Vitamin D during pregnancy and maternal, neonatal and infant health outcomes: a systematic review and meta-analysis

High Prevalence of Vitamin D Deficiency in Native versus Migrant Mothers and Newborns in the North of Italy: A Call to Act with a Stronger Prevention Program

Background

Vitamin D status during pregnancy is related to neonatal vitamin D status. Vitamin D deficiency has been associated with an increased risk of rickets in children and osteomalacia in adults. Aim of this study was to investigate 25OHD levels in maternal serum and in neonatal blood spots in native and migrant populations living in Novara (North Italy, 45°N latitude).

Methods and Findings

We carried out a cross sectional study from April 1st 2012 to March 30th 2013, in a tertiary Care Center. Maternal blood samples after delivery and newborns' blood spots were analyzed for 25OHD levels in 533 pairs. Maternal country of origin, skin phototype, vitamin D dietary intake and supplementation during pregnancy were recorded. Multivariate regression analysis, showed a link between neonatal and maternal 25OHD levels (R-square:0.664). Severely deficient 25OHD values (<25 nmol/L) were found in 38% of Italian and in 76.2% of migrant’s newborns (p <0.0001), and in 18% of Italian and 48,4% of migrant mothers (p <0.0001) while 25OHD deficiency (≥25 and <50 nmol/L) was shown in 40.1% of Italian and 21.7% of migrant’s newborns (p <0.0001), and in 43.6% of Italian and 41.3% of migrant mothers (p <0.0001). Italian newborns and mothers had higher 25OHD levels (34.4±19.2 and 44.9±21.2nmol/L) than migrants (17.7±13.7 and 29.7±16.5nmol/L; p<0.0001). A linear decrease of 25OHD levels was found with increasing skin pigmentation (phototype I 42.1 ±18.2 vs phototype VI 17.9±10.1 nmol/l; p<0.0001). Vitamin D supplementation resulted in higher 25OHD values both in mothers and in their newborns (p<0.0001).

Conclusions

Vitamin D insufficiency in pregnancy and in newborns is frequent especially among migrants. A prevention program in Piedmont should urgently be considered and people identified as being at risk should be closely monitored. Vitamin D supplementation should be taken into account when considering a preventative health care policy.

Recommendations of the Brazilian Society of Endocrinology and Metabology (SBEM) for the diagnosis and treatment of hypovitaminosis D

OBJECTIVE

The objective is to present an update on the diagnosis and treatment of hypovitaminosis D, based on the most recent scientific evidence.

MATERIALS AND METHODS

The Department of Bone and Mineral Metabolism of the Brazilian Society of Endocrinology and Metabology (SBEM) was invited to generate a document following the rules of the Brazilian Medical Association (AMB) Guidelines Program. Data search was performed using PubMed, Lilacs and SciELO and the evidence was classified in recommendation levels, according to the scientific strength and study type.

CONCLUSION

A scientific update regarding hypovitaminosis D was presented to serve as the basis for the diagnosis and treatment of this condition in Brazil.

High prevalence of vitamin D deficiency in pregnant Korean women: the first trimester and the winter season as risk factors for vitamin D deficiency

We investigated the vitamin D status of Korean women during pregnancy and assessed the effects of vitamin D deficiency on two pregnancy outcomes; preterm births and the births of small for gestational age. We measured the serum 25-hydroxyvitamin D levels in 220 pregnant Korean women who were recruited prospectively and compared these levels with those of 500 healthy non-pregnant women. We analyzed vitamin D status according to patient demographics, season, and obstetrical characteristics; moreover, we also assessed pregnancy outcomes. The overall prevalence of vitamin D deficiency(<20 ng/mL) in pregnant women and healthy non-pregnant women was 77.3% and 79.2%; respectively; and the prevalence of severe vitamin D deficiency (<10 ng/mL) was 28.6% and 7.2%; respectively (p < 0.05). Vitamin D deficiency was more prevalent in the winter (100%) than in the summer (45.5%) in pregnant Korean women. A higher risk of vitamin D deficiency was observed in the first trimester than in the third trimester (adjusted OR 4.3; p < 0.05). No significant association was observed between vitamin D deficiency and any of the pregnancy outcomes examined. Further research focusing on the long-term consequences of vitamin D deficiency during pregnancy in Korean women is warranted.

Higher vitamin D intake during pregnancy is associated with reduced risk of dental caries in young Japanese children

PURPOSE

The intrauterine environment, including maternal nutrition status, may affect the development, formation, and mineralization of children's teeth. We assessed the relationship between self-reported maternal dietary vitamin D intake during pregnancy and the risk of dental caries among young Japanese children.

METHODS

This study is based on a prospective analysis of 1210 Japanese mother-child pairs. Information on maternal intake during pregnancy was collected using a validated diet history questionnaire. Data on oral examination at 36-46 months of age were obtained from the mothers, who transcribed the information from their maternal and child health handbooks to our self-administered questionnaire. Children were classified as having dental caries if one or more primary teeth had decayed or had been filled.

RESULTS

Compared with the lowest quartile of maternal vitamin D intake during pregnancy, adjusted odds ratios (95% confidence intervals) for quartiles 2, 3, and 4 were 1.06 (0.72-1.56), 0.53 (0.34-0.81), and 0.67 (0.44-1.02), respectively (P for trend = .01). When maternal vitamin D intake was treated as a continuous variable, the adjusted odds ratio (95% confidence interval) was 0.94 (0.89-0.995).

CONCLUSIONS

Higher maternal vitamin D intake during pregnancy may be associated with a lower risk of dental caries in children.

Vitamin D status in early pregnancy and risk of preeclampsia

OBJECTIVE

We sought to examine the association between maternal serum 25-hydroxyvitamin D (25[OH]D) concentration in early pregnancy and the subsequent diagnosis of preeclampsia (PE).

STUDY DESIGN

This was a nested case-control study from 2 prospective Canadian cohorts conducted in Quebec City, Quebec, and Halifax, Nova Scotia, from 2002 through 2010. Participants were pregnant women (n = 169 cases with PE and 1975 controls). Maternal serum was drawn <20 weeks of gestation, and 25(OH)D measurement was performed. Cases were ascertained from medical records. Logistic regression analysis was used to estimate adjusted odds ratios with 95% confidence intervals.

RESULTS

Women who developed PE had a significantly lower 25(OH)D concentration at a mean gestational age of 14 weeks compared with women in the control group (mean ± SD 25[OH]D 47.2 ± 17.7 vs 52.3 ± 17.2 nmol/L, P < .0001). Women with 25(OH)D <30 nmol/L compared to those with at least 50 nmol/L had a greater risk of developing PE (adjusted odds ratio, 2.23; 95% confidence interval, 1.29-3.83) after adjustment for prepregnancy body mass index, maternal age, smoking, parity, season and year of blood collection, gestational week at blood collection, and cohort site. Exploratory analysis with cubic splines demonstrated a dose-response relationship between maternal 25(OH)D and risk of PE, up to levels around 50 nmol/L, where the association appeared to plateau.

CONCLUSION

Maternal vitamin D deficiency early in pregnancy defined as 25(OH)D <30 nmol/L may be an independent risk factor for PE. The relevance of vitamin D supplementation for women of childbearing age should be explored as a strategy for reducing PE and for promoting a healthier pregnancy.

Calcium plus vitamin D supplementation affects pregnancy outcomes in gestational diabetes: randomized, double-blind, placebo-controlled trial

OBJECTIVE

The present study was designed to assess the effects of Ca+vitamin D supplementation on pregnancy outcomes in women with gestational diabetes mellitus (GDM).

