve certain maternal and neonatal outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Trials Register (which includes results of comprehensive searches of CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform, and relevant conference proceedings) (3 December 2022). We also searched the reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised trials evaluating the effect of supplementation with vitamin D alone or in combination with other micronutrients for women during pregnancy in comparison to placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently i) assessed the eligibility of studies against the inclusion criteria, ii) assessed trustworthiness based on pre-defined criteria of scientific integrity, iii) extracted data from included studies, and iv) assessed the risk of bias of the included studies. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

The previous version of this review included 30 studies; in this update, we have removed 20 of these studies to 'awaiting classification' following assessments of trustworthiness, one study has been excluded, and one new study included. This current review has a total of 10 included studies, 117 excluded studies, 34 studies in awaiting assessment, and seven ongoing studies. We used the GRADE approach to assess the certainty of the evidence. This removal of the studies resulted in evidence that was downgraded to low-certainty or very low-certainty due to study design limitations, inconsistency between studies, and imprecision. Supplementation with vitamin D compared to no intervention or a placebo A total of eight studies involving 2313 pregnant women were included in this comparison. We assessed four studies as having a low risk of bias for most domains and four studies as having high risk or unclear risk of bias for most domains. The evidence is very uncertain about the effect of supplementation with vitamin D during pregnancy compared to placebo or no intervention on pre-eclampsia (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.21 to 1.33; 1 study, 165 women), gestational diabetes (RR 0.53, 95% CI 0.03 to 8.28; 1 study, 165 women), preterm birth (< 37 weeks) (RR 0.76, 95% CI 0.25 to 2.33; 3 studies, 1368 women), nephritic syndrome (RR 0.17, 95% CI 0.01 to 4.06; 1 study, 135 women), or hypercalcaemia (1 study; no cases reported). Supplementation with vitamin D during pregnancy may reduce the risk of severe postpartum haemorrhage; however, only one study reported this outcome (RR 0.68, 95% CI 0.51 to 0.91; 1 study, 1134 women; low-certainty evidence) and may reduce the risk of low birthweight; however, the upper CI suggests that an increase in risk cannot be ruled out (RR 0.69, 95% CI 0.44 to 1.08; 3 studies, 371 infants; low-certainty evidence). Supplementation with vitamin D + calcium compared to no intervention or a placebo One study involving 84 pregnant women was included in this comparison. Overall, this study was at moderate to high risk of bias. Pre-eclampsia, gestational diabetes, and maternal adverse events were not reported. The evidence is very uncertain about the effect of supplementation with vitamin D and calcium on preterm birth (RR not estimable; very low-certainty evidence) or for low birthweight (RR 1.45, 95% CI 0.14 to 14.94; very low-certainty evidence) compared to women who received placebo or no intervention. Supplementation with vitamin D + calcium + other vitamins and minerals versus calcium + other vitamins and minerals (but no vitamin D) One study involving 1298 pregnant women was included in this comparison. We assessed this study as having a low risk of bias in all domains. Pre-eclampsia was not reported. The evidence is very uncertain about the effect of supplementation with vitamin D, calcium, and other vitamins and minerals during pregnancy compared to no vitamin D on gestational diabetes (RR 0.42, 95% CI 0.10 to 1.73; very low-certainty evidence), maternal adverse events (hypercalcaemia no events and hypercalciuria RR 0.25, 95% CI 0.02 to 3.97; very low-certainty evidence), preterm birth (RR 1.04, 95% CI 0.68 to 1.59; low-certainty evidence), or low birthweight (RR 1.12, 95% CI 0.82 to 1.51; low-certainty evidence).

AUTHORS' CONCLUSIONS

This updated review using the trustworthy assessment tool removed 21 studies from the previous update and added one new study for a total of 10 included studies. In this setting, supplementation with vitamin D alone compared to no intervention or a placebo resulted in very uncertain evidence on pre-eclampsia, gestational diabetes, preterm birth, or nephritic syndrome. It may reduce the risk of severe postpartum haemorrhage; however, only one study reported this outcome. It may also reduce the risk of low birthweight; however, the upper CI suggests that an increase in risk cannot be ruled out. Supplementation with vitamin D and calcium versus placebo or no intervention resulted in very uncertain evidence on preterm birth and low birthweight. Pre-eclampsia, gestational diabetes, and maternal adverse events were not reported in the only study included in this comparison. Supplementation with vitamin D + calcium + other vitamins and minerals versus calcium + other vitamins and minerals (but no vitamin D) resulted in very uncertain evidence on gestational diabetes and maternal adverse events (hypercalciuria) and uncertain evidence on preterm birth and low birthweight. Pre-eclampsia was not reported in the only study included in this comparison. All findings warrant further research. Additional rigorous, high-quality, and larger randomised trials are required to evaluate the effects of vitamin D supplementation in pregnancy, particularly in relation to the risk of maternal adverse events.

