Vitamin D intake during pregnancy: association with maternal characteristics and infant birth weight

Income effect of prenatal sunlight exposure: Empirical evidence from China

Despite a growing interest in the impacts of prenatal factors on adulthood quality of life, economists have not estimated the income effects of sunlight exposures by mothers during pregnancy. This paper estimates such effects using data from China General Social Survey and China National Meteorological Data Service Center. The results show that the income effects of prenatal sunlight exposure in the second trimester are significantly positive. The effects differ for individuals born in different months and the effects are larger for female employees, older employees, those born in rural areas, in the pre-reform period, or whose mothers are less-educated. Finally, we investigate the possible mechanisms via the human capital pathway, discovering that fetuses with longer sunlight exposure in the second trimester are healthier and do more exercises in adulthood. It is suggested that families, communities, policymakers should pay attention to prenatal sunlight exposure, especially for pregnant women in the developing world who are less educated or live in rural areas.

The Camden Study-A Pregnancy Cohort Study of Pregnancy Complications and Birth Outcomes in Camden, New Jersey, USA

BACKGROUND

Pregnancy is a unique stage of the life course characterized by trade-offs between the nutritional, immune, and metabolic needs of the mother and fetus. The Camden Study was originally initiated to examine nutritional status, growth, and birth outcomes in adolescent pregnancies and expanded to study dietary and molecular predictors of pregnancy complications and birth outcomes in young women.

METHODS

From 1985-2006, 4765 pregnant participants aged 12 years and older were recruited from Camden, NJ, one of the poorest cities in the US. The cohort reflects a population under-represented in perinatal cohort studies (45% Hispanic, 38% non-Hispanic Black, 17% White participants; 98% using Medicaid in pregnancy). Study visits, including questionnaires, dietary assessments, and biospecimen collection, occurred in early and late pregnancy as well as at delivery. Medical records were abstracted, and a subset of mothers and infants participated in a six-week postpartum visit.

RESULTS

Findings from the Camden Study have added to the understanding of adolescent and young adult maternal health and perinatal outcomes. These include associations of adolescent linear growth while pregnant with smaller neonatal birth size, low dietary zinc intake in early pregnancy with increased risk of delivery <33 gestational weeks, and higher circulating fatty acid levels with greater insulin resistance. More recent analyses have begun to unpack the biochemical pathways in pregnancy that may be shaped by race as an indicator of systemic racism.

CONCLUSIONS

The Camden Study data and biorepositories are well-positioned to support future research aimed at better understanding perinatal health in under-represented women and infants. Linkages to subsequent health and administrative records and the potential for recontacting participants over 18-39 years after initial participation may provide key insights into the trajectories of maternal and child health across the life course.

Cohort profile: The Camden Study - a pregnancy cohort study of pregnancy complications and birth outcomes in Camden, New Jersey, USA

Background

Pregnancy is a unique stage of the life course characterized by trade-offs between the nutritional, immune, and metabolic needs of the mother and fetus. The Camden Study was originally initiated to examine nutritional status, growth, and birth outcomes in adolescent pregnancies and expanded to study dietary and molecular predictors of pregnancy complications and birth outcomes in young women.

Methods

From 1985-2006, 4765 pregnant participants aged 12 years and older were recruited from Camden, NJ, one of the poorest cities in the U.S. The cohort reflects a population under-represented in perinatal cohort studies (45% Hispanic, 38% non-Hispanic Black, 17% White participants; 98% using Medicaid in pregnancy). Study visits, including questionnaires, dietary assessments, and biospecimen collection, occurred in early and late pregnancy as well as at delivery. Medical records were abstracted, and a subset of mothers and infants participated in a six-week postpartum visit.

Results

Over the last five decades, the Camden Study has provided data toward the publication of numerous peer-reviewed papers. Results show that adolescent linear growth in pregnancy is associated with smaller birth size, possibly due to impaired hemodynamics. In the context of preterm birth and other perinatal outcomes, analyses of nutritional data have demonstrated the importance of micronutrients (e.g., folate, iron, zinc), as well as glucose/insulin dynamics and prenatal supplement use. More recent analyses have begun to unpack the biochemical pathways in pregnancy that may be shaped by race as an indicator for systemic racism.

Conclusions

The Camden Study data and biorepositories are well-positioned to support future research aimed at better understanding perinatal health in under-represented women and infants. Linkages to subsequent health and administrative records and the potential for recontacting participants over 18-39 years after initial participation may provide key insights into the trajectories of maternal and child health across the life course.