DESIGN

A randomized, double-blind, placebo-controlled trial was conducted among sixty women with GDM. Participants were divided into two groups to receive Ca+vitamin D supplements or placebo. Individuals in the Ca+vitamin D group (n 30) received 1000 mg Ca/d and two pearls containing 1250 µg (50 000 IU) of cholecalciferol (vitamin D(3)) during the intervention (one at study baseline and another at day 21 of the intervention); those in the placebo group (n 30) received two placebos of vitamin D at the mentioned times and placebos of Ca every day for 6 weeks. Pregnancy outcomes were determined.

SETTING

A urban community setting in Arak, Iran.

SUBJECTS

Sixty women with GDM and their newborns, living in Arak, Iran were enrolled.

RESULTS

Women treated with Ca+vitamin D had a significant decrease in caesarean section rate (23·3 % v. 63·3 %, P=0·002) and maternal hospitalization (0 v. 13·3 %, P=0·03) compared with those receiving placebo. In addition, newborns of GDM women randomized to Ca+vitamin D had no case of macrosomia, while the prevalence of macrosomia among those randomized to placebo was 13·3 % (P=0·03). Lower rates of hyperbilirubinaemia (20·0 % v. 56·7 %, P=0·03) and hospitalization (20·0 % v. 56·7 %, P=0·03) were also seen in the supplemented group of newborns than in the placebo group.

CONCLUSIONS

Ca+vitamin D supplementation for 6 weeks among pregnant women with GDM led to decreased caesarean section rate and maternal hospitalization, and decreased macrosomia, hyperbilirubinaemia and hospitalization in newborns.

Placental vitamin D receptor expression is decreased in human idiopathic fetal growth restriction

Fetal growth restriction (FGR) affects up to 5 % of pregnancies worldwide, and trophoblast function plays a significant role on the outcome. An epidemiological study has linked vitamin D deficiency to adverse perinatal outcomes, which include decreased birth weight. The placenta as an important source of vitamin D regulates its metabolism through the vitamin D receptor (VDR), but the mechanism by which VDR regulates trophoblast function is poorly understood. Our study aimed at determining placental VDR expression in FGR and gestation-matched control (GMC) pregnancies and identifying the actions of VDR in trophoblast differentiation and apoptosis. Placentae were collected from a well-defined cohort of idiopathic FGR and GMC pregnancies. VDR mRNA and protein expressions were determined by PCR, immunohistochemistry and immunoblotting, while functional consequences of VDR inactivation in vitro were determined on BeWo cells by determining changes in differentiation, attachment and apoptosis. Significant decreases in VDR mRNA expression (p = 0.0005) and protein expression (p = 0.0003) were observed in the FGR samples, while VDR inactivation, which showed markers for differentiation, cell attachment and apoptosis, was significantly increased. Thus, decreased placental VDR may contribute to uncontrolled premature differentiation and apoptosis of trophoblasts that are characteristics of idiopathic FGR pregnancies.

KEY MESSAGE

Fetal growth restriction (FGR) affects up to 5 % of all pregnancies worldwide. FGR is the second highest cause of perinatal mortality and morbidity. The placenta plays a pivotal role in vitamin D metabolism during pregnancy. Vitamin D deficiency is associated with adverse pregnancy outcomes. Placental vitamin D receptor expression is decreased in FGR.

[Vitamin D deficiency in pregnancy and its impact on the fetus, the newborn and in childhood]

OBJECTIVE

Vitamin D deficiency (VDD) in pregnant women and their children is an important health problem with severe consequences for the health of both. Thus, the objectives of this review were to reassess the magnitude and consequences of VDD during pregnancy, lactation and infancy, associated risk factors, prevention methods, and to explore epigenetic mechanisms in early fetal life capable of explaining many of the non-skeletal benefits of vitamin D (ViD).

DATA SOURCE

Original and review articles, and consensus documents with elevated level of evidence for VDD-related clinical decisions on the health of pregnant women and their children, as well as articles on the influence of ViD on epigenetic mechanisms of fetal programming of chronic diseases in adulthood were selected among articles published on PubMed over the last 20 years, using the search term VitD status, in combination with Pregnancy, Offspring health, Child outcomes, and Programming.

DATA SYNTHESIS

The following items were analyzed: ViD physiology and metabolism, risk factors for VDD and implications in pregnancy, lactation and infancy, concentration cutoff to define VDD, the variability of methods for VDD detection, recommendations on ViD replacement in pregnant women, the newborn and the child, and the epigenetic influence of ViD.

CONCLUSIONS

VDD is a common condition among high-risk pregnant women and their children. The routine monitoring of serum 25(OH)D3 levels in antenatal period is mandatory. Early preventive measures should be taken at the slightest suspicion of VDD in pregnant women, to reduce morbidity during pregnancy and lactation, as well as its subsequent impact on the fetus, the newborn and the child.

Management of multiple sclerosis during pregnancy and the reproductive years: a systematic review

OBJECTIVE

To examine the evidence guiding management of multiple sclerosis (MS) in reproductive-aged women.

DATA SOURCES

We conducted an electronic literature search using PubMed, ClinicalTrials.gov, and other available resources. The following keywords were used: "multiple sclerosis" and "pregnancy." We manually searched the reference lists of identified studies.

METHODS OF STUDY SELECTION

Two reviewers categorized all studies identified in the search by management topic, including effect of pregnancy on MS course, fetal risks associated with disease-modifying treatments during pregnancy, and management of patients off disease-modifying treatment. We categorized studies by strength of evidence and included prior meta-analyses and systematic studies. These studies were then summarized and discussed by an expert multidisciplinary team.

TABULATION, INTEGRATION, AND RESULTS

The risk of MS relapses is decreased during pregnancy and increased postpartum. Data are lacking regarding the risks of disease-modifying treatments during pregnancy. There may be an increased risk of MS relapses after use of assisted reproductive techniques. There does not appear to be a major increase in adverse outcomes in newborns of mothers with MS.

CONCLUSION

Although there are many unmet research needs, the reviewed data support the conclusion that in the majority of cases, women with MS can safely choose to become pregnant, give birth, and breastfeed children. Clinical management should be individualized to optimize both the mother's reproductive outcomes and MS course.

Regulation of calcitriol biosynthesis and activity: focus on gestational vitamin D deficiency and adverse pregnancy outcomes

Vitamin D has garnered a great deal of attention in recent years due to a global prevalence of vitamin D deficiency associated with an increased risk of a variety of human diseases. Specifically, hypovitaminosis D in pregnant women is highly common and has important implications for the mother and lifelong health of the child, since it has been linked to maternal and child infections, small-for-gestational age, preterm delivery, preeclampsia, gestational diabetes, as well as imprinting on the infant for life chronic diseases. Therefore, factors that regulate vitamin D metabolism are of main importance, especially during pregnancy. The hormonal form and most active metabolite of vitamin D is calcitriol. This hormone mediates its biological effects through a specific nuclear receptor, which is found in many tissues including the placenta. Calcitriol synthesis and degradation depend on the expression and activity of CYP27B1 and CYP24A1 cytochromes, respectively, for which regulation is tissue specific. Among the factors that modify these cytochromes expression and/or activity are calcitriol itself, parathyroid hormone, fibroblast growth factor 23, cytokines, calcium and phosphate. This review provides a current overview on the regulation of vitamin D metabolism, focusing on vitamin D deficiency during gestation and its impact on pregnancy outcomes.

Vitamin D promotes human extravillous trophoblast invasion in vitro

INTRODUCTION

Incomplete human extravillous trophoblast (EVT) invasion of the decidua and maternal spiral arteries is characteristic of pre-eclampsia, a condition linked to low maternal vitamin D status. It is hypothesized that dysregulated vitamin D action in uteroplacental tissues disrupts EVT invasion leading to malplacentation.

