The association of maternal vitamin D status with infant birth outcomes, postnatal growth and adiposity in the first 2 years of life in a multi-ethnic Asian population: the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort study

"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.

Does antenatal cholecalciferol supplementation affect the mode or timing of delivery? Post hoc analyses of the MAVIDOS randomized controlled trial

BACKGROUND

Observational studies relating maternal 25-hydroxyvitamin D status to timing and mode of delivery have reported inconsistent results. We assessed the effect of antenatal cholecalciferol supplementation on the incidence of preterm birth, delivery mode and post-partum haemorrhage (PPH).

METHODS

MAVIDOS was a randomized, double-blind, placebo-controlled trial of 1000 IU/day cholecalciferol from 14 weeks' gestation until delivery. Gestational age, mode of delivery [categorized as spontaneous vaginal delivery (SVD), instrumental (including forceps and vacuum extraction) or Caesarean section] and PPH (>500 ml estimated blood loss) were determined from medical records.

RESULTS

A total of 965 women participated in the study until delivery. Gestation at birth and incidence of preterm birth (cholecalciferol 5.7%, placebo 4.5%, P = 0.43) were similar between the two treatment groups. SVD (versus instrumental or Caesarean delivery) was more likely in women randomized to cholecalciferol [Relative Risk (RR) 1.13, 95% confidence interval (CI) 1.02,1.25] due to lower instrumental (RR 0.68, 95%CI 0.51,0.91) but similar risk of Caesarean delivery (RR 0.94, 95%CI 0.74,1.19). PPH was less common in women randomized to cholecalciferol [32.1% compared with placebo (38.1%, P = 0.054) overall], but similar when stratified by delivery mode.

CONCLUSIONS

Antenatal cholecalciferol supplementation did not alter timing of birth or prevalence of preterm birth but demonstrated a possible effect on the likelihood of SVD.

Time-to-conception and clinical pregnancy rate with a myo-inositol, probiotics, and micronutrient supplement: secondary outcomes of the NiPPeR randomized trial

OBJECTIVE

To determine whether a combined myo-inositol, probiotics and micronutrient nutritional supplement impacts time-to-natural-conception and clinical pregnancy rates.

DESIGN

Secondary outcomes of a double-blind randomized controlled trial.

SETTING

Community recruitment.

PATIENTS

Women aged 18 to 38 years planning to conceive in the United Kingdom, Singapore, and New Zealand, excluding those with diabetes mellitus or receiving fertility treatment.

INTERVENTION

A standard (control) supplement (folic acid, iron, calcium, iodine, β-carotene), compared with an intervention additionally containing myo-inositol, probiotics, and other micronutrients (vitamins B2, B6, B12, D, zinc).

MAIN OUTCOME MEASURES

Number of days between randomization and estimated date of natural conception of a clinical pregnancy, as well as cumulative pregnancy rates at 3, 6, and 12 months.

RESULTS

Of 1729 women randomized, 1437 (83%; intervention, n=736; control, n=701) provided data. Kaplan-Meier curves of conception were similar between intervention and control groups; the time at which 20% achieved natural conception was 90.5 days (95% confidence interval: 80.7, 103.5) in the intervention group compared with 92.0 days (76.0, 105.1) in the control group. Cox's proportional hazard ratios (HRs) comparing intervention against control for cumulative achievement of pregnancy (adjusted for site, ethnicity, age, body mass index, and gravidity) were similar at 3, 6, and 12 months. Among both study groups combined, overall time-to-conception lengthened with higher preconception body mass index, and was longer in non-White than in White women. Among women who were overweight the intervention shortened time-to-conception compared with control regardless of ethnicity (12-month HR=1.47 [1.07, 2.02], P=.016; 20% conceived by 84.5 vs. 117.0 days) and improved it to that comparable to nonoverweight/nonobese women (20% conceived by 82.1 days). In contrast, among women with obesity, time-to-conception was lengthened with intervention compared with control (12-month HR=0.69 [0.47, 1.00]; P=.053; 20% conceived by 132.7 vs. 108.5 days); an effect predominantly observed in non-White women with obesity.

CONCLUSIONS

Time-to-natural-conception and clinical pregnancy rates within a year were overall similar in women receiving the intervention supplement compared with control. Overweight women had a longer time-to-conception but there was suggestion that the supplement may shorten their time-to-conception to that comparable to the nonoverweight/nonobese women. Further studies are required to confirm this.

CLINICAL TRIAL REGISTRATION NUMBER

clinicaltrials.gov (NCT02509988).

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.

Correlation of Maternal Prenatal Vitamin D Level with Postnatal Infant Growth in Length and Head Circumference: A Cohort Study on Vitamin D Status and Its Impact During Pregnancy and Childhood in Indonesia

OBJECTIVE

To determine the correlation of first trimester maternal 25-(OH)-D level with postnatal infant growth in Indonesia.

MATERIALS AND METHODS

A cohort of 116 mother-infant pairs from Indonesia was prospectively studied. 25-(OH)-D level was measured in maternal serum at 10-14 weeks of gestation and in umbilical cord blood shortly after birth. The newborns were observed longitudinally for 24 months. Length and head circumference were measured at birth and at ages 3, 6, 12, and 24 months. Spearman correlation and multiple linear regression analyses were performed.

RESULTS

Mean 25-(OH)-D levels in the prenatal maternal serum and umbilical cord blood were 17.55 ± 7.33 ng/mL and 16.27 ± 6.14 ng/mL, respectively. Prenatal maternal 25-(OH)-D level weakly correlated with infant length (r = -0.35) and head circumference (r = -0.21) z-scores at age 3 months. Umbilical cord blood 25-(OH)-D level did not correlate with infant length or head circumference at any time point. Multiple linear regression showed an independent association between prenatal maternal 25-(OH)-D level and infant length z-score at age 3 months (p = 0.01, SE β = 0.02, and coefficient β = -0.06).

CONCLUSION

First trimester maternal serum 25(OH)D level correlated with infant length and head circumference at age 3 months.

Maternal and Neonatal Vitamin D Binding Protein Polymorphisms and 25-Hydroxyvitamin D Cutoffs as Determinants of Neonatal Birth Anthropometry

Background: Vitamin D-binding protein (VDBP) is a vital regulator of optimal vitamin D homeostasis and bioavailability. Apart from its well-documented role as a key component in vitamin D dynamic transfer and circulation, it has a myriad of immunoregulatory functions related to innate immunity, which becomes particularly critical in states of increased immunological tolerance including pregnancy. In this regard, VDBP dyshomeostasis is considered to contribute to the development of several fetal, maternal, and neonatal adverse outcomes. However, precise physiological pathways, including the contribution of specific VDBP polymorphisms behind such phenomena, are yet to be fully deciphered. Our aim was to assess the combined effect of maternal and neonatal VDBP polymorphism heterogeneity in conjunction with different maternal and neonatal 25(OH)D cutoffs on the neonatal anthropometric profile at birth. Methods: The study included data and samples from a cohort of 66 mother–child pairs at birth. The inclusion criterion was full-term pregnancy (gestational weeks 37–42). Neonatal and maternal 25(OH)D cutoffs were included according to vitamin D status at birth and delivery. Concentrations of 25(OH)D2 and 25(OH)D3 were measured using liquid chromatography–tandem mass spectrometry. Results: The upper arm length of neonates with 25(OH)D ≤ 25 nmol/L was higher in neonate CC carriers for rs2298850. The upper thigh neonatal circumference was also higher in the ones with either 25(OH)D ≤ 50 or ≤75 nmol/L in rs2298850 CG + GG or rs4588 GT + TT carriers. We did not observe any significant effect for maternal VDBP polymorphisms nor for birth maternal 25(OH)D concentrations, on birth neonatal anthropometry. Conclusions: Our findings emphasize a potential role for neonatal VDBP genotypes rs2298850 and rs4588, in conjunction with specific neonatal 25(OH)D cutoffs, in the range of sufficiency on neonatal growth and development.

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.

Impact of maternal hypovitaminosis D on birth and neonatal outcome - a prospective cohort study

OBJECTIVE

Vitamin D deficiency in pregnant women is of special concern as mother is the only source of vitamin D for the developing fetus, and maternal hypovitaminosis D has been implicated in a number of maternal and neonatal adverse outcomes. The objective of this study was to assess the association of maternal circulating 25-hydroxy vitamin D3 [25(OH)D] concentration with cord blood 25(OH)D and adverse birth and neonatal outcomes.

METHODS

This prospective cohort study was conducted in Mahatma Gandhi Medical College and Research Institute (MGMCRI) from January 2020 to December 2020. 121 babies born to mothers with singleton pregnancy tested for serum 25(OH)D level on admission for safe confinement were included in the study and cord blood of the babies were sampled for 25(OH)D. Based on the maternal 25(OH)D level, babies were categorized as those born to mothers with sufficient vitamin D level and those born to mothers with hypovitaminosis D (deficient/insufficient) and primary and secondary outcome was compared between two groups.

RESULTS

Maternal and cord blood hypovitaminosis D was observed in 65% of mothers and 68.6% of babies, respectively. Maternal vitamin D level was the single most significant predictor of cord blood vitamin D level with five-fold increased risk of cord blood hypovitaminosis D in babies born to mothers with hypovitaminosis D. Birthweight (t = -2.219, p = .028) and preterm birth (aOR = 4.417, 95% CI: 1.03-18.9) was significantly associated with maternal hypovitaminosis D and a trend toward increased risk of LBW (aOR - 2.1, 95%CI: 0.6-7.3), SGA babies (aOR - 1.5, 95% CI: 0.5-4.7), perinatal depression (aOR - 1.5, 95% CI: 0.4-5.8) and neonatal hyperbilirubinemia (aOR = 2.68, 95%CI: 0.942-7.6) was observed.

CONCLUSIONS

Hypovitaminosis D in pregnant women is a significant health issue affecting both the mother and her baby. Safest dose for supplementation during pregnancy to prevent adverse perinatal outcome needs to be evaluated.