Low levels of Vitamin D during pregnancy associated with gestational diabetes mellitus and low birth weight: results from the MAASTHI birth cohort

Introduction

India has a high prevalence of Vitamin D insufficiency among women of childbearing age. In this study, we aimed to evaluate the potential relationship between Vitamin D deficiency and gestational diabetes mellitus (GDM) and low birth weight (LBW) of newborns in the "Maternal antecedents of adiposity and studying the transgenerational role of hyperglycaemia and insulin" (MAASTHI) birth cohort.

Methods

A prospective cohort study involving 230 participants was conducted in public hospitals located in urban Bengaluru, India. Healthy pregnant women who visited these hospitals for antenatal care (ANC) and who were between 14 and 36 weeks of gestational age were recruited after obtaining their informed consent. An oral glucose tolerance test (OGTT) was administered between 24 and 36 weeks of pregnancy and blood samples were preserved at -80°C for Vitamin D analysis. Follow-up at birth included recording the child's birth weight.

Results

We found that 178 (77.4%) of the study participants were vitamin D deficient, 44 (19.1%) were diagnosed with GDM, and 64 (27.8%) gave birth to LBW babies. Women in the lowest quartile of serum Vitamin D levels had three times higher odds of developing GDM than women in the higher quartiles [OR = 3.22 (95% CI: 1.03, 10.07), p = 0.04] after adjusting for age, parity, socioeconomic status, season, and adiposity. For every one-unit increase in Vitamin D levels, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) decreased by nearly 18%. Furthermore, causal mediation analysis showed that a decrease in one unit of Vitamin D is associated with a decrease of 0.015 units of fasting blood sugar (FBS) and 0.019 units of postprandial blood sugar (PPBS) as it flows through the mediator variable insulin resistance. Vitamin D-deficient women were twice at risk of giving birth to LBW babies (OR 2.04, 95% CI 0.99, 4.19, p = 0.05).

Discussions

Low levels of Vitamin D during pregnancy are associated with a greater risk of pregnant women developing GDM and giving birth to LBW babies in urban Bengaluru.

Effects of vitamin D in pregnancy on maternal and offspring health-related outcomes: An umbrella review of systematic review and meta-analyses

BACKGROUND

Vitamin D deficiency has been linked with several adverse maternal and fetal outcomes.

OBJECTIVE

To summarize systematic reviews and meta-analyses evaluating the effects of vitamin D deficiency and of vitamin D supplementation in pregnancy on maternal and offspring health-related outcomes.

METHODS

Prior to conducting this umbrella review, we registered the protocol in PROSPERO (CRD42022368003). We conducted searches in PubMed, Embase, and Cochrane Library for systematic reviews and meta-analyses on vitamin D in pregnancy, from database inception to October 2, 2023. All outcomes related to vitamin D in pregnancy obtained from the systematic reviews and meta-analyses were extracted.

DATA EXTRACTION

Two reviewers independently chose studies and collected information on health outcomes. The quality of the included articles' methodology was assessed using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews-2).

RESULTS

We identified 16 eligible systematic reviews and meta-analyses, which included 250,569 women. Our results demonstrated that vitamin D deficiency in pregnancy is associated with increased risk of preterm birth, small-for gestational age/low birth weight infants, recurrent miscarriage, bacterial vaginosis and gestational diabetes mellitus. Vitamin D supplementation in pregnancy increases birth weight, and reduces the risk of maternal pre-eclampsia, miscarriage, and vitamin D deficiency, fetal or neonatal mortality, as well as attention-deficit hyperactivity disorder, and autism spectrum disorder in childhood. In women with gestational diabetes mellitus, vitamin D supplementation in pregnancy can reduce the risk of maternal hyperbilirubinemia, polyhydramnios, macrosomia, fetal distress, and neonatal hospitalization.

CONCLUSION

Due to the association with adverse maternal and offspring health outcomes, we recommend the vitamin D status in pregnancy should be monitored, particularly in women at high risk of vitamin D deficiency. It is suggested that pregnant women take a dose of >400 IU/day of vitamin D supplementation during pregnancy to prevent certain adverse outcomes.

Post Hoc Analysis of National Institute of Child Health and Human Development Vitamin-D Pregnancy Cohort and The Role of Functional Vitamin-D Deficiency in Pregnancy

OBJECTIVE

Our objective was to conduct a secondary, post hoc analysis of the National Institute of Child Health and Human Development (NICHD) vitamin D (vitD) pregnancy study by Hollis et al, which reported on the effect of vitD supplementation in pregnant women and determine the potential interaction between intact parathyroid hormone (iPTH) concentrations, vitD status, and various comorbidities associated with pregnancy. Women with low 25-hydroxy vitamin D (25(OH)D) concentrations and high iPTH concentrations during pregnancy, known as functional vitamin-D deficiency (FVDD), were more likely to acquire complications also affecting their neonates.