METHODS

This study assessed the effects of the active vitamin D metabolite, 1,25-dihydroxyvitamin D3 (1,25-D3), and its precursor, 25-hydroxyvitamin D3 (25-D3), on primary human EVT isolated from first trimester pregnancies. Expression of EVT markers (cytokeratin-7, HLA-G), the vitamin D-activating enzyme (CYP27B1) and 1,25-D3 receptor (VDR) was assessed by immunocytochemistry. EVT responses following in vitro treatment with 1,25-D3 (0-10 nM) or 25-D3 (0-100 nM) for 48-60 h were assessed using quantitative RT-PCR (qRT-PCR) analysis of key target genes. Effects on EVT invasion through Matrigel(®) were quantified alongside zymographic analysis of secreted matrix metalloproteinases (MMPs). Effects on cell viability were assessed by measurement of MTT.

RESULTS

EVT co-expressed mRNA and protein for CYP27B1 and VDR, and demonstrated induction of mRNA encoding vitamin D-responsive genes, 24-hydroxylase (CYP24A1) and cathelicidin following 1,25-D3 treatment. EVT could respond to 1,25-D3 and 25-D3, both of which significantly increased EVT invasion, with maximal effect at 1 nM 1,25-D3 (1.9-fold; p < 0.01) and 100 nM 25-D3 (2.2-fold; p < 0.05) respectively compared with untreated controls. This was accompanied by increased pro-MMP2 and pro-MMP9 secretion. The invasion was independent of cell viability, which remained unchanged.

DISCUSSION

These data support a role for vitamin D in EVT invasion during human placentation and suggest that vitamin D-deficiency may contribute to impaired EVT invasion and pre-eclampsia.

Does prenatal exposure to vitamin D-fortified margarine and milk alter birth weight? A societal experiment

The present study examined whether exposure to vitamin D from fortified margarine and milk during prenatal life influenced mean birth weight and the risk of high or low birth weight. The study was based on the Danish vitamin D fortification programme, which was a societal intervention with mandatory fortification of margarine during 1961-1985 and voluntary fortification of low-fat milk between 1972 and 1976. The influence of prenatal vitamin D exposure on birth weight was investigated among 51 883 Danish children, by comparing birth weight among individuals born during 2 years before or after the initiation and termination of vitamin D fortification programmes. In total, four sets of analyses were performed. Information on birth weight was available in the Copenhagen School Health Record Register for all school children in Copenhagen. The mean birth weight was lower among the exposed than non-exposed children during all study periods (milk initiation - 20·3 (95 % CI - 39·2, - 1·4) g; milk termination - 25·9 (95 % CI - 46·0, - 5·7) g; margarine termination - 45·7 (95 % CI - 66·6, - 24·8) g), except during the period around the initiation of margarine fortification, where exposed children were heavier than non-exposed children (margarine initiation 27·4 (95 % CI 10·8, 44·0) g). No differences in the odds of high (>4000 g) or low ( < 2500 g) birth weight were observed between the children exposed and non-exposed to vitamin D fortification prenatally. Prenatal exposure to vitamin D from fortified margarine and milk altered birth weight, but the effect was small and inconsistent, reaching the conclusion that vitamin D fortification seems to be clinically irrelevant in relation to fetal growth.

High prevalence of vitamin D deficiency among pregnant women in a Turkish population and impact on perinatal outcomes

OBJECTIVE

Maternal vitamin D deficiency is a major public health problem. The aim of this study is to investigate the influence of vitamin D deficiency on perinatal results in primigravida.

METHODS

One-hundred fifty-two healthy nullipar women were included in the study. Pregnant women with serum vitamin D levels <15ng/ml were defined as Group I and ≥15 ng/dl were defined as Group II; data were evaluated retrospectively. Type of delivery, gestational age at birth, birth weight, intensive care of the newborn, peri-and postpartum complications were recorded. Statistical analyses were performed with SPSS for Windows (version 16.0 ). Categorical variables were assessed using chi-squared test. The numeric variables were analyzed using Student's t-test and one-way ANOVA.

RESULTS

44.6% of pregnant women were found to have vitamin D deficiency. The mean serum vitamin D levels for Groups I and II were 10.8 ± 3.8 and 23.8 ± 13.3 ng/ml, respectively. SGA deliveries were detected in 16.66% and 4.87% of the primigravidas with and without vitamin D deficiency, respectively.

CONCLUSIONS

This study has shown that maternal vitamin D deficiency is related with an increased risk of SGA delivery. Further studies are needed to explain the relationship with vitamin D deficiency and poor perinatal outcomes.

Preeclampsia and maternal cardiovascular disease: consequence or predisposition?

Formerly preeclamptic women stand a higher chance of developing cardiovascular disease (CVD) later in life and may experience a shortened life span. This review updates the pathophysiology and definition of this complex disease and highlights the protective role of pregnancy by considering the relationship between pregnancy interval and likelihood of disease recurrence. The evidence for persistent maternal cardiovascular impairment following preeclampsia (PE) is considered, e.g. postpartum changes in CVD occurrence, blood pressure elevation and changes in the renin-angiotensin-aldosterone system). Since maternal endothelial dysfunction is a hallmark of PE, we summarize the evidence for reduced flow-mediated dilation in women with previous PE, and consider the utility and shortcomings of this clinical measure. In addition to viewing postpartum changes as a consequence of this disease, we consider the alternative view that PE might be the manifestation of a maternal phenotype that already has some predisposition to or is in the earlier stages of CVD; in this case, some of the postpartum residual deficits (or their antecedents) may have already been present prior to pregnancy. Finally, we consider the use of novel biomarkers for predicting or detecting PE prior to the appearance of clinical symptoms.

Maternal vitamin D status and infant anthropometry in a US multi-centre cohort study

BACKGROUND

Maternal vitamin D status in pregnancy is linked to foetal growth and may impact infant growth.

AIM

This study examined the association between maternal vitamin D status and infant anthropometry.

SUBJECTS AND METHODS

Data came from n = 2473 mother-child pairs from the 12-site US Collaborative Perinatal Project (1959-1965). Maternal serum 25-hydroxyvitamin D (25(OH)D) was measured at ≤ 26 weeks gestation. Multivariate-adjusted linear mixed models were used to relate maternal vitamin D status to infant z-scores for length (LAZ), head circumference (HCZ), weight (WAZ) and BMI (BMIZ), measured at birth and 4, 8 and 12 months.

RESULTS

Infants with maternal 25(OH)D ≥30 nmol/L vs <30 nmol/L had LAZ and HCZ measures 0.13 (95% CI = 0.03-0.23) and 0.20 (95% CI = 0.11-0.28) units higher, respectively, across the first year of life. Similar differences in WAZ and BMIZ at birth were resolved by 12 months of age due to interactions indicating steeper age slopes in infants with maternal 25(OH)D <30 nmol/L.

CONCLUSION

Low maternal vitamin D status was associated with deficits at birth in infant weight and BMI that were recouped across the first year of life; associations with reduced measures of linear and skeletal growth were sustained from birth to 12 months.