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.

Effects of vitamin D on bone density in healthy children: A systematic review

Skeletal growth and bone health are very important in children. The effective role of vitamin D in bone mineral density has been observed in children and adolescents. This systematic review study evaluated the effects of vitamin D on bone density in healthy children with the help of valid databases and the website of clinical trials. The results of experimental, clinical, retrospective, prospective, double-blind, and randomized studies were used. Articles that appropriately covered the topic and had the proper content structure were selected for this review. Out of a total of 132 articles, finally, 13 articles were selected based on inclusion and exclusion criteria for further study, the results of which show the association between serum levels of vitamin D and bone mineral density and health. However, in some articles, the relationship between other influential variables such as age and nutrition on bone density in children was identified. In general, the current systematic review demonstrates the role of vitamin D on bone density in healthy children, so that in children studied, vitamin D is at different levels and complications related to bone density are observed in many children. It is recommended that more clinical and longitudinal studies be performed to further understand the role of vitamin D levels in bone health in children.

Interplay between Maternal and Neonatal Vitamin D Deficiency and Vitamin-D-Related Gene Polymorphism with Neonatal Birth Anthropometry

Vitamin D deficiency during pregnancy has been associated with poor foetal growth and neonatal birth anthropometry. However, the associations were inconsistent and could be confounded by neonatal vitamin D status and genetic factors. Until recently, limited studies have concomitantly examined the effect of maternal and neonatal vitamin D deficiency and vitamin D-related single nucleotide polymorphisms (SNPs) on neonatal birth anthropometry. This study aims to examine the independent and combined effects of maternal and neonatal vitamin D deficiency and vitamin-D-related SNPs on neonatal birth anthropometry. This cross-sectional study included 217 mother−neonate dyads recruited from Hospital Serdang, Selangor, Malaysia, between 2015 and 2017. Plasma 25-hydroxyvitamin D (25OHD) concentration was measured in maternal and umbilical cord blood using ultra-high-performance liquid chromatography (UHPLC). Maternal and neonatal vitamin D Receptor (VDR) SNP (rs2228570) genotypes were determined using high-resolution melting (HRM). Group-specific component (GC) SNPs (rs4588 and rs7041) genotypes were determined using restriction fragment length polymorphism. Our results showed that: (1) maternal vitamin D deficiency (25OHD < 30 nmol/L) was inversely associated with birth weight, head circumference and crown−heel length; (2) neonatal SNPs, VDR rs2228570 and GC rs4588, were significantly associated with birth weight and head circumference, respectively; and (3) a potential interaction was observed between maternal VDR rs2228570 with maternal vitamin D deficiency on head circumference. These findings suggest that the underlying mechanisms of vitamin D on foetal growth are likely to be localised in the maternal compartment, mediated through the placenta, rather than through cellular mechanisms within the foetus. Further large-scale studies are warranted to validate and extend these findings.

Variability in newborn telomere length is explained by inheritance and intrauterine environment

BACKGROUND

Telomere length (TL) and its attrition are important indicators of physiological stress and biological aging and hence may vary among individuals of the same age. This variation is apparent even in newborns, suggesting potential effects of parental factors and the intrauterine environment on TL of the growing fetus.

METHODS

Average relative TLs of newborns (cord tissue, N = 950) and mothers (buffy coat collected at 26-28 weeks of gestation, N = 892) were measured in a birth cohort. This study provides a comprehensive analysis of the effects of heritable factors, socioeconomic status, and in utero exposures linked with maternal nutrition, cardiometabolic health, and mental well-being on the newborn TL. The association between maternal TL and antenatal maternal health was also studied.

RESULTS

Longer maternal TL (β = 0.14, P = 1.99E-05) and higher paternal age (β = 0.10, P = 3.73E-03) were positively associated with newborn TL. Genome-wide association studies on newborn and maternal TLs identified 6 genetic variants in a strong linkage disequilibrium on chromosome 3q26.2 (Tag SNP-LRRC34-rs10936600: P_meta = 5.95E-08). Mothers with higher anxiety scores, elevated fasting blood glucose, lower plasma insulin-like growth factor-binding protein 3 and vitamin B12 levels, and active smoking status during pregnancy showed a higher risk of giving birth to offspring with shorter TL. There were sex-related differences in the factors explaining newborn TL variation. Variation in female newborn TL was best explained by maternal TL, mental health, and plasma vitamin B12 levels, while that in male newborn TL was best explained by paternal age, maternal education, and metabolic health. Mother's TL was associated with her own metabolic health and nutrient status, which may have transgenerational effects on offspring TL.

CONCLUSIONS

Our findings provide a comprehensive understanding of the heritable and environmental factors and their relative contributions to the initial setting of TL and programing of longevity in early life. This study provides valuable insights for preventing in utero telomere attrition by improving the antenatal health of mothers via targeting the modifiable factors.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT01174875. Registered on 1 July 2010.

Genetic Link Determining the Maternal-Fetal Circulation of Vitamin D

Vitamin D is an essential micronutrient whose demand is heightened during pregnancy to support the growth of the fetus. Furthermore, the fetus does not produce vitamin D and hence relies exclusively on the supply of maternal vitamin D through the placenta. Vitamin D inadequacy is linked with pregnancy complications and adverse infant outcomes. Hence, early predictive markers of vitamin D inadequacy such as genetic vulnerability are important to both mother and offspring. In this multi-ethnic Asian birth cohort study, we report the first genome-wide association analysis (GWAS) of maternal and fetal vitamin D in circulation. For this, 25-hydroxyvitamin D (25OHD) was measured in the antenatal blood of mothers during mid gestation (n=942), and the cord blood of their offspring at birth (n=812). Around ~7 million single nucleotide polymorphisms (SNPs) were regressed against 25OHD concentrations to identify genetic risk variants. About 41% of mothers had inadequate 25OHD (≤75nmol/L) during pregnancy. Antenatal 25OHD was associated with ethnicity [Malay (Β=−22.32nmol/L, p=2.3×10⁻²⁶); Indian (Β=−21.85, p=3.1×10⁻²¹); reference Chinese], age (Β=0.47/year, p=0.0058), and supplement intake (Β=16.47, p=2.4×10⁻¹³). Cord blood 25OHD highly correlated with antenatal vitamin D (r=0.75) and was associated with ethnicity [Malay (Β=−4.44, p=2.2×10⁻⁷); Indian (Β=−1.99, p=0.038); reference Chinese]. GWAS analysis identified rs4588, a missense variant in the group-specific component (GC) gene encoding vitamin D binding protein (VDBP), and its defining haplotype, as a risk factor for low antenatal (Β=−8.56/T-allele, p=1.0×10⁻⁹) and cord blood vitamin D (Β=−3.22/T-allele, p=1.0×10⁻⁸) in all three ethnicities. We also discovered a novel association in a SNP downstream of CYP2J2 (rs10789082), a gene involved in 25-hydroxylation of vitamin D, with vitamin D in pregnant women (Β=−7.68/G-allele, p=1.5×10⁻⁸), but not their offspring. As the prevention and early detection of suboptimal vitamin D levels are of profound importance to both mother and offspring’s health, the genetic risk variants identified in this study allow risk assessment and precision in early intervention of vitamin D deficiency.

Maternal vitamin D intake and BMI during pregnancy in relation to child's growth and weight status from birth to 8 years: a large national cohort study

OBJECTIVES

To examine the associations between maternal vitamin D intake and childhood growth and risk of overweight up to 8 years. We further examined the effect modification by maternal prepregnancy body mass index (BMI).

DESIGN

Prospective population-based pregnancy cohort study.

SETTING

The Norwegian Mother, Father and Child Cohort Study.

PARTICIPANTS

In total, 58 724 mothers and 66 840 singleton children, with information on maternal vitamin D intake during the pregnancy and minimum one postnatal anthropometric measurement.

OUTCOME MEASURES

Predicted weight and height growth trajectories and velocities from 1 month to 8 years, rapid growth during infancy and toddlerhood, and risk of overweight in preschool and school age.

RESULTS

Overall, maternal vitamin D intake was associated with lower weight trajectory, lower odds of rapid weight growth and higher odds of childhood overweight. In children of mothers with prepregnancy normal weight, maternal vitamin D intake was negatively associated with weight trajectory and lower OR of a rapid weight growth during the first year, compared with reference (<5 µg/day). Children of mothers with normal weight, with maternal vitamin D intakes of 10-15 and >15 µg/day, also had 0.86 (95% CI 0.77 to 0.97) and 0.88 (95% CI 0.79 to 0.99) lower odds for overweight at 3 years, compared with reference. In contrast, in children of mothers with prepregnancy overweight (BMI ≥25 kg/m²), vitamin D intake was positively associated with weight trajectory. Children of mothers with overweight, with maternal vitamin D intake of 5-9.9 µg/day, also had (1.09 (95% CI 1.01 to 1.18) and 1.12 (95% CI 1.02 to 1.23)) higher odds for overweight at 5 years and 8 years, compared with reference.

CONCLUSIONS

Maternal vitamin D intake affects postnatal growth and is inversely associated with childhood overweight in children of mothers with normal weight. Associations between maternal vitamin D intake and child growth and risk of overweight varied by prepregnancy BMI.

Increasing nausea and vomiting of pregnancy is associated with sex-dependent differences in early childhood growth: the GUSTO mother-offspring cohort study

BACKGROUND

Nausea and vomiting of pregnancy (NVP) is common and underlying mechanisms are poorly understood. Longer-term offspring outcomes are also not well documented. This study aimed to determine if NVP, even in milder forms, is associated with adverse pregnancy and childhood growth outcomes.

METHODS

In the GUSTO prospective mother-offspring cohort, women with singleton pregnancies (n = 1172) recruited in first trimester responded to interviewer-administered questions at 26-28 weeks' gestation about earlier episodes of NVP since becoming pregnant. Pregnancy outcomes were obtained from medical records. Offspring height and weight measured at 15 time-points between birth to 72 months (m) were standardised for age and sex.