STUDY DESIGN

This post hoc analysis of data collected from a diverse group of pregnant women participating in the NICHD vitD pregnancy study was applied to investigate the applicability of the concept of FVDD in pregnancy (Hemmingway, 2018) in identifying potential risks for certain comorbidities of pregnancy. This analysis defines FVDD as maternal serum 25(OH)D concentrations below 20 ng/mL and iPTH concentrations above 65 pg/mL creating a definitive ratio number, 0.308, to classify mothers as having FVDD prior to delivery (PTD). Statistical analyses were performed using SAS 9.4 (Cary, NC).

RESULTS

In total, 281 women (85 African American, 115 Hispanic, and 81 Caucasian) with 25(OH)D and iPTH concentrations measured at monthly visits were included in this analysis. No statistically significant association was found between mothers classified as having FVDD at baseline or 1-month PTD and hypertensive disorders of pregnancy, infection, or admittance to the neonatal intensive care unit. When combining all comorbidities of pregnancy in this cohort, results showed those with FVDD at baseline, 24 weeks' gestation, and 1-month PTD were more likely to experience a comorbidity (p = 0.001; p = 0.001; p = 0.004, respectively). Those with FVDD 1-month PTD were 7.1 times (confidence interval [CI]: 1.71-29.81) more likely to have preterm birth (<37 weeks) than women without FVDD.

CONCLUSION

Participants were more likely to have experienced preterm birth if they met the criteria for FVDD. This study supports the importance of FVDD during pregnancy.

KEY POINTS

· Functional vitamin D deficiency (FVDD) is defined as the ratio of 25(OH)D divided by iPTH concentration ≤0.308.. · At a minimum, it is recommended that vitamin D status be kept in the healthy range based on current recommendations for pregnant individuals.. · FVDD is a more sensitive predictor of pregnancy risk than 25(OH)D alone.. · FVDD identified those with greater risk of preterm birth in this cohort..

"You are my sunshine, my only sunshine": maternal vitamin D status and supplementation in pregnancy and their effect on neonatal and childhood outcomes

Vitamin D (VD) plays a crucial role in regulating calcium homeostasis, while the wealth of its pleiotropic actions is gaining increasing research interest. Sufficient VD concentrations are of clinical relevance, particularly in the context of physiological alterations, such as those occurring during pregnancy when maternal VD is the sole source for the developing fetus. As a result, inadequate VD concentrations in pregnancy have been associated with perinatal complications and adverse neonatal outcomes, including preeclampsia, gestational diabetes mellitus, increased rates of cesarean section, low birth weight, small-for-gestational-age infants, poor immune and skeletal growth, allergies, and respiratory infections. Over the past few decades, several observational studies have underlined the important role of maternal VD in the neural, musculoskeletal, and psychomotor growth and bone health of the offspring. However, the complexity of the factors involved in regulating and assessing VD homeostasis, including race, sun exposure, dietary habits, and laboratory measurement techniques, makes the interpretation of relevant research findings challenging. The aim of this narrative review is to summarize the evidence on the importance of VD in maintaining optimal health during pregnancy, infancy, childhood, and adolescence.

The association between umbilical cord blood fat-soluble vitamin concentrations and infant birth weight

Background

Fat-soluble vitamins, including vitamins A, D and E, play an important role in the regulation of glucose and lipid metabolism, and may affect infant birth weight. Evidence on the association of birthweight with fat-soluble vitamins is controversial. Therefore, this study aims is to determine the associations of birthweight with vitamin A, D, and E concentrations in cord blood.

Methods

A total of 199 mother-infant pairs were enrolled in the study. According to gestational age and birth weight, the mother-infant pairs were divided into small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA). The Vitamin A, D, and E concentrations in serum were measured by high-performance liquid chromatography tandem-mass spectrometry.

Results

The concentrations of vitamin A in the SGA group were significantly lower than those in the AGA and LGA groups. The concentrations of vitamin E in the SGA group were significantly higher than those in the AGA and LGA groups. However, no significant differences were observed in vitamin D among the three groups. Being male (β = 0.317, p < 0.001) and birth weight (β = 0.229, p = 0.014) were positively correlated with the levels of vitamin A. Birth weight (β = -0.213, p= 0.026) was correlated with lower levels of vitamin E. No correlation was found between influencing Factors and the levels of vitamin D (p> 0.05). After adjusting for gestational age, sex, mother's age, delivery mode, pre-pregnancy BMI, and weight gain during pregnancy, the levels of cord blood vitamin A were positively correlated with birth weight (p=0.012).

Conclusion

The infant's birth weight is associated with the levels of cord blood vitamins A and E. The dysregulation of vitamins A and E in infants may be a risk factor for fetal growth and future metabolic diseases.

The effect of maternal vitamin D deficiency during pregnancy on glycolipid metabolism of offspring rats and the improvement of vitamin D intervention after weaning

Background

Vitamin D deficiency during pregnancy is common, but whether maternal vitamin D status affects glycolipid metabolism of offspring remains unclear.