Prenatal vitamin D₃ supplementation suppresses LL-37 peptide expression in ex vivo activated neonatal macrophages but not their killing capacity

Vitamin D has regulatory effects on innate immunity. In the present study, we aimed to assess the effect of prenatal vitamin D₃ (vitD₃) supplementation on neonatal innate immunity in a randomised, placebo-controlled trial by evaluating cathelicidin (LL-37) expression and the killing capacity of macrophages. Healthy pregnant women (n 129) attending a clinic in Dhaka were randomised to receive either a weekly oral dose of 0·875 mg vitD₃ or placebo starting from 26 weeks of gestation up to delivery. Serum, plasma and monocyte-derived macrophages (MDM) were obtained from the cord blood. 25-Hydroxyvitamin D (25(OH)D) concentration was measured in serum. MDM were stimulated with or without Toll-like-receptor 4 ligand (TLR4L). Innate immune function was assessed by measuring LL-37 peptide levels in the culture supernatant of MDM by ELISA, LL-37 transcript levels by quantitative PCR, and ex vivo bactericidal capacity of MDM. VitD₃ supplementation did not increase LL-37 peptide levels in plasma or in the extracellular fluid of macrophages with or without TLR4L induction. However, stimulated intracellular LL-37 expression (ratio of stimulated:unstimulated MDM) was significantly reduced in the vitamin D group v. placebo (P=0·02). Multivariate-adjusted analyses showed that intracellular LL-37 peptide concentration from stimulated MDM was inversely associated with 25(OH)D concentration in serum (P=0·03). TLR4L stimulation increased the bactericidal capacity of MDM compared with the unstimulated ones (P=0·01); however, there was no difference in killing capacity between the two groups. A weekly dose of 0·875 mg vitD₃ to healthy pregnant women suppressed the intracellular LL-37 peptide stores of activated macrophages, but did not significantly affect the ex vivo bactericidal capacity of cord blood MDM.

Maternal serum and breast milk vitamin D levels: findings from the Universiti Sains Malaysia Pregnancy Cohort Study

BACKGROUND

Vitamin D deficiency has become a global health issue in pregnant women. This study aimed to assess the adequacy of maternal vitamin D status by measuring maternal serum and breast milk 25-hydroxyvitamin D [25(OH)D] levels and to determine the association between maternal serum and milk 25(OH)D levels.

METHODS

Data was obtained from the Universiti Sains Malaysia Pregnancy Cohort Study. This study was conducted from April 2010 to December 2012 in the state of Kelantan, Malaysia. Blood samples from pregnant women aged 19 to 40 years were drawn in the second and third trimesters of pregnancy, while breast milk samples at delivery, 2, 6 and 12 months postpartum were collected to analyze for 25(OH)D levels. A total of 102 pregnant women were included in the analysis.

RESULTS

Vitamin D deficiency [25(OH)D <50 nmol/L] was detected in 60% and 37% of women in the second and third trimesters of pregnancy, respectively. There were 6% and 23% of women who reached normal level of vitamin D status in the second trimester and the third trimester, respectively. Multivitamin intakes during pregnancy were significantly associated with higher serum 25(OH)D levels in the second trimester (β = 9.16, p = 0.005) and the third trimester (β = 13.65, p = 0.003). 25(OH)D levels in breast milk during the first year of lactation ranged from 1.01 to 1.26 nmol/L. Higher maternal serum 25(OH)D level in the second trimester of pregnancy was associated with an elevated level of 25(OH)D in breast milk at delivery (β = 0.002, p = 0.026).

CONCLUSIONS

This study shows that high proportions of Malay pregnant women are at risk of vitamin D deficiency. Maternal vitamin D status in the second trimester of pregnancy was found to influence vitamin D level in breast milk at delivery.

Obstetric and neonatal outcomes of maternal vitamin D supplementation: results of an open-label, randomized controlled trial of antenatal vitamin D supplementation in Pakistani women

OBJECTIVE

The objective of the study was to determine whether vitamin D (vitD) supplementation during pregnancy affects obstetric and neonatal outcomes.

SETTING

The study was conducted at a university hospital in Karachi, Pakistan.

METHODS

The study was a single-center, open-label, randomized, controlled trial of routine care (group A, 200 mg ferrous sulfate and 600 mg calcium daily) vs vitD supplementation (group B, 4000 IU vitamin D3 daily), started at 20 weeks and continued till delivery. Maternal serum samples of 25-hydroxyvitamin D (25OHD) were collected at baseline and delivery. Neonatal vitD status was assessed in cord blood or in neonatal serum samples within 48 hours of birth. Obstetric outcomes included gestational hypertension, gestational diabetes, and preterm labor, and neonatal well-being included small for gestational age, birth weight, length, head circumference, and 1- and 5-minute Apgar scores.

RESULTS

Of 207 gravidae enrolled, 193 completed the trial. Maternal age, vitD status, and gestational age at enrollment were comparable between the two groups. At delivery, maternal 25OHD was increased in group B (18.3 ± 11 ng/dL vs 8.82 ± 11.84 ng/dL (P = .001) compared with group A (6.9 ± 7.0 ng/dL vs 6.32 ± 3.97 ng/dL, P = .06). The obstetric outcomes were comparable between the two groups (P > .05). Neonatal 25OHD levels were significantly higher in group B compared with group A (19.22 ± 12.19 ng/dL vs 6.27 ± 5.2 ng/dL). There was positive correlation between maternal and neonatal 25OHD levels (r = 0.83, P = .001). One- and 5-minute Apgar scores were significantly higher in group B (7.10 ± 0.66 vs 6.90 ± 0.50, P = .026, and 8.53 ± 0.68 vs 8.33 ± 0.81, P = .051, respectively). Neonatal anthropometric parameters were comparable between the two groups (P > .05).

CONCLUSION

Maternal vitD supplementation improved maternal and neonatal vitD status.

Maternal vitamin D status and infant outcomes in rural Vietnam: a prospective cohort study

Objective

Vitamin D deficiency affects 1 billion people globally. It has an important role in bone homeostasis, brain development and modulation of the immune system and yet the impact of antenatal vitamin D deficiency on infant outcomes is poorly understood. We assessed the association of 25- hydroxyvitamin D levels (25-OHD) in late pregnancy and early infant growth and developmental outcomes in rural Vietnam.

Design and Methods

A prospective cohort study of 960 women who had previously participated in a double-blind cluster randomized controlled trial of antenatal micronutrient supplementation in rural Vietnam was undertaken. Maternal 25-OHD concentration was measured at 32 weeks gestation, and infants were followed until 6 months of age. Main outcome measures were cognitive, motor, socio-emotional and language scores using the Bayley Scales of Infant Development, 3^rd edition, and infant length-for-age z scores at 6 months of age.

Results

60% (582/960) of women had 25-OHD levels <75 nmol/L at 32 weeks gestation. Infants born to women with 25-OHD deficiency (<37.5 nmol/L) had reduced developmental language scores compared to those born to women who were vitamin D replete (≥75 nmol/L) (Mean Difference (MD) −3.48, 95% Confidence Interval (CI) −5.67 to −1.28). For every 25 nmol increase in 25-OHD concentration in late pregnancy, infant length-for-age z scores at 6 months of age decreased by 0.08 (95% CI −0.15 to −0.02).

Conclusions

Low maternal 25- hydroxyvitamin D levels during late pregnancy are of concern in rural Vietnam, and are associated with reduced language developmental outcomes at 6 months of age. Our findings strengthen the evidence for giving vitamin D supplementation during pregnancy.

Mid-pregnancy vitamin D levels and postpartum depression

OBJECTIVES

Postpartum depression (PPD) is a common disorder that affects 10-15% of postpartum women, and it can have negative effects on both the mother and newborn. Recent studies have suggested that low levels of vitamin D are associated with poor mood and depression. The aim of this prospective study was to evaluate a possible association between PPD and serum levels of 25-hydroxy vitamin D3 (25(OH)D3), a reliable measurement of vitamin D, during mid-pregnancy.

STUDY DESIGN

The source population consisted of all pregnant women between 24 and 28 gestational weeks from June 2012 to October 2012 at Bornova Health Research and Application Hospital, Sifa University. In order to better evaluate a possible effect between vitamin D levels and PPD, individuals with characteristics that put them at risk for developing PPD were excluded from the study. Serum 25(OH)D3 levels were evaluated mid-pregnancy in the study group. Serum 25(OH)D3 concentrations ≤20ng/mL (50nmol/L) were classified as a mild deficiency and those ≤10ng/mL (25nmol/L) were classified as a severe deficiency. Pregnant subjects having complications during birth or with the newborn after delivery were excluded from the study. The Edinburgh Postnatal Depression Scale (EPDS) was used to assess maternal PPD 1 week, 6 weeks, and 6 months after delivery. A Pearson correlation was used to measure the strength of the associations between the EPDS scores and vitamin D levels analyzed during the three time periods. A logistic regression analysis was used to determine the independent effects of vitamin D on PPD.