RESULTS

58.5% (n = 686) reported mild-moderate vomiting (mNVP), 10.5% (n = 123) severe vomiting (sNVP) and 5.7% (n = 67) severe vomiting with hospitalisation (shNVP). There was no difference in odds of gestational diabetes, hypertensive disorders of pregnancy, labour induction or caesarean section after adjustment for covariates. sNVP was associated with late preterm delivery [34+ 0-36+ 6 weeks', adjusted OR = 3.04 (95% CI 1.39,6.68)], without increased odds of neonatal unit admission. Compared with no NVP, boys born to mothers with sNVP were longer at birth [adjusted β = 0.38 standard deviations (SDs) (95% CI 0.02,0.73)], remained taller [0.64 SDs (0.23,1.04) at 72 m] and heavier [0.57 SDs (0.05,1.08) at 60 m] without differences in BMI. Conversely, girls born to mothers with shNVP were lighter from 48 m [- 0.52 SDs (- 1.00, - 0.03)] onwards with lower BMI [- 0.61 SDs (- 1.12,-0.09)]. Conditional growth modelling revealed significant sex-divergence in weight-gain at birth-3 m, 6-9 m and 4-5 years.

CONCLUSIONS

Severe NVP was associated with late preterm delivery, and both mild-moderate and severe NVP associated with sex-dependent differences in early childhood growth. Boys whose mothers had NVP were taller and heavier from birth with faster growth in the first year, whereas, girls had poorer weight gain and were lighter by 48 m. As even milder severities of NVP could have long-term impact on offspring growth, further research is needed to determine mechanisms involved and implications on future health.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT01174875 .

Systematic review and meta-analysis of vitamin D deficiency in different pregnancy on preterm birth: Deficiency in middle pregnancy might be at risk

BACKGROUND

Current studies suggest that vitamin D deficiency during pregnancy can produce a certain effect for preterm birth (PTB), but there is no research showing whether vitamin D deficiency has a consistent effect in different pregnancies; thus, we conducted a systematic review and meta-analysis of 24 observational studies, grouping them according to the gestational age at the time of serum sampling, to investigate whether vitamin D deficiency in different periods of gestation has different effects on PTB and to provide an evidence-based basis for pregnant women to measure and supplement vitamin D.

METHODS

The databases PubMed-Medline, EMBASE, the Cochrane Library, Web of Science, EBSCO, CBM, and CNKI were searched until February 2020. Two researchers independently assessed the eligibility and quality of studies, and STATA 12.0 software was used for meta-analysis.

RESULT

Seven cohort studies, 13 case-control studies, and 4 cross-sectional studies were included from 2500 articles by inclusion and exclusion criteria. After adjusting for age, race, and other confounding factors, meta-analysis results showed that vitamin D deficiency in the first trimester, the second trimester, and the third trimester did not increase the risk of PTB (odds ratio (OR) = 1.01, 95% confidence interval (CI) (0.88, 1.16), P = .867; OR = 1.12, 95%CI (0.92, 1.37), P = .249; OR = 1.05, 95%CI (0.87, 1.27), P = .602). However, there was moderate heterogeneity in the study of vitamin D deficiency in the second trimester, and subgroup analysis suggested that vitamin D deficiency in the second trimester may increase the risk of PTB (OR = 1.33, 95%CI (1.15, 1.54), P = .000). A sensitivity analysis of the second trimester showed that excluding any 1 study did not significantly change the results.

CONCLUSIONS

Vitamin D deficiency in early and late pregnancy may not be associated with PTB, while vitamin D deficiency in middle pregnancy is likely to have an important effect on PTB. Vitamin D levels should be measured in the second trimester of pregnancy, and vitamin D supplements should be provided if necessary.

Association of vitamin D and gene variants in the vitamin D metabolic pathway with preterm birth

OBJECTIVES

The aim of this study was to explore the association of vitamin D (VitD) levels during pregnancy and its metabolic pathway genes with the risk for preterm birth (PTB) among pregnant women in southeast China.

METHODS

This study was conducted in Zhoushan Maternal and Child Health Hospital, Zhejiang, from August 2011 to May 2018. Plasma 25-hydroxyvitamin vitamin D [25(OH)D] levels in three trimesters and single-nucleotide morphisms in the VitD metabolic pathway were measured. Relevant information was collected using questionnaires and an electronic medical recorder system. Multiple statistical methods including linear regression, logistic regression, and crossover analysis were applied.

RESULTS

The prospective cohort study included 3465 pregnant women, of which 202 were PTB (week of gestation at delivery: 33.38 ± 4.05), accounting for 5.8%. After adjusting for potential confounders, VitD sufficiency (≥30 ng/mL) in the second and third trimesters was associated with longer gestational age at delivery compared with VitD deficiency (<20 ng/mL). However, no significant association was found between VitD with the risk for PTB. rs7041, rs10210408, and rs2228171 were associated with gestational week and the risk for PTB. Significant associations were found of rs10210408, rs2209314, rs1155563, rs2544381 and the status of VitD in the second and third trimester with the gestational week. We also found that rs7041 and VitD in the second trimester might exert interaction on gestational week and the risk for PTB (P_inter = 0.038; P_inter = 0.019); rs16846876 and VitD in the second trimester might exert interaction on gestational week (P_inter = 0.024); rs4334089 and VitD in the third trimester might exert interaction on gestational week (P_inter = 0.024). Similar results were found when we tested pregnant women's plasma 25(OH)D in the first and second trimesters.

CONCLUSIONS

Women with VitD deficiency were associated with shorter gestational weeks. Single-nucleotide morphisms in VitD metabolic pathway genes were significantly associated with gestation week and the risk for PTB, mainly in vitamin D-binding protein (GC) and low-density lipoprotein-related protein 2 (LRP2)genes. Additionally, maternal VitD with GC gene and maternal VitD with vitamin D receptor (VDR) gene might exert interactions on the risk for PTB.

The Effects of Vitamin D Supplementation During Infancy on Growth During the First 2 Years of Life

CONTEXT

The relationship between maternal and infant vitamin D and early childhood growth remains inadequately understood.

OBJECTIVE

This work aimed to investigate how maternal and child 25-hydroxyvitamin D (25[OH]D) and vitamin D supplementation affect growth during the first 2 years of life.

METHODS

A randomized, double-blinded, single-center intervention study was conducted from pregnancy until offspring age 2 years. Altogether 812 term-born children with complete data were recruited at a maternity hospital. Children received daily vitamin D3 supplementation of 10 μg (group 10) or 30 μg (group 30) from age 2 weeks to 2 years. Anthropometry and growth rate were measured at age 1 and 2 years.

RESULTS

Toddlers born to mothers with pregnancy 25(OH)D greater than 125 nmol/L were at 2 years lighter and thinner than the reference group with 25(OH)D of 50 to 74.9 nmol/L (P < .010). Mean 2-year 25(OH)D concentrations were 87 nmol/L in group 10 and 118 nmol/L in group 30 (P < .001). When group 30 was compared with group 10, difference in body size was not statistically significant (P > .053), but group 30 had slower growth in length and head circumference between 6 months and 1 year (P < .047), and more rapid growth in weight and length-adjusted weight between 1 and 2 years (P < .043). Toddlers in the highest quartile of 25(OH)D (> 121 nmol/L) were shorter (mean difference 0.2 SD score [SDS], P = .021), lighter (mean difference 0.4 SDS, P = .001), and thinner (in length-adjusted weight) (mean difference 0.4 SDS, P = .003) compared with the lowest quartile (< 81.2 nmol/L).

CONCLUSION

Vitamin D and early childhood growth may have an inverse U-shaped relationship.

Maternal vitamin D deficiency increases the risk of obesity in male offspring mice by affecting the immune response

OBJECTIVES

Recently, many epidemiologic and animal studies have indicated that obesity has its origin in early stages of life, including the inappropriate balance of some nutrients. So the objectives of this study were to determine the risk of obesity in male offspring mice as a consequence of maternal vitamin D (VD) deficiency mediating the disordered immune response.

METHODS

C57BL/6J female mice 4 wk old were fed VD-deficient or normal reproductive diets during pregnancy and lactation. Their male offspring were given control and high-fat diets for 16 wk after weaning and then weighed and euthanized. The serum was collected for biochemical analyses. Epididymal (eWAT) and inguinal white adipose tissue (iWAT) were excised for histologic examination, immunohistochemistry, gene expression of inflammatory factors, and determination by flow cytometry of the proportions of immune cells.

RESULTS

Insufficient maternal VD intake exacerbated the development of obesity in male offspring mice that were both obese and non-obese, as evidenced by larger adipose cells and abnormal glucose and lipid metabolisms. Also, the expressions of proinflammatory cytokines were increased and that of anti-inflammatory cytokines was decreased in eWAT and/or iWAT in the maternal VD-deficient group, accompanied by higher levels of tumor necrosis factor-α and/or interferon-γ and lower levels of interleukin-4 and interleukin-10. Insufficient maternal VD intake was also observed to induce a shift in the profiles of immune cells in the eWAT and/or iWAT of male offspring that were both obese and non-obese, resulting in increased percentages of M1 macrophages, adipose tissue dendritic cells, and CD4⁺ and CD8⁺ T cells but a significant decrease in the percentages of M2 macrophages. All these changes in the immune cell profile were more obvious in the eWAT than those in the iWAT.

CONCLUSIONS

Maternal VD deficiency might promote the development of obesity in male offspring mice partly by modulating the immune cell populations and causing a polarization in the adipose depots.