Association of vitamin D intake during pregnancy with small vulnerable newborns: a population-based cohort study

Maternal vitamin D deficiency is common worldwide and has a significant impact on newborns. However, whether vitamin D intake during pregnancy is related to small vulnerable newborns (SVN) has not been confirmed. Thus, we sought to examine the relationship between maternal vitamin D intake, including vitamin D supplementation and dietary intake, and the risk of SVN. A total of 2980 Chinese mother-infant pairs were included in this study. Information on vitamin D supplementation and dietary intake was prospectively collected through face-to-face interviews. The outcomes assessed included low birth weight (LBW), preterm birth (PTB), small for gestational age (SGA), and SVN (having LBW, PTB, or SGA). Logistic regression models were used to evaluate the association of vitamin D intake with different types of SVN, and a restricted cubic spline function was modeled to explore their dose-response associations. Compared to the lowest total vitamin D intake in the first trimester, the highest total vitamin D intake was associated with a 50.0% decrease in the SGA risk (OR: 0.50, 95% CI: 0.26, 0.96) and a 41.0% decrease in the SVN risk (OR: 0.59, 95% CI: 0.36, 0.95). Similar protective results were observed between vitamin D supplementation in the first trimester and SGA and SVN risks. Moreover, a significant L-shaped relationship was identified for total vitamin D intake, vitamin D supplementation, and dietary intake with the risk of different types of SVN. In conclusion, higher total vitamin D intake and supplementation in the first trimester were associated with a reduced risk of SGA and SVN.

Consequences of Maternal Vitamin D Deficiency on Newborn Health

BACKGROUND AND OBJECTIVES

Maternal-fetal gestational pathology is one of the biggest challenges in the field of health at this moment. The current study is designed to determine the effects of vitamin D on pregnancy, starting with the idea that impairment of vitamin D status is thought to be correlated with impairment of the newborn's health.

MATERIALS AND METHODS

In this retrospective study, we tried to establish the link between vitamin D deficiency and maternal characteristics and also how it impacted the clinical status of the newborn. We analyzed a group of 260 patients: 130 pregnant women and 130 newborns, in whom vitamin D status was detected using the serum levels of 25-hydroxyvitamin D (25-(OH)D).

RESULTS

The results showed that vitamin D deficiency has a high incidence among pregnant women, as was presented in many important international studies. Our study also showed a positive, direct correlation between the mother's and newborn's vitamin D status.

CONCLUSIONS

Taking into consideration that vitamin D deficiency has been correlated with many complications, both in maternal and newborn health, a serum level determination of 25-(OH)D is necessary in the first trimester of pregnancy, and after that, adequate supplementation is necessary in order to prevent any negative effects.

A Study of Vitamin D Status and Its Influencing Factors among Pregnant Women in Szeged, Hungary: A Secondary Outcome of a Case-Control Study

Adequate vitamin D (VD) intake during pregnancy is needed for fetal development and maternal health maintenance. However, while there is no doubt regarding its importance, there is not a unified recommendation regarding adequate intake. The main aim of our study was to measure the VD serum level of studied women, together with its potential influencing factors: demographic (i.e., age, level of education, relationship status and type of residence), conception and pregnancy related factors. Results are based on secondary data analyses of a retrospective case-control study of 100 preterm and 200 term pregnancies, where case and control groups were analyzed together. Data collection was based on a self-administered questionnaire, health documentation, and maternal serum VD laboratory tests. VD intake was evaluated by diet and dietary supplement consumption. According to our results, 68.1% of women took some kind of prenatal vitamin, and only 25.9% of them knew about its VD content. Only 12.1% of included women reached the optimal, 75 nmol/L serum VD level. Higher maternal serum levels were associated with early pregnancy care visits (p = 0.001), assisted reproductive therapy (p = 0.028) and advice from gynecologists (p = 0.049). A correlation was found between VD intake and serum levels (p < 0.001). Despite the compulsory pregnancy counselling in Hungary, health consciousness, VD intake and serum levels remain below the recommendations. The role of healthcare professionals is crucial during pregnancy regarding micronutrients intake and the appropriate supplementation dose.

Prevalence of vitamin D insufficiency in early pregnancies- a Singapore study

Vitamin D plays an essential role in bone and mineral metabolism. There is increased interest in understanding prevalence of Vitamin D deficiency in pregnancy as many studies report association of low vitamin D levels with obstetric complications and neonatal sequelae. There is a paucity of studies in Singapore evaluating levels of vitamin D levels during the first trimester of pregnancies. We aim to study the prevalence of vitamin D insufficiency in this population. Our study assessed vitamin D levels in these women. Vitamin D (Plasma 25(OH)D concentration) levels in multiracial women during the first trimester were collected via venepuncture at their booking antenatal visit. They were stratified into sufficient ≥30ng/ml, insufficient ≥20ng/ml and <30ng/ml, moderately deficient ≥10ng/ml and <20ng/ml and severely deficient <10ng/ml. 93 women were included in this study. Only 2.2% of our study population had sufficient vitamin D levels. In women who had insufficient levels, the heavier the weight, the more likely to be vitamin D deficient. Interestingly, we also note that the older the patient, the less likely they are to be deficient. In women with periconceptual multivitamin supplementation, the average vitamin D level for those with supplementation was 2.10ng/ml higher than those without. Majority of patients were recruited from a single study member's patient pool who were mostly Chinese. Prevalence of Vitamin D deficiency in general obstetric patients with higher BMI and darker skinned patients may be even lower in Singapore. The high prevalence of Vitamin D insufficiency in our patients prove that it is a prominent problem in our population. We aim to implement screening of vitamin D levels as part of antenatal investigations in the first trimester and recommend supplementation as required. We also hope to evaluate the association of low vitamin D levels with obstetric or neonatal complications further understanding its implications.