Objective

To evaluate the effect of maternal vitamin D deficiency during pregnancy on the glycolipid metabolism of offspring at different life-cycles (from birth to adulthood) and to explore the improvement of different dosages of vitamin D supplementation.

Methods

Sprague-Dawley rats were fed vitamin D-deprived (VDD group) or standard vitamin D diets (SC group) during pregnancy, and their diets were changed to standard vitamin D diets during lactation (the offspring were sorted into VDDoffspring and SCoffspring groups). After weaning, rats in the VDDoffspring group were randomly assigned to the VDDoffspring, VDDoffspring-S3300 and VDDoffspring-S10000 groups with diets containing standard, medium and high dosages of vitamin D for 12 wk. Serum was collected for biochemical analyses at postnatal Day 21, postnatal Day 56 and postnatal Day 84. Oral glucose tolerance test (OGTT) was performed at postnatal Day 70.

Results

Compared to SCoffspring, rats in the VDDoffspring group had significantly lower birth weight with faster weight gain and higher levels of lipid metabolism in early life. After near adulthood, the differences in weight and lipid metabolism between the two groups disappeared. OGTT showed significantly higher blood glucose levels in the VDDoffspring group at 30 min, 60 min, and 90 min. The continuation of vitamin D supplementation at medium and high dosages after weaning did not cause any obvious changes in weight or glycolipid metabolism (except for postprandial hyperglycemia). OGTT demonstrated that the glucose levels in the VDDoffspring-S3300 group were lowest at all the time points and that those in the VDDoffspring-S10000 group were the highest at 30 min, 60 min, and 90 min among the three groups.

Conclusion

The adverse effects of vitamin D deficiency during pregnancy on glycolipid metabolism in offspring vary in different stages. Over a long time period, adequate vitamin D supplementation is beneficial to glycolipid metabolism for the offspring of subjects with vitamin D deficiency during pregnancy; however, further improvement is required.

Embryonic vitamin D deficiency programs hematopoietic stem cells to induce type 2 diabetes

Environmental factors may alter the fetal genome to cause metabolic diseases. It is unknown whether embryonic immune cell programming impacts the risk of type 2 diabetes in later life. We demonstrate that transplantation of fetal hematopoietic stem cells (HSCs) made vitamin D deficient in utero induce diabetes in vitamin D-sufficient mice. Vitamin D deficiency epigenetically suppresses Jarid2 expression and activates the Mef2/PGC1a pathway in HSCs, which persists in recipient bone marrow, resulting in adipose macrophage infiltration. These macrophages secrete miR106-5p, which promotes adipose insulin resistance by repressing PIK3 catalytic and regulatory subunits and down-regulating AKT signaling. Vitamin D-deficient monocytes from human cord blood have comparable Jarid2/Mef2/PGC1a expression changes and secrete miR-106b-5p, causing adipocyte insulin resistance. These findings suggest that vitamin D deficiency during development has epigenetic consequences impacting the systemic metabolic milieu.

Maternal plasma vitamin D levels across pregnancy are not associated with neonatal birthweight: findings from an Australian cohort study of low-risk pregnant women

BACKGROUND

In utero environments can be highly influential in contributing to the development of offspring obesity. Specifically, vitamin D deficiency during pregnancy is associated with adverse maternal and child health outcomes, however its relationship with offspring obesity remains unclear. We assessed maternal vitamin D status across pregnancy, change in plasma vitamin D concentrations and associations with neonatal birthweight, macrosomia and large for gestational age.

METHODS

Women (n = 221) aged 18-40 years with singleton (low-risk) pregnancies, attending antenatal clinics at a tertiary-level maternity hospital were recruited at 10-20 weeks gestation. Medical history, maternal weight and blood samples at three antenatal clinic visits were assessed; early (15 ± 3 weeks), mid (27 ± 2 weeks) and late (36 ± 1 weeks) gestation. Maternal 25(OH)D was analysed from stored plasma samples via liquid chromatography-tandem mass spectrometry (LC/MS/MS). Neonatal growth parameters were collected at birth. Unadjusted and adjusted linear and logistic regression assessed associations of maternal vitamin D with birthweight, macrosomia and large for gestational age.

RESULTS

Mean plasma 25(OH)D increased from early (83.8 ± 22.6 nmol/L) to mid (96.5 ± 28.9 nmol/L) and late (100.8 ± 30.8 nmol/L) gestation. Overall 98% of women were taking vitamin D-containing supplements throughout their pregnancy. Prevalence of vitamin D deficiency (25(OH)D < 50 nmol/L) was 6.5%, 6.3% and 6.8% at early, mid and late pregnancy respectively. No statistically significant association was found between 25(OH)D or vitamin D deficiency at any timepoint with neonatal birthweight, macrosomia or large for gestational age.