First trimester maternal vitamin D, ferritin, hemoglobin level and their associations with neonatal birthweight: Result from cohort study on vitamin D status and its impact during pregnancy and childhood in Indonesia

INTRODUCTION

Vitamin D deficiency and anemia are examples of nutritional problems of global health significance. When these health issues effect pregnant women, they may become a threat to the fetus' potention for intrauterine growth. It has been known that the first trimester is the golden period of fetal programming which influences the fetuses and their life after birth. This study was aiming to analyze the association between first trimester maternal vitamin D, serum ferritin, hemoglobin level and neonatal birth weight.

METHODS

From July 2016 a prospective cohort of pregnant women had been observed in four cities in West Java, Indonesia. Two hundred ninety four pregnant women were recuited in the first trimester and 203 of them had complete follow up until delivery. Collected data included maternal demography, blood analysis for ferritin, 25(OH) vitamin D in the first trimester of pregnancy and the birth weight of neonates. Associations were analyzed with multiple regression models.

RESULTS

Vitamin D deficiency was highly prevalent among pregnant women in this study (approximately 75%) while anemia was found in 7.5 %, a little above the target of 5 %. However, no significant association was found between maternal serum vitamin D, serum ferritin, hemoglobin level in the first trimester and birth weight of the neonates, before and after adjustment for maternal age, pre-pregnancy body mass index, and parity.

CONCLUSION

There were no associations found between vitamin D, ferritin, and hemoglobin level in the first trimester and neonatal birth weight. The negative results in this study should not diminish the benefit of nutritional supplementation during pregnancy. The possibility of other explanatory variables that influence these associations warrants further studies.

Correlation between maternal and neonatal blood Vitamin D level: Study from Pakistan

In Pakistan, there is limited evidence for the levels and relationship of 25 (OH) Vitamin D (25(OH)D) status in pregnant women and their newborns, while the association between maternal 25(OH)D and newborn anthropometric measurements remains unexplored. Sociodemographic data were collected from 213 pregnant mothers during their visit to a tertiary care hospital at the time of childbirth. Anthropometric measurements were performed on all mothers and their newborns and blood samples collected from both for 25(OH)D levels. Participants were classified into two groups according to their 25(OH)D status: sufficient (25(OH)D ≥50 nmol L-1 ) and deficient (25(OH)D <50 nmol L-1 ). Simple and multiple regression models were used for analysis. Among 213 pregnant women, prevalence of 25(OH)D deficiency was 61.5%, and their newborn was 99.5% (mean 25(OH)D levels: 46.3 [11.3] and 24.9 [5.4] nmol L-1 , respectively). Maternal sociodemographic characteristics were similar between 25(OH)D deficient and sufficient mothers, whereas newborn 25(OH)D levels were significantly lower in the former (22.60 [4.53] vs. 27.67 [3.82] nmol L-1 , respectively, P < 0.001). There was a strong positive association between maternal and newborn 25(OH)D levels (r, 0.66; r2 , 43%, B [SE], 0.3 [0.02]; P < 0.001). Association of maternal 25(OH)D levels with newborn weight, length and head circumference was not significant (all P > 0.05). Our study shows a high prevalence of 25(OH)D deficiency in pregnant women and their newborns and a strong positive association between maternal and newborn 25(OH)D levels. Findings of this study indicate the importance of maintaining sufficient 25(OH)D levels during pregnancy.

Multiple modifiable lifestyle factors and the risk of perinatal depression during pregnancy: Findings from the GUSTO cohort

BACKGROUND

Studies have identified lifestyle risk factors for perinatal depression, but none have examined the cumulative effect of these risk factors in pregnant women.

METHODS

We considered the following six factors during pregnancy: poor diet quality (Healthy eating index for Singapore pregnant women<median), poor sleep quality (global Pittsburgh sleep quality index score > 5), physical inactivity (<600 MET-minutes/week), vitamin D insufficiency (<50 nmol/l), smoking before or during pregnancy, and the perceived need for social support. Probable depression was assessed using the Edinburgh postnatal depression scale during pregnancy (>15) and at three months postpartum (≥13). Prevalence risk ratios were calculated with Poisson regressions while adjusting for potential confounders.

RESULTS

Of 535 pregnant women, 207 (39%) had zero or one risk factor, 146 (27%) had two, 119 (22%) had three, 48 (9%) had four, and 15 (3%) had ≥5 risk factors at 26-28 weeks' gestation. These six lifestyle habits contributed to 32% of the variance in depressive symptoms during pregnancy. The prevalence of being probably depressed was 6.4 (95% CI 2.1, 19.8; p_trend < 0.001) for expecting women who had ≥4 risk factors compared to women who had ≤1 risk factor. No association was observed between the number of risk factors and depressive symptoms at 3 months postpartum (p_trend = 0.746).

CONCLUSION

Pregnant women with ≥4 lifestyle risk factors showed a higher prevalence of depression during pregnancy, while no associations were observed for postpartum depression.

CLINICAL TRIAL REGISTRATION

This cohort is registered under the Clinical Trials identifier NCT01174875; http://www.clinicaltrials.gov/ct2/show/NCT01174875?term=GUSTO&rank=2.

The association between maternal fat-soluble vitamin concentrations during pregnancy and infant birth weight in China

Fat-soluble vitamins during pregnancy are important for fetal growth and development. The present study aimed at exploring the association between vitamin A, E and D status during pregnancy and birth weight. A total of 19 640 women with singleton deliveries from a retrospective study were included. Data were collected by the hospital electronic information system. Maternal serum vitamin A, E and D concentrations were measured during pregnancy. Logistic regression was performed to estimate the association between the vitamin status and low birth weight (LBW) or macrosomia. Women with excessive vitamin E were more likely to have macrosomia (OR 1·30, 95 % CI 1·07, 1·59) compared with adequate concentration. When focusing on Z scores, there was a positive association between vitamin E and macrosomia in the first (OR 1·07, 95 % CI 1·00, 1·14), second (OR 1·27, 95 % CI 1·11, 1·46) and third (OR 1·28, 95 % CI 1·06, 1·54) trimesters; vitamin A was positively associated with LBW in the first (OR 1·14, 95 % CI 1·01, 1·29), second (OR 1·31, 95 % CI 1·05, 1·63) and third (OR 2·00, 95 % CI 1·45, 2·74) trimesters and negatively associated with macrosomia in the second (OR 0·79, 95 % CI 0·70, 0·89) and third (OR 0·77, 95 % CI 0·62, 0·95) trimesters. The study identified that high concentrations of vitamin E are associated with macrosomia. Maintaining a moderate concentration of vitamin A during pregnancy might be beneficial to achieve optimal birth weight. Further studies to explore the mechanism of above associations are warranted.

The role of parathyroid hormone during pregnancy on the relationship between maternal vitamin D deficiency and fetal growth restriction: a prospective birth cohort study

Previous studies have shown conflicting findings regarding the relationship between maternal vitamin D deficiency (VDD) and fetal growth restriction (FGR). We hypothesised that parathyroid hormone (PTH) may be an underlying factor relevant to this potential association. In a prospective birth cohort study, descriptive statistics were evaluated for the demographic characteristics of 3407 pregnancies in the second trimester from three antenatal clinics in Hefei, China. The association of the combined status of vitamin D and PTH with birth weight and the risk of small for gestational age (SGA) was assessed by a multivariate linear and binary logistic regression. We found that declined status of 25-hydroxyvitamin D is associated with lower birth weight (for moderate VDD: adjusted β = -49·4 g, 95 % CI -91·1, -7·8, P < 0·05; for severe VDD: adjusted β = -79·8 g, 95 % CI -127·2, -32·5, P < 0·01), as well as ascended levels of PTH (for elevated PTH: adjusted β = -44·5 g, 95 % CI -82·6, -6·4, P < 0·05). Compared with the non-VDD group with non-elevated PTH, pregnancies with severe VDD and elevated PTH had the lowest neonatal birth weight (adjusted β = -124·7 g, 95 % CI -194·6, -54·8, P < 0·001) and the highest risk of SGA (adjusted risk ratio (RR) = 3·36, 95 % CI 1·41, 8·03, P < 0·01). Notably, the highest risk of less Ca supplementation was founded in severe VDD group with elevated PTH (adjusted RR = 4·67, 95 % CI 2·78, 7·85, P < 0·001). In conclusion, elevated PTH induced by less Ca supplementation would further aggravate the risk of FGR in pregnancies with severe VDD through impaired maternal Ca metabolism homoeostasis.

Vitamin D, and Maternal and Child Health

Vitamin D has important roles in calcium metabolism and in the prevention of rickets and osteomalacia; low levels of 25-hydroxyvitamin D are common in the general population and amongst pregnant women. Whilst there is a wealth of observational evidence linking vitamin D deficiency to a wide range of disease outcomes, there are currently few high-quality randomised controlled trials to confirm any causal associations, although many are currently in progress. Furthermore, currently, the vast majority of published guidelines recommend standard supplemental vitamin D doses for children and pregnant women, yet there is increasing recognition that individual characteristics and genetic factors may influence the response to supplementation. As such, future research needs to concentrate on documenting definite beneficial clinical outcomes of vitamin D supplementation, and establishing personalised dosing schedules and demonstrating effective approaches to optimising initiation and adherence.

Maternal and child factors associated with bone length traits in children at 3 years of age

BACKGROUND

Exposure to sub-optimal maternal vitamin D status during pregnancy has been linked to inadequate in utero bone growth with potential for post-natal deficits, but reported findings are inconsistent. Possible reasons include measurement error in assessing bone length/height, or lack of adjustment for confounding variables such as maternal/infant diet, physical activity and season of birth. The objective of this study was to determine the maternal and child factors associated with bone length traits in children at 3 years of age as part of a longitudinal follow-up of a pregnancy cohort.