RESULTS

Six hundred and eighty-seven pregnant women were included in this study. After excluding women due to PPD risk factors (in two stages), 179 pregnant women were screened for vitamin D levels during mid-pregnancy and in the 6th month postpartum. Eleven percent of our study group had severe vitamin D deficiency and 40.3% had mild vitamin D deficiency. The frequency of PPD was 21.6% at the 1st week, 23.2% at 6th week, and 23.7% at the 6th month. There was a significant relationship between low 25(OH)D3 levels in mid-pregnancy and high EPDS scores, which is indicative of PPD for all three follow-up periods (p=0.003, p=0.004 and p<0.001, respectively). In addition, there was a significant negative correlation between vitamin D levels and EDPS at all three time points (r=-0.2, -0.2, -0.3, respectively).

CONCLUSIONS

Vitamin D deficiency in mid-pregnancy may be a factor affecting the development of PPD. More extensive studies are required to be carried out on this subject.

Associations between 25-hydroxyvitamin D levels and pregnancy outcomes: a prospective observational study in southern China

BACKGROUND/OBJECTIVES

Observational studies relating 25-hydroxyvitamin D (25(OH)D) and pregnancy outcomes have reported conflicting results. The aim was to assess maternal 25(OH)D status and its association with pregnancy outcomes. A prospective observational study was carried out in Guangzhou city (23 ºN), China.

SUBJECTS/METHODS

Pregnant women (n=2960) and healthy controls (n=100) were recruited at a teaching hospital. Maternal 25(OH)D levels were measured at 16-20-week gestation. The pregnant women, if met inclusion and exclusion criteria, were enrolled in further analysis for pregnancy outcomes (n=1953).

RESULTS

Mean serum 25(OH)D in pregnant women was 27.03±7.92 ng/ml. In total, 18.9 and 48.6% of pregnant women had low (25(OH)D less than or equal to 20 ng/ml) and medium level (25(OH)D 21-29 ng/ml) of vitamin D, respectively. 25(OH)D was highest in summer and lowest in winter, which showed a positive correlation with temperature (R=0.942) and calcium (R=0.074). Most maternal outcomes (premature rupture of membranes break, polyhydramnios, oligohydramnios, pre-eclampsia, cesarean section), fetal outcomes (spontaneous abortions, medically induced labor, fetal death, fetal distress, fetal growth restriction) and neonatal outcomes (malformations, birth weight and height, low birth weight, macrosomia, small-for-gestational age, score of Apgar 1',5', asphyxia of newborn) were not significantly different between groups, but prevalence of gestational diabetes (adjusted odds ratio (OR) 1.017; 95% confidence interval (CI) 1.002-1.033) and preterm delivery (adjusted OR 1.038; 95% CI 1.018-1.059) in high level group (25(OH)D ⩾30 ng/ml) was higher than that in low and medium level groups.

CONCLUSIONS

The prevalence of low level of vitamin D (serum 25OHD ⩽20 ng/ml) was 18.9% among pregnant women in southern China. There were no significant differences in most adverse pregnancy outcomes among pregnant women with different levels of vitamin D at 16-20-week gestation except for higher prevalence of gestational diabetes and preterm delivery in women with high level of vitamin D, possibly related to the older age and higher body mass index of this group.

Antioxidant-rich dietary intervention for improving asthma control in pregnancies complicated by asthma: study protocol for a randomized controlled trial

Background

Asthma is the most prevalent chronic disease to complicate pregnancies worldwide, affecting around 12% of pregnant women in Australia. Oxidative stress and inflammation manifest during pregnancy; however asthma in pregnancies further intensifies oxidative stress. Consumption of antioxidant-rich foods has been shown to be beneficial for asthma control in non-pregnant asthmatic adults. It has not been investigated whether antioxidant-rich foods can improve the elevated oxidative stress that occurs with asthma in pregnancy, thereby improving asthma control. The primary aim of this study is to determine whether increased consumption of antioxidant-rich foods for 12 weeks will improve maternal asthma control, compared to standard dietary intake during pregnancy.

Methods/design

A 12 week, parallel randomized controlled trial will be conducted. One hundred and sixty eight pregnant women with mild, moderate, or severe asthma, currently using inhaled corticosteroids, and with poor diet quality, will be recruited at approximately12 weeks gestation. Following a 4 week run-in period, women will be randomized to either a 12 week antioxidant intervention (increased consumption of antioxidant-rich foods (≥5 servings/day vegetables, ≥2 servings/day fruit, ≥8 ½ servings/day grains (mostly wholegrains), 3–4 serving/week lean meat) or standard pregnancy care. The primary outcome is asthma control score (decrease of 0.5, the minimally clinically significant change). Secondary outcomes include plasma antioxidants, markers of oxidative stress, and time to, and number of, exacerbations. With two-tailed t-tests at 80% power, a sample size of 52 completions per group is required. Allowing for a 78% retention including a 20% removal of women from the analysis due to non-compliance, we will recruit 168 women.

Discussion

It is expected that this 12 week study will improve asthma control. This is significant because asthma is the most prevalent condition to complicate pregnancies and contributes to poor maternal, neonatal and infant health outcomes. Our research will provide the first evidence to show that, in pregnancy, consumption of antioxidant-rich foods is a key modifier of clinical asthma status. This research is crucial for contributing to the evidence base to inform future guidelines given existing clinical and research gaps.

Trial registration

ACTRN12613000301763

Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomised trials

OBJECTIVE

To evaluate the breadth, validity, and presence of biases of the associations of vitamin D with diverse outcomes.

DESIGN

Umbrella review of the evidence across systematic reviews and meta-analyses of observational studies of plasma 25-hydroxyvitamin D or 1,25-dihydroxyvitamin D concentrations and randomised controlled trials of vitamin D supplementation.

DATA SOURCES

Medline, Embase, and screening of citations and references.

ELIGIBILITY CRITERIA

Three types of studies were eligible for the umbrella review: systematic reviews and meta-analyses that examined observational associations between circulating vitamin D concentrations and any clinical outcome; and meta-analyses of randomised controlled trials assessing supplementation with vitamin D or active compounds (both established and newer compounds of vitamin D).

RESULTS

107 systematic literature reviews and 74 meta-analyses of observational studies of plasma vitamin D concentrations and 87 meta-analyses of randomised controlled trials of vitamin D supplementation were identified. The relation between vitamin D and 137 outcomes has been explored, covering a wide range of skeletal, malignant, cardiovascular, autoimmune, infectious, metabolic, and other diseases. Ten outcomes were examined by both meta-analyses of observational studies and meta-analyses of randomised controlled trials, but the direction of the effect and level of statistical significance was concordant only for birth weight (maternal vitamin D status or supplementation). On the basis of the available evidence, an association between vitamin D concentrations and birth weight, dental caries in children, maternal vitamin D concentrations at term, and parathyroid hormone concentrations in patients with chronic kidney disease requiring dialysis is probable, but further studies and better designed trials are needed to draw firmer conclusions. In contrast to previous reports, evidence does not support the argument that vitamin D only supplementation increases bone mineral density or reduces the risk of fractures or falls in older people.

CONCLUSIONS

Despite a few hundred systematic reviews and meta-analyses, highly convincing evidence of a clear role of vitamin D does not exist for any outcome, but associations with a selection of outcomes are probable.

Maternal vitamin D status and small-for-gestational-age offspring in women at high risk for preeclampsia

OBJECTIVE

To examine the association between second-trimester maternal serum 25-hydroxyvitamin D concentrations and risk of small for gestational age (SGA) in singleton live births.