CONCLUSIONS

Prevalence of vitamin D deficiency was low in this cohort of pregnant women and likely related to the high proportion of women taking vitamin D supplements during pregnancy. Maternal 25(OH)D did not impact offspring birth weight or birth size. Future studies in high-risk pregnant populations are needed to further assess maternal vitamin D status and factors in utero which promote early life obesity.

Maternal vitamin D and growth of under-five children: a systematic review and meta-analysis of observational and interventional studies

Background

Even though previous systematic reviews have reported on the role of prenatal vitamin D on birth outcomes, its effect on child growth is poorly understood.

Objective

To synthesize a systematic summary of the literature on the effect of maternal vitamin D supplementation on the linear growth of under-five children.

Method

This study includes studies (both observational and interventional with a control group) that evaluated the effects of prenatal vitamin D status on child linear growth. The mean child length/length for age with 95% confidence interval (CI) was pooled as the weighted mean difference using a random-effects model. A funnel plot was used to assess potential publication bias.

Results

A total of 45 studies and 66 reports covering a total population of 44,992 (19,683 intervention or high vitamin D group, and 25,309 control or low vitamin D group) were analyzed. Studies spanned from 1977 to 2022. The pooled weighted mean difference was 0.4 cm (95% CI: 0.15–0.65). A subgroup analysis, based on vitamin D supplementation frequency, showed that mothers who supplemented monthly or less frequently had a 0.7 cm (95% CI: 0.2–1.16 cm) longer child. Supplementation with a dose of >2000 international units increased child length at birth. The weighted mean difference was 0.35 cm (95% CI: 0.11–0.58).

Conclusion

The evidence from this review shows that maternal supplementation of vitamin D is associated with increased birth length. This is apparent at higher doses, low frequency (monthly or less frequent), and during the second/third trimester. It appears that vitamin D supplementation during pregnancy is protective of future growth in under-five children. Clinical trials are needed to establish evidence of effectiveness for the frequency and dose of supplementation.

Effects of vitamin D on insulin resistance and fasting blood glucose in pregnant women with insufficient or deficient vitamin D: a randomized, placebo-controlled trial

BACKGROUND

Gestational diabetes is one of the most common metabolic disorders during pregnancy. Some studies have reported the effect of vitamin D deficiency on the incidence of this disorder. Therefore, the purpose of the present study was to determine the effect of vitamin D supplementation on fasting blood glucose (FBG) levels, fasting blood insulin (FBI) levels and insulin resistance index (HOMA-IR) (primary outcomes) and symptoms of depression, musculoskeletal pain, frequency of gestational diabetes and the frequency of abortion (secondary outcomes).

METHODS

In this triple-blind randomized controlled trial, 88 pregnant women at 8-10 weeks of pregnancy who had the vitamin D of less than 30 ng/ml were randomly assigned to the vitamin D group (n = 44) and control group (n = 44) using block randomization. The vitamin D group received 4,000 units of vitamin D tablets daily and the control group received placebo tablets for 18 weeks. Independent t-test, Mann-Whitney U and ANCOVA tests were used to analyze the data.

RESULTS

After the intervention, there was no statistically significant difference between the two groups in terms of FBG (P = 0.850), FBI (P = 0.353), HOMA-IR (P = 0.632), mean score of depressive symptoms (P = 0.505), frequency of gestational diabetes (P = 0.187) and frequency of abortion (P = 1.000) and there was only a difference in terms of serum vitamin D level (P = 0.016) and musculoskeletal pain including knee pain (P = 0.025), ankle pain (P < 0.001) and leg pain (P < 0.001).

CONCLUSION

Vitamin D could improve the musculoskeletal pain in pregnant women but couldn't decrease FBG, FBI, HOMA-IR, depression symptoms score, incidence of GDM and abortion.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials (IRCT): IRCT20120718010324N59. Date of registration: 4/11/2020. URL: https://en.irct.ir/user/trial/50973/view ; Date of first registration: 21/11/2020.

The Gestational Effects of Maternal Bone Marker Molecules on Fetal Growth, Metabolism and Long-Term Metabolic Health: A Systematic Review

Fetal exposure in adverse environmental factors during intrauterine life can lead to various biological adjustments, affecting not only in utero development of the conceptus, but also its later metabolic and endocrine wellbeing. During human gestation, maternal bone turnover increases, as reflected by molecules involved in bone metabolism, such as vitamin D, osteocalcin, sclerostin, sRANKL, and osteoprotegerin; however, recent studies support their emerging role in endocrine functions and glucose homeostasis regulation. Herein, we sought to systematically review current knowledge on the effects of aforementioned maternal bone biomarkers during pregnancy on fetal intrauterine growth and metabolism, neonatal anthropometric measures at birth, as well as on future endocrine and metabolic wellbeing of the offspring. A growing body of literature converges on the view that maternal bone turnover is likely implicated in fetal growth, and at least to some extent, in neonatal and childhood body composition and metabolic wellbeing. Maternal sclerostin and sRANKL are positively linked with fetal abdominal circumference and subcutaneous fat deposition, contributing to greater birthweights. Vitamin D deficiency correlates with lower birthweights, while research is still needed on intrauterine fetal metabolism, as well as on vitamin D dosing supplementation during pregnancy, to diminish the risks of low birthweight or SGA neonates in high-risk populations.