METHODS

Mother-child dyads enrolled in the Family Atherosclerosis Monitoring In early Life study were included. Maternal serum 25-hydroxyvitamin D (25(OH)D) concentration was measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). Anthropometry, physical activity by questionnaire and dietary assessment by food frequency questionnaire were completed for mothers during pregnancy (27-40 weeks gestation) and for children at 3 years with diet by 3-day food records (Nutritionist Pro). Whole body bone mineral density in mother and child (n = 473) was measured by dual-energy absorptiometry (DXA) at the 3 year visit. A software program was developed using MATLAB to derive bone length measurements from whole body DXA images using 8 long bones of each child. Association between maternal and child variables with offspring bone length was assessed using unadjusted and adjusted multivariate linear regression analyses.

RESULTS

In the final adjusted multivariate regression model, factors associated with child bone length were maternal height (p = 0.05), child birth length (p = 0.005) and child weight z-score at 3 years (p < 0.001). No association was observed between maternal serum 25(OH)D concentrations in pregnancy (of which 77% were in normal range) and child bone length.

CONCLUSION

In healthy Canadian mothers and their children, the factors associated with child bone length achieved at 3 years of age appear to be related to genetic traits rather than environmental exposures. Measures of the length of long bones in children using DXA scans may have provided a more accurate assessment of bone length than whole body height measures.

Examining the predictive accuracy of metabolomics for small-for-gestational-age babies: a systematic review

INTRODUCTION

To date, there is no robust enough test to predict small-for-gestational-age (SGA) infants, who are at increased lifelong risk of morbidity and mortality.

OBJECTIVE

To determine the accuracy of metabolomics in predicting SGA babies and elucidate which metabolites are predictive of this condition.

DATA SOURCES

Two independent researchers explored 11 electronic databases and grey literature in February 2018 and November 2018, covering publications from 1998 to 2018. Both researchers performed data extraction and quality assessment independently. A third researcher resolved discrepancies.

STUDY ELIGIBILITY CRITERIA

Cohort or nested case-control studies were included which investigated pregnant women and performed metabolomics analysis to evaluate SGA infants. The primary outcome was birth weight <10th centile-as a surrogate for fetal growth restriction-by population-based or customised charts.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two independent researchers extracted data on study design, obstetric variables and sampling, metabolomics technique, chemical class of metabolites, and prediction accuracy measures. Authors were contacted to provide additional data when necessary.

RESULTS

A total of 9181 references were retrieved. Of these, 273 were duplicate, 8760 were removed by title or abstract, and 133 were excluded by full-text content. Thus, 15 studies were included. Only two studies used the fifth centile as a cut-off, and most reports sampled second-trimester pregnant women. Liquid chromatography coupled to mass spectrometry was the most common metabolomics approach. Untargeted studies in the second trimester provided the largest number of predictive metabolites, using maternal blood or hair. Fatty acids, phosphosphingolipids and amino acids were the most prevalent predictive chemical subclasses.

CONCLUSIONS AND IMPLICATIONS

Significant heterogeneity of participant characteristics and methods employed among studies precluded a meta-analysis. Compounds related to lipid metabolism should be validated up to the second trimester in different settings.

PROSPERO REGISTRATION NUMBER

CRD42018089985.

Developmental Programming of Body Composition: Update on Evidence and Mechanisms

PURPOSE OF REVIEW

A growing body of epidemiological and experimental data indicate that nutritional or environmental stressors during early development can induce long-term adaptations that increase risk of obesity, diabetes, cardiovascular disease, and other chronic conditions-a phenomenon termed "developmental programming." A common phenotype in humans and animal models is altered body composition, with reduced muscle and bone mass, and increased fat mass. In this review, we summarize the recent literature linking prenatal factors to future body composition and explore contributing mechanisms.

RECENT FINDINGS

Many prenatal exposures, including intrauterine growth restriction, extremes of birth weight, maternal obesity, and maternal diabetes, are associated with increased fat mass, reduced muscle mass, and decreased bone density, with effects reported throughout infancy and childhood, and persisting into middle age. Mechanisms and mediators include maternal diet, breastmilk composition, metabolites, appetite regulation, genetic and epigenetic influences, stem cell commitment and function, and mitochondrial metabolism. Differences in body composition are a common phenotype following disruptions to the prenatal environment, and may contribute to developmental programming of obesity and diabetes risk.

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

OBJECTIVE

The object of the present study was to estimate the relationship between maternal vitamin D deficiency during pregnancy and low birth weight by systematically review prevalence studies.

METHODS

We collected data from relevant studies published up to April 2019 using predefined inclusion/exclusion criteria. And all the studies were searched in PubMed, Embase, Cochrane Library, and Web of Science.

RESULTS

A total of 16 studies met the criteria and were included in the meta-analysis. When compared with normal serum levels of vitamin D, the maternal vitamin D deficiency had an increased risk of low birth weight (OR = 2.39; 95%CI 1.25-4.57; p = .008), and same results were found in the comparison of the mean (the total mean birth weight decreased by 0.08 kg; 95%CI -0.10 to -0.06; p < .001).

CONCLUSION

The evidence from this meta-analysis indicates a consistent association between vitamin D deficiency during pregnancy and an increased risk of low birth weight, and preventing maternal vitamin D deficiency may be an important public health strategy to help decrease the risk of low birth weight.

Association of first trimester maternal vitamin D, ferritin and hemoglobin level with third trimester fetal biometry: result from cohort study on vitamin D status and its impact during pregnancy and childhood in Indonesia

Introduction

The role of vitamin D in placental functions and fetal growth had been addressed in many reports with conflicting results. However, such report is limited for Indonesian population. The aim of this study was to explore the association between maternal vitamin D level in the first trimester and fetal biometry in the later stage of pregnancy with adjusted OR for other determinants like hemoglobin and ferritin level.

Methods

From July 2016 a prospective cohort study of pregnant women had begun in four cities in West Java, Indonesia. Data on maternal vitamin D, ferritin, hemoglobin level, maternal demography and fetal biometry were analyzed with linear regression.

Results

Among 203 recruited women, 195 (96.06%) had hypovitaminosis D. One hundred fifty two (75%) were in deficient state and 43 women (21%) were in insufficient state. Women with insufficient vitamin D had the highest proportion of anemia, while women with normal vitamin D level had the highest proportion of low ferritin level. Maternal serum vitamin D showed significant associations with biparietal diameter (β = 0.141, p = 0.042) and abdominal circumference (β = 0.819, p = 0.001) after adjustment with maternal age, pre-pregnancy body mass index, parity, serum ferritin level, and hemoglobin level.

Conclusion

Our study suggested that sufficient maternal vitamin D level was an important factor to improve fetal growth and development.

High Pregnancy, Cord Blood, and Infant Vitamin D Concentrations May Predict Slower Infant Growth

CONTEXT

The relationship of maternal and infant 25-hydroxyvitamin D concentration [25(OH)D] with infant growth is unclear.

OBJECTIVE

Our objective was to explore whether 25(OH)D in pregnancy, umbilical cord blood (UCB), or in infancy was associated with infant growth.

DESIGN

This study involved 798 healthy infants and their mothers in Finland. We assessed 25(OH)D during pregnancy, from UCB at birth, and from the infant at the age of 12 months.

MAIN OUTCOME MEASURES

Infant length, weight, length-adjusted weight, and head circumference at 6 and 12 months and midupper-arm circumference at 12 months.

RESULTS

Of the mothers and infants, 96% and 99% were vitamin D sufficient [25(OH)D ≥50 nmol/L], respectively. Mothers with pregnancy 25(OH)D >125 nmol/L had the shortest, lightest (in weight), and thinnest (in length-adjusted weight) infants at 6 months (P for all < 0.05). For each 10 nmol/L higher UCB 25(OH)D, the infants were 0.03 SD score (SDS) shorter at 6 months (95% CI -0.05 to -0.01), adjusted for birth size, infant 25(OH)D, and parental height. Higher UCB 25(OH)D associated with smaller head circumference at 6 and 12 months (P for all <0.05) but attenuated after adjustments. Mothers with pregnancy 25(OH)D >125 nmol/L had the thinnest infants at 12 months (P = 0.021). For each 10 nmol/L higher infant 25(OH)D, the infants were 0.03 SDS lighter (-0.05 to -0.01) and 0.03 SDS thinner (-0.05 to 0.00) at 12 months.

CONCLUSIONS

Our results suggest that high pregnancy, cord blood, and infant vitamin D concentration may have disadvantageous effects on infant growth.

Vitamin D status during pregnancy and offspring outcomes: a systematic review and meta-analysis of observational studies

BACKGROUND/OBJECTIVES

Vitamin D deficiency during pregnancy may influence adverse outcomes in offspring. The aim of this systematic review and meta-analysis of observational studies was to assess the association between low prenatal concentrations of 25(OH)D (by using three different cut-off levels), preterm birth (PTB) and anthropometric and neurodevelopmental outcomes in offspring.

SUBJECTS/METHODS

Studies reporting data on the association between maternal vitamin D concentrations and offspring outcomes identified through a systematic review of scientific literature published in PubMed/MEDLINE, Scopus and the Cochrane Library databases up to April 2017.

RESULTS

We included 54 eligible studies. Vitamin D-deficient mothers (<30 nmol/L) had offspring with lower birthweight (MD -87.82 g; 95% CI -119.73, -55.91 g), head circumference (MD -0.19 cm; 95% CI -0.32, -0.06 cm) and a higher risk of small for gestational age (SGA) infants and PTB (OR 1.59; 95% CI 1.24, 2.03) compared to mothers with concentrations ≥30 nmol/L. Vitamin D insufficiency (<50 nmol/L) was associated with a higher risk of SGA and PTB (OR 1.43; 95% CI 1.08, 1.91 and OR 1.28; 95% CI 1.08, 1.52, respectively). Concentrations of 25(OH)D ≥75 nmol/L were not found to be associated with birthweight, SGA or PTB. Offspring of vitamin D-insufficient mothers had lower scores in mental (MD -1.12 points; 95% CI -1.82, -0.42 cm) and language developmental tests (MD -0.35 points; 95% CI -1.00, 0.31 cm).

CONCLUSION

Maternal vitamin D deficiency is associated with offspring adverse anthropometric outcomes and PTB; insufficiency with a higher risk of SGA, PTB and adverse neurodevelopmental outcomes.