METHODS

We assayed serum samples at 12-26 weeks of gestation for 25-hydroxyvitamin D in a sample of participants in a multicenter clinical trial of low-dose aspirin for the prevention of preeclampsia in high-risk women (n=792). Multivariable log-binomial regression models were used to assess the association between 25-hydroxyvitamin D and risk of SGA (birth weight less than the 10 percentile for gestational age) after adjustment for confounders including maternal prepregnancy obesity, race, treatment allocation, and risk group.

RESULTS

Thirteen percent of neonates were SGA at birth. Mean (standard deviation) 25-hydroxyvitamin D concentrations were lower in women who delivered SGA (57.9 [29.9] nmol/L) compared with non-SGA neonates (64.8 [29.3] nmol/L, P=.028). In adjusted models, 25-hydroxyvitamin D concentrations of 50-74 nmol/L and 75 nmol/L or greater compared with less than 30 nmol/L were associated with 43% (95% confidence interval [CI] 0.33-0.99) and 54% (95% CI 0.24-0.87) reductions in risk of SGA, respectively. Race and maternal obesity each modified this association. White women with 25-hydroxyvitamin D 50 nmol/L or greater compared with less than 50 nmol/L had a 68% reduction in SGA risk (adjusted risk ratio 0.32, 95% CI 0.17-0.63) and nonobese women with 25-hydroxyvitamin D 50 nmol/L or greater compared with less than 50 nmol/L had a 50% reduction in SGA risk (adjusted risk ratio 0.50, 95% CI 0.31-0.82). There was no association between 25-hydroxyvitamin D and risk of SGA in black or obese mothers.

CONCLUSION

Maternal vitamin D status in the second trimester is associated with risk of SGA among all women and in the subgroups of white and nonobese women.

LEVEL OF EVIDENCE

II.

Maternal-fetal-infant dynamics of the C3-epimer of 25-hydroxyvitamin D

BACKGROUND

Poor vitamin D status (i.e. low serum 25-hydroxyvitamin D (25(OH)D)) has been associated with adverse clinical outcomes during pregnancy and childhood. However, the interpretation of serum 25(OH)D levels may be complicated by the presence of the C3-epimer of 25(OH)D. We aimed to quantify C3-epi-25(OH)D3 in pregnant women and fetuses, to explore the relationship of the C3-epimer between maternal and cord samples, and to establish whether infant C3-epimer abundance is explained by prenatal formation.

METHODS

In a sub-study of a randomized trial of prenatal vitamin D3, 25(OH)D3 and C3-epi-25(OH)D3 were quantified by LC-MS/MS in 71 sets of mother-fetus-infant serum samples, including maternal delivery specimens, cord blood, and infant specimens acquired at 3-28 weeks of age.

RESULTS

Without supplementation, median concentrations of C3-epi-25(OH)D₃ were higher in infants (6.80 nmol/L) than mothers (0.45 nmol/L) and cord blood (0 nmol/L). However, there was substantial variation such that C3-epi-25(OH)D₃ accounted for up to 11% (maternal), 14% (cord), and 25% (infant) of the total 25(OH)D₃. Supplemental vitamin D₃ significantly increased maternal-fetal C3-epi-25(OH)D₃, and was a preferential source of C3-epi-25(OH)D₃ compared to basal vitamin D, possibly due to C3-epi-cholecalciferol in the supplement. Multivariate regression did not suggest transplacental transfer of C3-epi-25(OH)D₃, but rather indicated its generation within the fetal-placental unit from maternally-derived 25(OH)D₃. Neither maternal nor fetal C3-epi-25(OH)D₃ is accounted for the relatively high concentrations of infant C3-epi-25(OH)D₃, suggesting rapid postnatal generation.

CONCLUSIONS

C3-epi-25(OH)D₃ is present in some pregnant women and fetuses, but does not appear to be efficiently transferred transplacentally. High C3-epimer concentrations in infancy are probably due to postnatal formation rather than fetal stores.

Vitamin D and maternal and child health: overview and implications for dietary requirements

The essentiality of vitamin D for normal growth and development has been recognized for over 80 years, and vitamin D fortification programs have been in place in the United States for more than 70 years. Despite the above, vitamin D deficiency continues to be a common finding in certain population groups. Vitamin D deficiency has been suggested as a potential risk factor for the development of preeclampsia, and vitamin D deficiency during infancy and early childhood is associated with an increased risk for numerous skeletal disorders, as well as immunological and vascular abnormalities. Vitamin D deficiency can occur through multiple mechanisms including the consumption of diets low in this vitamin and inadequate exposure to environmental ultraviolet B rays. The potential value of vitamin D supplementation in high-risk pregnancies and during infancy and early childhood is discussed. Currently, there is vigorous debate concerning what constitutes appropriate vitamin D intakes during early development as exemplified by differing recommendations from the Institute of Medicine Dietary Reference Intake report and recent recommendations by the Endocrine Society. As is discussed, a major issue that needs to be resolved is what key biological endpoint should be used when making vitamin D recommendations for the pregnant woman and her offspring.

Maternal vitamin D levels during pregnancy and offspring eating disorder risk in adolescence

OBJECTIVE

To determine if maternal vitamin D concentrations at 18 weeks gestation predict offspring eating disorder risk in adolescence.

METHOD

Participants were 526 Caucasian mother-child dyads from the Western Australian Pregnancy Cohort (Raine) Study. The Raine Study has followed participants from 18 weeks gestation to 20 years of age. Maternal serum 25(OH)-vitamin D concentrations were measured at 18 weeks pregnancy and grouped into quartiles. Offspring eating disorder symptoms were assessed at ages 14, 17 and 20 years. Core analyses were limited to female offspring (n = 308).

RESULTS

Maternal 25(OH)-vitamin D quartiles were a significant predictor of eating disorder risk in female offspring, in multivariate logistic regression models. Vitamin D in the lowest quartile was associated with a 1.8-fold increase in eating disorder risk relative to concentrations in the highest quartile. This association also accounted for the relationship between offspring season of birth and eating disorder risk. Results were significant after adjusting for sociodemographic characteristics, body mass index and depressive symptoms.

DISCUSSION

This is the first study to link low gestational vitamin D to increased eating disorder risk in female offspring of Caucasian mothers. Research is needed to extend these findings and to consider how gestational vitamin D may relate to the pathogenesis of eating disorders.

Obesity and Vitamin D Deficiency - Current Concepts on their Impact on Pregnancy

Both obesity and vitamin D deficiency are linked to morbidity and ultimately mortality. Vitamin D sufficiency is believed to confer many health benefits; however, with the exception of the classic functions related to bone health these are not yet well understood, especially in relationship to pregnancy and infant health outcomes.1 Conversely, insufficiency is associated with adverse health outcomes, which are consequently related to public health concerns that arise from these and these need addressing.2,3 While the links between health and vitamin D are being considered and researched, there are an increasing number of reports that demonstrate vitamin D deficiency is prevalent particularly among people who are darker skinned, those who live at latitudes above 52°, and are therefore exposed to reduced sunlight especially in the autumn and winter months, those who through lifestyle choices cover their bodies, preventing sunlight exposure, and in obese people.3-6 Obesity is also of growing concern. Health journalists and academics sometimes dramatically refer to 'obesity epidemics,' which is not surprising as over one-third of Americans are obese.7-9 This problem, if not addressed, will lead to adverse health outcomes for individuals as well as being a long-term burden both to families and society.10-11 It is interesting to note that both vitamin D deficiency and obesity have shared risks for mortality and morbidity including cardiovascular disease, diabetes, respiratory problems, cancer and musculoskeletal disease. This paper considers current concepts and the links between obesity and vitamin D deficiency in pregnancy seeking to determine whether being vitamin D deficient and obese is simply double trouble, where both are present, or whether there are there other factors that need further exploration, reviewing the associated implications for practice.12-15.