The influence of maternal levels of vitamin D and adiponectin on offspring's health

BACKGROUND

From the very beginning of life, biological events in the intrauterine environment influence the developing child, its growth, maturation and adaptation. The aim of this study was to assess the impact of maternal vitamin D and adiponectin status on offspring growth, general and bone health.

METHODS

162 healthy pregnant women were included in the study, with their vitaminD and adiponectin levels measured in the 32 nd week of pregnancy. Body weight and bone mineral density measurements of their offspring were performed at birth and at the age of three, six, nine and twelve months. Information on children's infectious, allergic and chronic disease was collected from their medical records.

RESULTS

Vitamin D insufficiency/deficiency was present in 44% of pregnant women. There was no significant association between maternal vitamin D during pregnancy and offspring body weight at birth or later, as well as between maternal vitamin D and newborn bone mineral density. Additionally, there was no significant association between maternal vitamin D and infectious, allergic or other chronic diseases in offspring. A negative correlation between maternal adiponectin and offspring's body weight at birth was observed (r = - 0.37, p = 0.002), while association with bone mineral density in newborns was not significant.

CONCLUSION

Despite the significant prevalence of vitamin D insufficiency among pregnant women, it did not influence growth or health of their offspring in this study. Maternal adiponectin levels showed an inverse relationship with birth weight of the infants, which may highlight the important link between maternal health and the offspring's growth.

Calcifediol (25OHD) Deficiency and Its Treatment in Women's Health and Fertility

Currently, there is abundant scientific evidence showing that the vitamin D endocrine system (VDES) is a highly complex endocrine system with multiple actions in different regions of the body. The unequivocal presence of vitamin D receptors in different tissues related to fertility, and to specific aspects of women's health such as pregnancy, undoubtedly implies functions of this steroid hormone in both male and female fertility and establishes relationships with different outcomes of human gestation. In order to review the role of the VDES in human fertility, we evaluated the relationships established between 25-hydroxyvitamin D (calcifediol) deficiency and in vitro fertilization, as well as aspects related to ovarian reserve and fertility, and commonly diagnosed endocrinopathies such as polycystic ovary disease. Likewise, we briefly reviewed the relationships between calcifediol deficiency and uterine fibroids, as well as the role that treatment may have in improving human fertility. Finally, the best scientific evidence available on the consequences of calcifediol deficiency during pregnancy is reviewed in relation to those aspects that have accumulated the most scientific literature to date, such as the relationship with the weight of the newborn at the time of delivery, the appearance of preeclampsia, and the risk of developing gestational diabetes and its final consequences for the pregnancy. To date, there is no definitive consensus on the necessary dose for treatment of calcifediol deficiency in the therapeutic management of infertility or during pregnancy. Large prospective clinical intervention studies are needed to clarify the benefits associated with this supplementation and the optimal dose to use in each situation. Although most intervention studies to date have been conducted with cholecalciferol, due to its much longer history of use in daily care, the use of calcifediol to alleviate 25-hydroxyvitamin D deficiency seems safe, even during pregnancy. The unequivocal presence of vitamin D receptors in very different tissues related to human fertility, both male and female, as well as in structures typical of pregnancy, allows us to investigate the crucial role that this steroid hormone has in specific aspects of women's health, such as pregnancy and the ability to conceive. Well-designed clinical studies are needed to elucidate the necessary dose and the best form of treatment to resolve the very common calcifediol deficiency in women of reproductive age.

Effect of maternal vitamin D status on risk of adverse birth outcomes: a systematic review and dose-response meta-analysis of observational studies

PURPOSE

Accumulating evidence suggests that vitamin D deficiency increases the risk of adverse perinatal outcomes. However, the dose-response relationship between maternal vitamin D status and adverse birth outcomes remains unclear. Focusing on prospective observational studies, we aimed to explore the dose-response relationship of vitamin D status with the risk of low birth weight (LBW), macrosomia (MA), preterm birth (PTB), small for gestational age (SGA), and intrauterine growth restriction (IUGR).

METHODS

Databases including PubMed, Embase, Scopus, and Web of Science were used up to 19 January 2021 to search for observational studies that fulfilled criteria as follows: cohort studies, case-cohort studies, or nested case-control studies. Random-effects models were used to pool relative risks (RRs) and 95% confidence intervals (CIs) in the observational studies.