Maternal Vitamin D Deficiency and the Risk of Small for Gestational Age: A Meta-analysis

BACKGROUND

Inconsistencies among studies still exist in regard to the associations between maternal vitamin D deficiency and the risk of small for gestational age.

METHODS

We conducted a meta-analysis of observational studies to evaluate these associations. We searched electronic databases for literature published in PubMed, Medline, Web of Science, Embase and the Cochrane Library up to Dec 2016 using the following keywords: "vitamin D" or "cholecalciferol" or "25-OHD" or "25-hydroxyvitamin D" in combination with "small for gestational age" or "SGA" or "fetal outcome" or "pregnancy outcome".

RESULTS

Twelve studies involving 19,027 participants were included in this meta-analysis. Pregnant women with vitamin D deficiency (25-OHD levels<50 nmol/L) experienced an increased risk of SGA (odds ratio (OR) =1.41, 95% confidence interval (CI): 1.14, 1.75). The vitamin D concentration of the SGA group was lower than that of the non-SGA group (mean difference: -1.75 nmol/L, 95%CI: -3.23, -0.27).

CONCLUSION

Maternal vitamin D deficiency during pregnancy may be associated with an increased risk of SGA.

Longitudinal Maternal Vitamin D Status during Pregnancy Is Associated with Neonatal Anthropometric Measures

Findings on maternal 25-hydroxyvitamin D (25[OH]D) and neonatal anthropometry are inconsistent, and may at least be partly due to variations in gestational week (GW) of 25(OH)D measurement and the lack of longitudinal 25(OH)D measurements across gestation. The aim of the current study was to examine the associations of longitudinal measures of maternal 25(OH)D and neonatal anthropometry at birth. This study included 321 mother–offspring pairs enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies–Singletons. This study was a prospective cohort design without supplementation and without data on dietary supplementation. Nevertheless, measurement of plasma 25(OH)D reflects vitamin D from different sources, including supplementation. Maternal concentrations of total 25(OH)D were measured at 10–14, 15–26, 23–31, and 33–39 GW and categorized as <50 nmol/L, 50–75 nmol/L, and >75 nmol/L. Generalized linear models were used to examine associations of 25(OH)D at each time-point with neonate birthweight z-score, length, and sum of skinfolds at birth. At 10–14 GW, 16.8% and 49.2% of women had 25(OH)D <50 nmol/L and between 50–75 nmol/L, respectively. The association of maternal 25(OH)D with neonatal anthropometry differed by GW and women’s prepregnancy BMI (normal (<25.0 kg/m²), overweight/obese (25.0–44.9 kg/m²)). All analyses were stratified by prepregnancy BMI status. Among women with an overweight/obese BMI, 25(OH)D <50 nmol/L at 10–14 GW was associated with lower birthweight z-score (0.56; 95% CI: −0.99, −0.13) and length (−1.56 cm; 95% CI: −3.07, −0.06), and at 23–31 GW was associated with shorter length (−2.77 cm; 95% CI: −13.38, −4.98) and lower sum of skinfolds (−9.18 mm; 95% CI: −13.38, −4.98). Among women with a normal BMI, 25(OH)D <50 nmol/L at 10–14 GW was associated with lower sum of skinfolds (−2.64 mm; 95% CI: −5.03, −0.24), at 23–31 GW was associated with larger birthweight z-scores (0.64; 95% CI: 0.03, 1.25), and at 33-39 GW with both higher birthweight z-score (1.22; 95% CI: 0.71, 1.73) and longer length (1.94 cm; 95% CI: 0.37, 3.52). Maternal 25(OH)D status during pregnancy was associated with neonatal anthropometric measures, and the associations were specific to GW of 25(OH)D measurement and prepregnancy BMI.

Cord serum 25-hydroxyvitamin D is not associated with cranial anthropometrics in infants up to 6 months of age. An Odense Child Cohort study

Skull changes are poorly described in vitamin D insufficiency [serum 25-hydroxyvitamin D (s-25(OH)D) 25-50 nmol/L]. We aimed to investigate factors associated with cranial anthropometrics in infants, especially s-25(OH)D. In infants 2.5-6 months old from the Odense Child Cohort, associations between cord and pregnancy s-25(OH)D and anterior fontanel area (n = 765), head circumference (HC, n = 1776) and head shape (n = 1527) were investigated along with other factors. Age was corrected for preterm birth. The mean (SD) s-25(OH)D in early pregnancy was 65.97 (21.33) nmol/L; late pregnancy 78.61 (27.18) nmol/L; and cord 47.1 (21.7) nmol/L. At median (IQR) age 3.7 (2.5-5.9) months, the fontanel area was 225 (0-1690) mm², and mean (SD) HC was 41.5 (1.5) cm. Asymmetric/flat head shape was present in 846 infants (55.3%). No associations were found between cord, early or late pregnancy s-25(OH)D and any cranial measure by univariate or adjusted analysis. Among significant, independent associations in multivariate analysis, fontanel area was associated inversely with gestational age (GA); HC was associated directly with GA, maternal pre-pregnancy overweight and caesarean section and inversely with smoking; and asymmetrical head shape showed a novel association with male sex: adjusted OR = 1.54 (95% CI 1.25; 1.89), p < 0.001. Other associations with asymmetrical head shape included parity 3+, gestational age and maternal age 30+ years (all protective). In conclusion, neither pregnancy nor cord s-25(OH)D was associated with fontanel size, HC or asymmetrical head shape despite a high prevalence of cord s-25(OH)D < 50 nmol/L. Lower GA was associated with larger fontanel size, lower HC and asymmetrical head shape, and boys more frequently had asymmetrical head shape, probably due to heavier heads.

A novel inverse association between cord 25-hydroxyvitamin D and leg length in boys up to three years. An Odense Child Cohort study

Background and aim

Long standing vitamin D deficiency in children causes rickets with growth impairment. We investigated whether sub-ischial leg length (SLL) is shorter, and cephalo-caudal length:length (CCL:L) ratio and sitting height:height (SH:H) ratio larger, with lower cord s-25-hydroxyvitamin D (25OHD) in the population-based prospective Odense Child Cohort, Denmark.

Methods

We included healthy singletons born to term with available measures of cord 25OHD and anthropometrics up to three years’ age. Linear regression was stratified by sex a priori and adjusted for maternal ethnicity, pre-pregnancy body mass index and smoking during pregnancy, season of blood sampling and child age.

Results

Median (IQR) cord 25OHD was 48.0 (34.0–62.4) nmol/L. At mean age 19.1 months, n = 504, mean (SD) SLL was 31.7 (1.7) cm; CCL:L-ratio 0.62 (0.01). At 36.3 months, n = 956, mean SLL was 42.9 (2.0) cm; SH:H-ratio 0.56 (0.01). No participants had rickets. In adjusted analyses, 19-months-old boys had 0.1 cm shorter SLL (p = 0.009) and 0.1% higher CCL:L-ratio (p = 0.04) with every 10 nmol/L increase in cord 25OHD. Similar findings were seen for late pregnancy 25OHD. In the highest cord 25OHD quartile (>60.7 nmol/L), SLL was 0.8 cm shorter (95% C.I.: 1.36;-0.29, linear trend, p = 0.004), and CCL:L-ratio 0.8% higher (95% C.I. 8.0x10^-05;0.01, linear trend, p = 0.01), compared to lowest quartile (<30.7 nmol/L). Similar associations with cord 25OHD were observed in 3-year-old boys. No consistent associations between 25OHD and anthropometrics were seen in girls at either age.

Conclusion

No leg shortening was found with decreasing cord s-25OHD in a healthy population of infants. A small, yet significant inverse association between cord 25OHD and SLL in boys 1½-3 years warrants further investigations.

Impact of vitamin D on pregnancy-related disorders and on offspring outcome

Observational studies from all over the world continue to find high prevalence rates of vitamin D insufficiency and deficiency in many populations, including pregnant women. Beyond its classical function as a regulator of calcium and phosphate metabolism, vitamin D elicits numerous effects in the human body. Current evidence highlights a vital role of vitamin D in mammalian gestation. During pregnancy, adaptations in maternal vitamin D metabolism lead to a physiologic increase of vitamin D levels, mainly because of an increased renal production, although other potential sources like the placenta are being discussed. A sufficient supply of mother and child with calcium and vitamin D during pregnancy ensures a healthy bone development of the fetus, whereas lack of either of these nutrients can lead to the development of rickets in the child. Moreover, vitamin D insufficiency during pregnancy has consistently been associated with adverse maternal and neonatal pregnancy outcomes. In multitudinous studies, low maternal vitamin D status was associated with a higher risk for preeclampsia, gestational diabetes mellitus and other gestational diseases. Likewise, several negative consequences for the fetus have been reported, including fetal growth restriction, increased risk of preterm birth and a changed susceptibility for later-life diseases. However, study results are diverging and causality has not been proven so far. Meta-analyses on the relationship between maternal vitamin D status and pregnancy outcomes revealed a wide heterogeneity of studied populations and the applied methodology in vitamin D assessment. Until today, clinical guidelines for supplementation cannot be based on high-quality evidence and it is not clear if the required intake for pregnant women differs from non-pregnant women. Long-term safety data of vitamin D supplementation in pregnant women has not been established and overdosing of vitamin D might have unfavorable effects, especially in mothers and newborns with mutations of genes involved in vitamin D metabolism. Reliable data from large observational and interventional randomized control trials are urgently needed as a basis for any detailed and safe recommendations for supplementation in the general population and, most importantly, in pregnant women. This is of utmost importance, as ensuring a sufficient vitamin D-supply of mother and child implies a great potential for the prevention of birth complications and development of diseases.