Vitamin D for health: a global perspective

It is now generally accepted that vitamin D deficiency is a worldwide health problem that affects not only musculoskeletal health but also a wide range of acute and chronic diseases. However, there remains cynicism about the lack of randomized controlled trials to support the association studies regarding the nonskeletal health benefits of vitamin D. This review was obtained by searching English-language studies published up to April 1, 2013, in PubMed, MEDLINE, and the Cochrane Central Register of Controlled Trials (search terms: vitamin D and supplementation) and focuses on recent challenges regarding the definition of vitamin D deficiency and how to achieve optimal serum 25-hydroxyvitamin D concentrations from dietary sources, supplements, and sun exposure. The effect of vitamin D on fetal programming epigenetics and gene regulation could potentially explain why vitamin D has been reported to have such wide-ranging health benefits throughout life. There is potentially a great upside to increasing the vitamin D status of children and adults worldwide for improving musculoskeletal health and reducing the risk of chronic illnesses, including some cancers, autoimmune diseases, infectious diseases, type 2 diabetes mellitus, neurocognitive disorders, and mortality.

Associations between blood persistent organic pollutants and 25-hydroxyvitamin D3 in pregnancy

Persistent organic pollutants (POPs) are suggested to contribute to lower vitamin D levels; however, studies in humans are scarce and have never focused on pregnancy, a susceptibility period for vitamin D deficiency. We investigated whether serum levels of POPs were associated with circulating 25-hydroxyvitamin D3 [25(OH)D3] concentration in pregnancy. Cross-sectional associations of serum concentrations of eight POPs with plasma 25(OH)D3 concentration were analyzed in 2031 pregnant women participating in the Spanish population-based cohort INfancia y Medio Ambiente (INMA) Project. Serum concentrations of POPs were measured by gas chromatography and plasma 25(OH)D3 concentration was measured by high-performance liquid chromatography in pregnancy (mean 13.3±1.5weeks of gestation). Multivariable regression models were performed to assess the relationship between blood concentrations of POPs and 25(OH)D3. An inverse linear relationship was found between serum concentration of PCB180 and circulating 25(OH)D3. Multivariate linear regression models showed higher PCB180 levels to be associated with lower 25(OH)D3 concentration: quartile Q4 vs. quartile Q1, coefficient=-1.59, 95% CI -3.27, 0.08, p trend=0.060. A non-monotonic inverse relationship was found between the sum of predominant PCB congeners (PCB 180, 153 and 138) and 25(OH)D3 concentration: coefficient (95% CI) for quartile Q2 vs. Q1 [-0.50 (-1.94, 0.94)], quartile Q3 vs. Q1 [-1.56 (-3.11, -0.02)] and quartile Q4 vs. Q1 [-1.21 (-2.80, 0.38)], p trend=0.081. No significant associations were found between circulating 25(OH)D3 and serum levels of p,p'-DDE, p,p'-DDT, HCB, and ß-HCH. Our results suggest that the background exposure to PCBs may result in lower 25(OH)D3 concentration in pregnant women.

Vitamin D nutrition in pregnancy: current opinion

There is increasing interest in vitamin D nutrition during pregnancy because of widespread reports of a high prevalence of low vitamin D status in pregnant women. While vitamin D is important for calcium and phosphorus homeostasis and for bone health, it also plays important roles in many other physiologic functions in the body. Consistent with the expanded role of vitamin D, recent observational studies have demonstrated that low vitamin D status in pregnancy is associated with multiple potential adverse maternal, fetal, and infant outcomes and contributes to low vitamin D status in infants at birth. Therefore, an overview of the current understanding of vitamin D nutrition in pregnancy and a review of the results of studies to optimize vitamin D status during pregnancy and in the offspring is of public health importance and timely.

Randomized controlled trial (RCT) of vitamin D supplementation in pregnancy in a population with endemic vitamin D deficiency

BACKGROUND

Vitamin D (vD) deficiency in pregnancy is a global health problem and the amount of vD supplementation to prevent vD deficiency is controversial.

OBJECTIVE

The objective of the study was to determine effectiveness and safety of prenatal 2000 IU and 4000 IU/d compared with 400 IU/d vD3 supplementation in a randomized controlled trial in population in which vD deficiency is endemic.

DESIGN/METHODS

Arab women were randomized at 12-16 weeks of gestation to 400, 2000, and 4000 IU/d vD3, which were continued to delivery. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured during pregnancy and at delivery. The primary outcome was the maternal and cord blood 25(OH)D, and the secondary outcomes were the achievement of sufficient serum 25(OH)D of 32 ng/mL or greater (≥80 nmol/L) at delivery.

SETTING

The locations were primary care and tertiary perinatal care centers.

RESULTS

Of 192 enrolled, 162 (84%) continued to delivery. Mean serum 25(OH)D of 8.2 ng/mL (20.5 nmol/L) at enrollment was low. Mean serum 25(OH)D concentrations at delivery and in cord blood were significantly higher in the 2000 and 4000 IU than the 400 IU/d group (P < .001) and was highest in the 4000 IU/d group. The percent who achieved 25(OH)D greater than 32 ng/mL and greater than 20 ng/mL concentrations in mothers and infants was highest in 4000 IU/d group. Safety measurements were similar by group and no adverse event related to vD supplementation.

CONCLUSIONS

Vitamin D supplementation of 2000 and 4000 IU/d appeared safe in pregnancy, and 4000 IU/d was most effective in optimizing serum 25(OH)D concentrations in mothers and their infants. These findings could apply to other populations in which vD deficiency is endemic.

Parathyroid and calcium metabolism disorders during pregnancy

Parathyroid disorders are not common among pregnant women, but harbor a significant morbidity and mortality potential if they remain unrecognized and untreated. The symptoms caused by abnormally low or high blood free calcium level are mostly non-specific in the initial stages, thus when recognized might pose a real danger. Here we will survey the alterations in calcium metabolism induced by pregnancy, and describe the clinical manifestations, diagnosis and treatment of parathyroid and other calcium metabolism disorders during pregnancy. The current literature on the impact of calcium and vitamin D deficiency during pregnancy will also be reviewed.

To prevent the osteoporosis playing in advance

There are several possibilities for the prevention of primary, secondary and tertiary osteoporosis but till now they have not been promoted enough and bone fragility is thought about only after the onset of a fracture (tertiary prevention). By recent studies and discoveries it is becoming increasingly clear that there is a relationship between growth and development in early childhood and bone health in old age. Suboptimal bone development leads to a reduction in peak bone mass, and a higher risk of osteoporotic fracture later in life. Preventative strategies against osteoporosis can be aimed at either optimizing the peak bone mass obtained, or reducing the rate of bone loss. Optimization of peak bone mass may be more amenable to public health strategies. Technological advances and our knowledge of osteoporosis have increased in the last decade and so tertiary prevention should be considered a failure in the field of public health. If we want to make advances in the osteoporotic field, we must start in childhood, before the bone mass peak is reached and the gold-standard is starting with prevention as soon as possible, also during fetal development.

Randomized placebo-controlled trial of high-dose prenatal third-trimester vitamin D3 supplementation in Bangladesh: the AViDD trial

Background

Antenatal vitamin D status may be associated with the risk of adverse pregnancy and neonatal outcomes; however, the benefits of vitamin D supplementation during pregnancy remain unknown.