RESULTS

A total of 72 publications were included in this systematic review and 71 in the meta-analysis. Maternal 25-hydroxyvitamin D (25(OH)D) concentrations were inversely associated with the risk of LBW (RR: 0.65; 95% CI 0.48-0.86), PTB (RR: 0.67; 95% CI 0.57-0.79), and SGA (RR: 0.61; 95% CI 0.49-0.76) in the highest versus lowest meta-analysis, but not associated with MA and IUGR. Linear dose-response analysis showed that each 25 nmol/L increase in 25(OH)D was associated with a 6% and 10% reduction in the risk of PTB (RR: 0.94; 95% CI 0.90-0.98) and SGA (RR: 0.90; 95% CI 0.84-0.97), respectively.

CONCLUSION

Our study suggests that a sufficient vitamin D status during pregnancy is protective against the risk of LBW, PTB, and SGA.

Impact of Maternal and Neonatal Vitamin D Status on the Development of Congenital Anomalies in Egyptian Model

Background: Vitamin D (VD) is a remarkable problem during pregnancy. VD plays a crucial role in cellular growth and differentiation during embryogenesis. VD deficiency in pregnancy is associated with various maternal and neonatal comorbidities.  Aim: In this study, we aimed to evaluate the potential association between maternal and neonatal vitamin D status and the subsequent development of congenital anomalies. Patients and methods: A case-control study involving 30 mothers and their neonates born with gross structural congenital anomalies as cases and 30 mothers and their healthy neonates as controls recruited from Ain Shams University Children Hospital. Maternal and Neonatal blood samples were obtained to determine serum 25-hydroxyvitamin D.  The 25-hydroxyvitamin D concentration was stratified into a severe deficient<10ng/ml, deficient <20ng/ml, insufficient 20-29ng/ml and sufficient >30ng/ml. Status above 150ng/ml presents high risk of toxicity.  Results: There were statistically significant differences between the two groups regarding maternal and neonatal vitamin D serum level within 29 days postpartum. Mean maternal vitamin D level in cases was 23.8ng/ml versus 42.13ng/ml in controls (P = 0,000). Mean neonatal vitamin D level in cases was 15.97ng/ml versus 28.9ng/ml in controls (P = 0,000).There was significant positive correlation between both maternal and neonatal vitamin D level with birth weight. Conclusion: A compromised maternal vitamin D status is associated with an increased prevalence of congenital anomalies in offspring. Therefore, improvement of the periconceptional maternal vitamin D status is recommended.

Vitamin D Status during Pregnancy versus the Anthropometric Parameters of Two- and Four-Year-Olds: A Pilot Study

Apart from being associated with a well-documented risk for adverse pregnancy outcomes, maternal deficiency of vitamin D may also negatively affect the physical development of their children. The aim of the study was to evaluate the relationship between maternal as well as umbilical cord blood levels of vitamin D and the weight and height values of two- and four-year-olds. The study was conducted in a group of 52 'mother-child' pairs. On the day of the delivery, total 25(OH)D concentration in blood was measured using immunological tests (LIAISON). Weight and height values were obtained from the database of routine health checks for children aged two and four, which are obligatory in Poland. Multiple regression analysis was used for statistical analysis. No association was detected between maternal-neonatal concentrations of vitamin D and weight and height values of the investigated two- and four-year-olds despite extreme differences in maternal (4.0-37.7 ng/mL) and neonatal (5.9-46.6 ng/mL) concentrations and the fact that vitamin D deficiency was detected in almost 54% of the mothers and 37% of the newborns. Therefore, no relationship between maternal-fetal vitamin D concentrations and the anthropometric parameters of the investigated children up to the age of four was found.

Maternal Diet, Infection, and Risk of Cord Blood Inflammation in the Bangladesh Projahnmo Pregnancy Cohort

Inflammation may adversely affect early human brain development. We aimed to assess the role of maternal nutrition and infections on cord blood inflammation. In a pregnancy cohort in Sylhet, Bangladesh, we enrolled 251 consecutive pregnancies resulting in a term livebirth from July 2016-March 2017. Stillbirths, preterm births, and cases of neonatal encephalopathy were excluded. We prospectively collected data on maternal diet (food frequency questionnaire) and morbidity, and analyzed umbilical cord blood for interleukin (IL)-1α, IL-1β, IL-6, IL-8 and C-reactive protein. We determined associations between nutrition and infection exposures and cord cytokine elevation (≥75% vs. <75%) using logistic regression, adjusting for confounders. One-third of mothers were underweight (BMI < 18.5 kg/m2) at enrollment. Antenatal and intrapartum infections were observed among 4.8% and 15.9% of the sample, respectively. Low pregnancy intakes of B vitamins (B1, B2, B3, B6, B9 (folate)), fat-soluble vitamins (D, E), iron, zinc, and linoleic acid (lowest vs. middle tertile) were associated with higher risk of inflammation, particularly IL-8. There was a non-significant trend of increased risk of IL-8 and IL-6 elevation with history of ante-and intrapartum infections, respectively. In Bangladesh, improving micronutrient intake and preventing pregnancy infections are targets to reduce fetal systemic inflammation and associated adverse neurodevelopmental outcomes.