Association between maternal mid-gestation vitamin D status and neonatal abdominal adiposity

Objectives

Lower vitamin D status has been associated with adiposity in children through adults. However, the evidence of the impact of maternal vitamin-D status during pregnancy on offspring’s adiposity is mixed. The objective of this study was to examine the associations between maternal vitamin-D [25(OH)D] status at mid-gestation and neonatal abdominal adipose tissue (AAT) compartments, particularly the deep subcutaneous adipose tissue linked with metabolic risk.

Methods

Participants (N = 292) were Asian mother-neonate pairs from the mother-offspring cohort, Growing Up in Singapore Towards healthy Outcomes. Neonates born at ≥34 weeks gestation with birth weight ≥2000 g had magnetic resonance imaging (MRI) within 2-weeks post-delivery. Maternal plasma glucose using an oral glucose tolerance test and 25(OH)D concentrations were measured. 25(OH)D status was categorized into inadequate (≤75.0 nmol/L) and sufficient (>75.0 nmol/L) groups. Neonatal AAT was classified into superficial (sSAT), deep subcutaneous (dSAT), and internal (IAT) adipose tissue compartments.

Results

Inverse linear correlations were observed between maternal 25(OH)D and both sSAT (r = −0.190, P = 0.001) and dSAT (r = −0.206, P < 0.001). Each 1 nmol/L increase in 25(OH)D was significantly associated with reductions in sSAT (β = −0.14 (95% CI: −0.24, −0.04) ml, P = 0.006) and dSAT (β = −0.04 (−0.06, −0.01) ml, P = 0.006). Compared to neonates of mothers with 25(OH)D sufficiency, neonates with maternal 25(OH)D inadequacy had higher sSAT (7.3 (2.1, 12.4) ml, P = 0.006), and dSAT (2.0 (0.6, 3.4) ml, P = 0.005) volumes, despite similar birth weight. In the subset of mothers without gestational diabetes, neonatal dSAT was also greater (1.7 (0.3, 3.1) ml, P = 0.019) in neonates with maternal 25(OH)-inadequacy. The associations with sSAT and dSAT persisted even after accounting for maternal glycemia (fasting and 2-h plasma glucose).

Conclusions

Neonates of Asian mothers with mid-gestation 25(OH)D inadequacy have a higher abdominal subcutaneous adipose tissue volume, especially dSAT (which is metabolically similar to visceral adipose tissue in adults), even after accounting for maternal glucose levels in pregnancy.

Effect of vitamin D3 supplementation in pregnancy on risk of pre-eclampsia - Randomized controlled trial

BACKGROUND

Vitamin D plays pivotal role in decidualization and implantation of the placenta. Recent researches have shown that low level of vitamin D3 "25-hydroxyvitamin D (25[OH]D)" in serum is a risk factor for pre-eclampsia. Latest evidence supports role of vitamin D3 deficiency treatment in reducing the risk of pre-eclampsia. The aim of this study is to determine the effect of antenatal supplementation of vitamin D3 on the risk of pre-eclampsia and to explore the dose effect in attaining the vitamin D3 normal level.

METHOD

An open labelled randomized controlled study was conducted on 179 pregnant women presenting in King Fahad Medical City antenatal clinic from Oct 2012-Oct 2015. Patients with age less than 20 years or more than 40 years, pregnancy with fetal anomalies, history of hypertension, pre-eclampsia, recurrent miscarriage, chronic renal or hepatic disease and malignancy were excluded from the study. Serum 25[OH]D was analysed during the first trimester (between 6 and 12 weeks of pregnancy). Patients with vitamin D3 deficiency (serum levels <25 nmol/L) were included in the study and randomized for vitamin D3 supplementation 400 IU (Group 1) versus 4000 IU (Group 2). Both groups were compared for the prevalence of pre-eclampsia and dose effect on vitamin D level.

RESULTS

Of 179 gravidae enrolled, 164 completed the trial. Mean maternal 25[OH]D was significantly increased in group 2 from 16.3 ± 5 nmol/mL to 72.3 ± 30.9 nmol/mL compared with group 1 from 17.5 ± 6.7 nmol/mL to 35.3 ± 20.7 nmol/mL (p > 0.0001). The relative risk reduction (RRR) for attaining ≥75 nmol/L before delivery was significantly higher (RRR 93.2 [CI 79-98] when treated with 4000 IU. The total incidence of pre-eclampsia in the study population was 4.3%. In comparison to group 1, the group 2 reported fewer pre-eclampsia events during the study period (8.6% versus 1.2%; p < 0.05). The total number of IUGRs was lesser in the group 2 (9.6%) versus group 1 (22.2%); p = 0.027. However, other obstetric outcomes were comparable between both groups.

CONCLUSION

Vitamin D supplementation in the deficient group reduces the risk of pre-eclampsia and IUGR in a dose dependant manner. However larger clinical trials are essential to investigate optimum dosage of vitamin D3 in this group.

Prenatal vitamin D status and offspring's growth, adiposity and metabolic health: a systematic review and meta-analysis

In this systematic review and meta-analysis of observational studies, we aimed to estimate the associations between prenatal vitamin D status and offspring growth, adiposity and metabolic health. We searched the literature in human studies on prenatal vitamin D status and offspring growth in PubMed, up to July 2017. Studies were selected according to their methodological quality and outcomes of interest (anthropometry, fat mass and diabetes in offspring). The inverse variance method was used to calculate the pooled mean difference (MD) with 95 % CI for continuous outcomes, and the Mantel-Haenszel method was used to calculate the pooled OR with 95 % CI for dichotomous outcomes. In all, thirty observational studies involving 35 032 mother-offspring pairs were included. Vitamin D status was evaluated by circulating 25-hydroxyvitamin D (25(OH)D) level. Low vitamin D status was based on each study's cut-off for low 25(OH)D levels. Low prenatal vitamin D levels were associated with lower birth weight (g) (MD -100·69; 95 % CI -162·25, -39·13), increased risk of small-for-gestational-age (OR 1·55; 95 % CI 1·16, 2·07) and an elevated weight (g) in infant at the age of 9 months (g) (MD 119·75; 95 % CI 32·97, 206·52). No associations were observed between prenatal vitamin D status and other growth parameters at birth, age 1 year, 4-6 years or 9 years, nor with diabetes type 1. Prenatal vitamin D may play a role in infant adiposity and accelerated postnatal growth. The effects of prenatal vitamin D on long-term metabolic health outcomes in children warrant future studies.

Maternal early pregnancy vitamin D status in relation to low birth weight and small-for-gestational-age offspring

Maternal vitamin D deficiency is an independent risk factor for fetal growth. We examined the associations between maternal vitamin D status (defined by 25-hydroxyvitamin D [25(OH)D]) at the first prenatal visit and measures of newborn and placental weight, in a large China cohort of singleton, term, live births. From July 2015 to June 2016, women delivering singleton, term, live births with 25(OH)D measured at a first prenatal visit (N=747). Birth weight, placental weight, the placental to fetal weight ratio, and small for gestational age (SGA) were measured. The relationship between levels of 25(OH)D and SGA were evaluated using univariate and multivariate regression analysis. Vitamin D deficiency was defined as 25(OH)D less than 20ng/ml. In those women, 76.9% (95%CI: 74%-78%) were defined as vitamin D deficiency. Incidence of SGA was also high (13.3%; 95%CI: 10.8%-15.7%). We found a nonlinear relation between 25(OH)D and birth weight as well as head circumference (P<0.01). Birth weight and head circumference increased by 69 [95%CI: 38-122] g and 0.31 (0.22-0.40) cm, respectively, per 1ng/ml increase in maternal 25(OH)D up to 20ng/ml and then leveled off thereafter. The SGA distribution across the 25(OH)D quartiles ranged between 3.7% (fourth quartile) to 24.1% (first quartile). For each 1 unit decrease of plasma concentration of 25(OH)D, the unadjusted and adjusted risk of SGA increased by 19% (odds ratio 1.19 [95% CI 1.13-1.25], P<0.001) and 9% (1.08 [1.03-1.16], P=0.009), respectively. In a multivariate model using the vitamin D deficiency vs. other together with the clinical variables, the adjusted risk of SGA increased by 205% (odds ratio 3.05 [95% CI 2.24-4.40], P=0.001). Maternal vitamin D insufficiency is common during pregnancy and is independently associated with low birth weight and high risk of SGA in term infants.

Time Course of Vitamin D Depletion and Repletion in Reproductive-age Female C57BL/6 Mice

The use of animal models in vitamin D deficiency (VDD) research, particularly in regard to maternal deficits, has increased dramatically, yet these studies may be confounded due to ill-conceived experimental timelines. We conducted 2 experiments to (1) characterize the time course of VDD induction and repletion and (2) explore the long-term consequences of VDD on calcium homeostasis and body composition in reproductive-age female mice. Eight-week-old female C57BL/6 mice were randomized to receive either a vitamin D sufficient (VDS) or VDD diet; serum was collected weekly. At week 4, VDD mice were switched to VDS diet, and serum was collected weekly until week 8. Another group of same-age female mice was maintained on VDD diet for 40 wk. Body weights and serum were collected every 2 wk until week 40, when body composition was measured by using echoMRI. Mice did not become VDD until week 3 of the VDD diet and, after decreasing slightly at 4 wk, serum 25-hydroxyvitamin D remained unchanged through 40 wk. Vitamin D repletion to 25-hydroxyvitamin D concentrations considered adequate by the Institute of Medicine took 2 to 3 wk. Prolonged VDD in mice was marked by hypocalcemia and hyperparathyroidism and led to proportional decreases in both lean and fat mass. These data provide guidance in the design of studies using mice as a maternal VDD model, especially those exploring its effects on the developmental origins of health and disease and highlight the importance of monitoring and controlling the calciotropic effects of diet-induced VDD. This study also shows that prolonged VDD in reproductive-age female C57BL/6 mice induces metabolically meaningful changes in absolute, but not relative, body composition.