Methods

We conducted a double-blind placebo-controlled randomized trial to evaluate the effect of high-dose prenatal 3^rd trimester vitamin D3 supplementation on maternal and neonatal (cord blood) serum 25-hydroxyvitamin D (25(OH)D) concentration (primary biochemical efficacy outcome) and maternal serum calcium concentration (primary safety measure). Eligibility criteria were pregnant women aged 18 to <35 years, at 26 to 29 weeks gestation, and residing in Dhaka, Bangladesh. 160 women were randomized by 1:1 allocation to one of two parallel intervention groups; placebo (n = 80) or 35,000 IU/week of vitamin D3 (n = 80) until delivery. All participants, study personnel and study investigators were blind to treatment allocation.

Results

Mean maternal 25(OH)D concentration was similar in the vitamin D and placebo groups at baseline (45 vs. 44 nmol/L; p = 0.66), but was significantly higher in the vitamin D group vs. placebo group among mothers at delivery (134 vs. 38 nmol/L; p < 0.001) and newborns (cord blood: 103 vs. 39; p < 0.001). In the vitamin D group, 95% of neonates and 100% of mothers attained 25(OH)D >50 nmol/L, versus 21% mothers and 19% of neonates in the placebo group. No participants met criteria for hypercalcemia, there were no known supplement-related adverse events, and major pregnancy outcomes were similar between groups.

Conclusions

Antenatal 3^rd-trimester vitamin D3 supplementation (35,000 IU/week) significantly raised maternal and cord serum 25(OH)D concentrations above 50 nmol/L in almost all participants without inducing hypercalcemia or other observed safety concerns. Doses up to 35,000 IU/week may be cautiously used in further research aimed at establishing the clinical effects and safety of vitamin D3 supplementation in pregnancy.

Trial registration

This trial was registered at ClinicalTrials.gov (NCT01126528).

Maternal vitamin D status and adverse pregnancy outcomes: a systematic review and meta-analysis

OBJECTIVE

To estimate the associations between maternal vitamin D status and adverse pregnancy outcomes.

STUDY DESIGN

We searched electronic databases of the human literature in PubMed, EMBASE and the Cochrane Library up to October, 2012 using the following keywords: "vitamin D" and "status" or "deficiency" or "insufficiency" and "pregnancy". A systematic review and meta-analysis were conducted on observational studies that reported the association between maternal blood vitamin D levels and adverse pregnancy outcomes including preeclampsia, gestational diabetes mellitus (GDM), preterm birth or small-for-gestational age (SGA).

RESULTS

Twenty-four studies met the inclusion criteria. Women with circulating 25-hydroxyvitamin D [25(OH)D] level less than 50 nmol/l in pregnancy experienced an increased risk of preeclampsia [odds ratio (OR) 2.09 (95% confidence intervals 1.50-2.90)], GDM [OR 1.38 (1.12-1.70)], preterm birth [OR 1.58 (1.08-2.31)] and SGA [OR 1.52 (1.08-2.15)].

CONCLUSION

Low maternal vitamin D levels in pregnancy may be associated with an increased risk of preeclampsia, GDM, preterm birth and SGA.

Development and validation of a vitamin D status prediction model in Danish pregnant women: a study of the Danish National Birth Cohort

Vitamin D has been hypothesized to reduce risk of pregnancy complications such as preeclampsia, gestational diabetes mellitus, and preterm delivery. However, many of these outcomes are rare and require a large sample size to study, representing a challenge for cohorts with a limited number of preserved samples. The aims of this study were to (1) identify predictors of serum 25-hydroxy-vitamin D (25(OH)D) among pregnant women in a subsample (N = 1494) of the Danish National Birth Cohort (DNBC) and (2) develop and validate a score predicting 25(OH)D-status in order to explore associations between vitamin D and maternal and offspring health outcomes in the DNBC. In our study sample, 42.3% of the population had deficient levels of vitamin D (<50 nmol/L 25(OH)D) and average levels of 25(OH)D-status were 56.7(s.d. 24.6) nmol/L. A prediction model consisting of intake of vitamin D from diet and supplements, outdoor physical activity, tanning bed use, smoking, and month of blood draw explained 40.1% of the variance in 25(OH)D and mean measured 25(OH)D-level increased linearly by decile of predicted 25(OH)D-score. In total 32.2% of the women were placed in the same quintile by both measured and predicted 25(OH)D-values and 69.9% were placed in the same or adjacent quintile by both methods. Cohen's weighted kappa coefficient (Κ = 0.3) reflected fair agreement between measured 25(OH)D-levels and predicted 25(OH)D-score. These results are comparable to other settings in which vitamin D scores have shown similar associations with disease outcomes as measured 25(OH)D-levels. Our findings suggest that predicted 25(OH)D-scores may be a useful alternative to measured 25(OH)D for examining associations between vitamin D and disease outcomes in the DNBC cohort, but cannot substitute for measured 25(OH)D-levels for estimates of prevalence.

Maternal serum 25-hydroxyvitamin D and measures of newborn and placental weight in a U.S. multicenter cohort study

CONTEXT

Inconsistent associations between maternal vitamin D status and fetal size have been published in small studies.

OBJECTIVE

Our objective was to examine the association between maternal 25-hydroxyvitamin D [25(OH)D] levels and measures of newborn and placental weight.

DESIGN AND SETTING

We measured maternal 25(OH)D in mothers from the Collaborative Perinatal Project, an observational cohort conducted in 12 U.S. medical centers from 1959 to 1965.

PARTICIPANTS

Women delivering singleton, term, live births with 25(OH)D measured at a gestation of 26 wk or less (n = 2146).

MAIN OUTCOME MEASURES

Birth weight, ponderal index, placental weight, the placental to fetal weight ratio, and small for gestational age were measured. Hypotheses were formulated after data collection.

RESULTS

After confounder adjustment, mothers with 25(OH)D of 37.5 nmol/liter or greater gave birth to newborns with 46 g [95% confidence interval (CI), 9-82 g] higher birth weights and 0.13 cm (0.01-0.25 cm) larger head circumferences compared with mothers with less than 37.5 nmol/liter. Birth weight and head circumference rose with increasing 25(OH)D up to 37.5 nmol/liter and then leveled off (P < 0.05). No association was observed between 25(OH)D and ponderal index, placental weight, or the placental to fetal weight ratio. Maternal 25(OH)D of 37.5 nmol/liter or greater vs. less than 37.5 nmol/liter in the first trimester was associated with half the risk of small for gestational age (adjusted odds ratio 0.5; 95% CI 0.3-0.9), but no second-trimester association was observed.

CONCLUSIONS

Maternal vitamin D status is independently associated with markers of physiological and pathological growth in term infants. Adequately powered randomized controlled trials are needed to test whether maternal vitamin D supplementation may improve fetal growth.

Vitamin D levels in maternal serum and umbilical cord blood in a multi-ethnic population in Antwerp, Belgium



OBJECTIVE

To describe the status of vitamin D levels in maternal and umbilical cord blood in term pregnant woman in a mixed ethnic population in an inner-city European maternity.

METHODS

A single centre prospective cohort descriptive study including all uncomplicated singleton term pregnancies from April 1, 2011 until May 31, 2011. Plasma 25-hydroxy vitamin D level was determined in maternal and umbilical cord blood and data on age, previous obstetric history, ethnicity, nutritional intake and use of vitamin supplements were registered.

RESULTS

Complete data were collected in 94 patients. Mean maternal serum vitamin D was 16.6 ng/mL. Using a cut-off of 20 ng/mL, 66% of women were classified as deficient. Deficiency was present in all ethnic groups, but lower levels were noted in North-African, Central-African and Asian women. A strong correlation between maternal and umbilical cord levels was noted (R = 0.91). Number of previous pregnancies and intake of supplements had no influence.

CONCLUSION

The majority of low risk pregnant women showed vitamin D deficiency which was strongly correlated with umbilical cord levels. The prevalence was highest in the immigrant non-European population and was not influenced by intake of vitamin supplements. It can therefore be questioned whether the proposed cut-off values are appropriate.