Early-Life Effects of Vitamin D: A Focus on Pregnancy and Lactation

Vitamin D is an endocrine regulator of calcium and bone metabolism. Yet, its effects include other systems, such as innate and adaptive immunity. Unique to pregnancy, circulating 1,25-dihydroxyvitamin D (1,25[OH]2D) increases early on to concentrations that are 2-3 times prepregnant values. At no other time during the lifecycle is the conversion of 25-hydroxyvitamin D (25[OH]D) to 1,25(OH)2D directly related and optimized at ≥100 nmol/L. Vitamin D deficiency appears to affect pregnancy outcomes, yet randomized controlled trials of vitamin D supplementation achieve mixed results depending on when supplementation is initiated during pregnancy, the dose and dosing interval, and the degree of deficiency at the onset of pregnancy. Analysis of trials on an intention-to-treat basis as opposed to the use of 25(OH)D as the intermediary biomarker of vitamin D metabolism yields differing results, with treatment effects often noted only in the most deficient women. Immediately after delivery, maternal circulating 1,25(OH)2D concentrations return to prepregnancy baseline, at a time when a breastfeeding woman has increased demands of calcium, beyond what was needed during the last trimester of pregnancy, making one question why 1,25(OH)2D increases so significantly during pregnancy. Is it to serve as an immune modulator? The vitamin D content of mother's milk is directly related to maternal vitamin D status, and if a woman was deficient during pregnancy, her milk will be deficient unless she is taking higher doses of vitamin D. Because of this relative "deficiency," there is a recommendation that all breastfed infants receive 400 IU vitamin D3/day starting a few days after birth. The alternative - maternal supplementation with 6,400 IU vitamin D3/day, effective in safely raising maternal circulating vitamin D, that of her breast milk, and effective in achieving sufficiency in her recipient breastfeeding infant - remains a viable option. Additional research is needed to understand vitamin D's influence on pregnancy health and the effect of maternal supplementation on breast milk's immune signaling.

Serum 25 Hydroxyvitamin D Levels During Pregnancy in Women with Asthma: Associations with Maternal Characteristics and Adverse Maternal and Neonatal Outcomes

Low 25-hydroxyvitamin D (25(OH)D) levels are common in pregnancy and associated with adverse maternal/neonatal outcomes. In pregnant women with asthma, this study examined the association of lifestyle- and asthma-related factors on 25(OH)D levels and maternal/neonatal outcomes by vitamin D status. Serum 25(OH)D was measured at 16 and 35 weeks gestation in women with asthma (n = 103). Body mass index (BMI), gestational weight gain (GWG), smoking status, inhaled corticosteroid (ICS) use, asthma control, airway inflammation, and exacerbations, and maternal/neonatal outcomes were collected. Baseline and change (Δ) in 25(OH)D were modelled separately using backward stepwise regression, adjusted for season and ethnicity. Maternal/neonatal outcomes were compared between low (25(OH)D < 75 nmol/L at both time points) and high (≥75 nmol/L at one or both time points) vitamin D status. Fifty-six percent of women had low vitamin D status. Obesity was significantly associated with lower baseline 25(OH)D (Adj-R² = 0.126, p = 0.008); ICS and airway inflammation were not. Excess GWG and season of baseline sample collection were significantly associated with Δ25(OH)D (Adj-R² = 0.405, p < 0.0001); asthma-related variables were excluded (p > 0.2). Preeclampsia was more common in the low (8.6%) vs. high (0%) vitamin D group (p < 0.05). Obesity and excess GWG may be associated with gestational 25(OH)D levels, highlighting the importance of antenatal weight management.

Association between vitamin D level and bronchopulmonary dysplasia: A systematic review and meta-analysis

Neonatal vitamin D deficiency is common and is associated with development of pulmonary disease in children and adults. While the role of vitamin D in normal lung development is well established, the association between vitamin D deficiency and bronchopulmonary dysplasia (BPD) remains unclear. The present meta-analysis was conducted to evaluate the relationship between vitamin D and BPD. We identified relevant studies (n = 8) using the PubMed, EMBASE, Cochrane Library, and KoreaMed databases and applied the Newcastle–Ottawa Scale to assess the methodological components of each study, and used I² statistic to evaluate heterogeneity. Comprehensive Meta-Analysis software version 3.3 was used for the statistical analysis. A total of 909 infants were included, of whom 251 (27.6%) were diagnosed with BPD. We found that both vitamin D deficiency at birth (four studies; OR 2.405; 95% CI 1.269 to 4.560; p = 0.007) and low levels of vitamin D at birth (four studies; standardized mean difference -1.463; 95% CI -2.900 to -0.027; p = 0.046) were associated with BPD. The compiled data suggest that antenatal vitamin D deficiency and low vitamin D levels are associated with neonatal BPD.