Maternal Vitamin D Status and the Relationship with Neonatal Anthropometric and Childhood Neurodevelopmental Outcomes: Results from the Seychelles Child Development Nutrition Study

Vitamin D has an important role in early life; however, the optimal vitamin D status during pregnancy is currently unclear. There have been recent calls for pregnant women to maintain circulating 25-hydroxyvitamin D (25(OH)D) concentrations >100 nmol/L for health, yet little is known about the long-term potential benefits or safety of achieving such high maternal 25(OH)D concentrations for infant or child health outcomes. We examined maternal vitamin D status and its associations with infant anthropometric and later childhood neurocognitive outcomes in a mother-child cohort in a sun-rich country near the equator (4.6° S). This study was conducted in pregnant mothers originally recruited to the Seychelles Child Development Nutrition Study. Blood samples (n = 202) taken at delivery were analysed for serum 25-hydroxyvitamin D (25(OH)D) concentrations. Multiple linear regression models assessed associations between maternal 25(OH)D and birth weight, infant head circumference, and neurocognitive outcomes in the children at age 5 years. Mothers were, on average, 27 years of age, and the children’s average gestational age was 39 weeks. None of the women reported any intake of vitamin D supplements. Maternal 25(OH)D concentrations had a mean of 101 (range 34–218 nmol/L) and none were deficient (<30 nmol/L). Maternal 25(OH)D concentrations were not associated with child anthropometric or neurodevelopmental outcomes. These findings appear to indicate that a higher vitamin D status is not a limiting factor for neonatal growth or neurocognitive development in the first 5 years of life. Larger studies with greater variability in vitamin D status are needed to further explore optimal cut-offs or non-linear associations (including for maternal health) that might exist among populations with sub-optimal exposure.

Association between maternal vitamin D deficiency and small for gestational age: evidence from a meta-analysis of prospective cohort studies

OBJECTIVE

To determine whether maternal vitamin D deficiency during pregnancy is associated with small for gestational age (SGA).

METHODS

A comprehensive literature search of PubMed, the Cochrane Library, Embase, and the Elsevier ScienceDirect library was conducted to identify relevant articles reporting prospective cohort studies in English, with the last report included published in February 2017. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to evaluate the correlation in a random effects model.

RESULTS

A total of 13 cohort studies were included in this meta-analysis with a sample of 28 285 individuals from seven countries. The pooled overall OR for babies born SGA was 1.588 (95% CI 1.138 to 2.216; p<0.01) for women with vitamin D deficiency. The prevalence of vitamin D deficiency during pregnancy varied from 13.2% to 77.3%. Subgroup analyses identified no significant differences in the association between vitamin D deficiency and SGA based on study quality, gestational week during which blood sampling was performed, cut-off vitamin D levels, sample size, adjustment for critical confounders and method for measuring vitamin D.

CONCLUSION

This meta-analysis suggests that vitamin D deficiency is associated with an increased risk of SGA.

Modifiable risk factors in the first 1000 days for subsequent risk of childhood overweight in an Asian cohort: significance of parental overweight status

BACKGROUND/OBJECTIVE

Many studies have identified early-life risk factors for subsequent childhood overweight/obesity, but few have evaluated how they combine to influence risk of childhood overweight/obesity. We examined associations, individually and in combination, of potentially modifiable risk factors in the first 1000 days after conception with childhood adiposity and risk of overweight/obesity in an Asian cohort.

METHODS

Six risk factors were examined: maternal pre-pregnancy overweight/obesity (body mass index (BMI) ⩾25 kg m^-2), paternal overweight/obesity at 24 months post delivery, maternal excessive gestational weight gain, raised maternal fasting glucose during pregnancy (⩾5.1 mmol l^-1), breastfeeding duration <4 months and early introduction of solid foods (<4 months). Associations between number of risk factors and adiposity measures (BMI, waist-to-height ratio (WHtR), sum of skinfolds (SSFs), fat mass index (FMI) and overweight/obesity) at 48 months were assessed using multivariable regression models.

RESULTS

Of 858 children followed up at 48 months, 172 (19%) had none, 274 (32%) had 1, 244 (29%) had 2, 126 (15%) had 3 and 42 (5%) had ⩾4 risk factors. Adjusting for confounders, significant graded positive associations were observed between number of risk factors and adiposity outcomes at 48 months. Compared with children with no risk factors, those with four or more risk factors had s.d. unit increases of 0.78 (95% confidence interval 0.41-1.15) for BMI, 0.79 (0.41-1.16) for WHtR, 0.46 (0.06-0.83) for SSF and 0.67 (0.07-1.27) for FMI. The adjusted relative risk of overweight/obesity in children with four or more risk factors was 11.1(2.5-49.1) compared with children with no risk factors. Children exposed to maternal pre-pregnancy (11.8(9.8-13.8)%) or paternal overweight status (10.6(9.6-11.6)%) had the largest individual predicted probability of child overweight/obesity.

CONCLUSIONS

Early-life risk factors added cumulatively to increase childhood adiposity and risk of overweight/obesity. Early-life and preconception intervention programmes may be more effective in preventing overweight/obesity if they concurrently address these multiple modifiable risk factors.

Prenatal Vitamin D Intake, Cord Blood 25-Hydroxyvitamin D, and Offspring Body Composition: The Healthy Start Study

Vitamin D deficiency in pregnancy may be associated with increased offspring adiposity, but evidence from human studies is inconclusive. We examined associations between prenatal vitamin D intake, 25-hydroxyvitamin D (25(OH)D) in cord blood, and offspring size and body composition at birth and 5 months. Participants included 605 mother-offspring dyads from the Healthy Start study, an ongoing, pre-birth prospective cohort study in Denver, Colorado, USA. Prenatal vitamin D intake was assessed with diet recalls and questionnaires, and offspring body composition was measured via air displacement plethysmography at birth and 5 months. General linear univariate models were used for analysis, adjusting for maternal age, race/ethnicity, pre-pregnancy body mass index (BMI), offspring sex, and gestational age at birth. Non-Hispanic white race, lower pre-pregnancy BMI, higher prenatal vitamin D intake, and summer births were associated with higher cord blood 25(OH)D. Higher 25(OH)D was associated with lower birthweight (β = -6.22, p = 0.02), but as maternal BMI increased, this association became increasingly positive in direction and magnitude (β = 1.05, p = 0.04). Higher 25(OH)D was also associated with lower neonatal adiposity (β = -0.02, p < 0.05) but not after adjustment for maternal BMI (β = -0.01, p = 0.25). Cord blood 25(OH)D was not associated with offspring size or body composition at 5 months. Our data confirm the hypothesis that vitamin D exposure in early life is associated with neonatal body size and composition. Future research is needed to understand the implications of these associations as infants grow.

Vitamin D and risk of preterm birth: Up-to-date meta-analysis of randomized controlled trials and observational studies

AIM

We performed a meta-analysis of randomized controlled trials (RCT) and observational studies to answer the two following questions: (i) whether low maternal circulating 25 hydroxyvitamin D (25-OHD) is associated with an increased risk of preterm birth (PTB) or spontaneous PTB (sPTB); and (ii) whether vitamin D supplementation alone during pregnancy can reduce the risk of PTB.

METHODS

Literature search was carried out using Pubmed, Web of Science and Embase databases up to June 2016. Pooled OR or relative risk (RR) with 95%CI were computed using fixed or random effects models depending on the size of heterogeneity. Subgroup analysis was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Egger's test and Begg's test.

RESULTS

Twenty-four articles (six RCT and 18 observational studies) were identified. Maternal circulating 25-OHD deficiency (pooled OR, 1.25; 95%CI: 1.13-1.38) rather than insufficiency (pooled OR, 1.09; 95%CI: 0.89-1.35) was associated with an increased risk of PTB, and vitamin D supplementation alone during pregnancy could reduce the risk of PTB (pooled RR, 0.57; 95%CI: 0.36-0.91). This was also the case for the sPTB subgroup (circulating 25-OHD <50 vs >50 nmol/L; pooled OR, 1.45; 95%CI: 1.20-1.75).

CONCLUSIONS

Maternal circulating 25-OHD deficiency could increase PTB risk and vitamin D supplementation alone during pregnancy could reduce PTB risk. Extrapolation of the results, however, must be done with caution, and there is urgent need for larger, better-designed RCT to confirm this effect.

Vitamin D levels during pregnancy and associations with birth weight and body composition of the newborn: a longitudinal multiethnic population-based study

We investigated associations between serum 25-hydroxyvitamin D (25(OH)D) in pregnancy and birth weight and other neonatal anthropometric measures. The present study was a population-based, multiethnic cohort study of 719 pregnant women (59 % ethnic minorities) in Oslo, Norway, delivering a singleton neonate at term and with birth weight measurements. In a representative sample, anthropometric measurements were taken. Maternal 25(OH)D was measured at gestational weeks 15 and 28. Women with 25(OH)D <37 nmol/l were recommended vitamin D3 supplementation. Separate linear regression analyses were performed to model the associations between 25(OH)D and each of the outcomes: birth weight, crown-heel length, head circumference, abdominal circumference, sum of skinfolds, mid-upper arm circumference and ponderal index. In early pregnancy, 51 % of the women were vitamin D deficient (25(OH)D<50 nmol/l). In univariate analyses and in models adjusting for maternal age, parity, education, prepregnancy BMI, season, gestational age and neonate sex, maternal 25(OH)D was significantly associated with birth weight, head circumference, abdominal circumference and ponderal index (P<0·05 for all), when used as a continuous variable and categorised (consistently low, consistently high, increasing and decreasing level). However, after adjusting for ethnicity, 25(OH)D was no longer associated with any of the outcomes. Sex-specific associations for abdominal circumference and sum of skinfolds were found (P for interaction<0·05). In conclusion, in a multiethnic cohort of pregnant women with high prevalence of vitamin D deficiency, we found no independent relation between maternal vitamin D levels and any of the neonatal anthropometric measures, and the strong association between ethnicity and neonatal outcomes was not affected by maternal vitamin D status.