Maternal vitamin D intakes during pregnancy and child health outcome

We conducted a follow up of the children in Mongolia whose mothers received one of the three doses of vitamin D (600, 2000, or 4000 IU daily) during pregnancy as part of the randomized, double-blind, clinical trial of vitamin D supplementation to determine their impact on child health to two years. In the parental trial, 119 pregnant women were assigned to 600 IU/day, 121 were assigned 2000 IU/day, and 120 were assigned 4000 IU/day starting at 12-16 weeks' gestation and continuing throughout pregnancy. At baseline, maternal serum 25(OH)D concentrations were similar across arms; 91 % were 50 nmol/l. As expected, there was a dose-response association between the amount of vitamin D consumed (600, 2000, or 4000 IU daily) and maternal 25(OH)D levels at the end of the intervention. Total 311 children of 311 mothers were followed for 2 years to evaluate health outcomes. We determined the child's health outcomes (rickets, respiratory disease [pneumonia, asthma], and diarrhea/vomiting) using a questionnaire and physical examination (3, 6, and 24 months of age). Low levels of mothers' serum 25(OH)D during pregnancy increased the risk of developing rickets, respiratory illness, and other diseases in children during the early childhood period. Rickets was diagnosed in 15.6 % of children of women who received 600 IU of vitamin D during pregnancy, which was higher than in other vitamin D groups. Children in the group whose mothers received low doses of vitamin D (600 IU/day) had a greater probability of developing respiratory diseases compared to the other groups: pneumonia was diagnosed in n = 36 (35.0 %) which was significantly higher than the group receiving vitamin D 4000 IU/day (n = 34 (31.5 %) p = 0.048). In the group whose pregnant mother consumed 600 IU/day of vitamin D, the risk of child pneumonia was ∼ 2 times higher than in the group who consumed 4000 IU/day (OR=1.99, 95 % CI: 1.01-3.90). The incidence of diarrhea and vomiting in children was 12.1 % lower in the 2000 IU/day group and 13.1 % lower in the 4000 IU/day group compared with the 600 IU/day group (p = 0.051). The offspring of pregnant women who regularly used vitamin D at doses above 600 IU/day had lower respiratory disease, rickets, and diarrheal risks at 2 years.

Mode of delivery and maternal vitamin D deficiency: an optimized intelligent Bayesian network algorithm analysis of a stratified randomized controlled field trial

This study aimed to elucidate the algorithm of various influential factors relating to the association between 25-hydroxyvitamin D (25(OH)D) concentration at delivery and mode of delivery. The investigation constituted a secondary analysis using data collected as part of the Khuzestan Vitamin D Deficiency Screening Program in Pregnancy, which is a stratified randomized vitamin D supplementation-controlled trial comprising 1649 eligible pregnant women. The Bayesian Network (BN) method was utilized to determine the association algorithm between diverse influential factors associated with maternal vitamin D and mode of delivery. The optimized intelligent BN algorithm revealed that women presenting with moderate (35.67%; 95% CI: 33.36-37.96) and severe vitamin D deficiency (47.22%; 95% CI: 44.81-49.63) at delivery were more likely to undergo cesarean section than those presenting with normal concentrations of this nutritional hormone (18.62%; 95% CI: 16.74-20.5). The occurrence probabilities of preeclampsia in mothers with normal, moderate, and severe vitamin D deficiency at delivery were (1.5%; 95% CI: 0.92-2.09), (14.01%; 95% CI: 12.33-15.68), and (26.81%; 95% CI: 24.67-28.95), respectively. Additionally, mothers with moderate (11.81%; 95% CI: 10.25-13.36) and severe (27.86%; 95% CI: 25.69-30.02) vitamin D deficiency exhibited a higher probability of preterm delivery in comparison to those presenting with normal concentrations (1.12%; 95% CI: 0.62-1.63). This study demonstrated that the vitamin D status of pregnant women at delivery could directly affect the mode of delivery and indirectly through maternal complications, such as preeclampsia and preterm delivery, leading to a higher occurrence probability of cesarean section.

Joint Exposure to Ambient Air Pollutants Might Elevate the Risk of Small for Gestational Age (SGA) Infants in Wuhan: Evidence From a Cross-Sectional Study

Objective: To investigate the effect of exposure to multiple ambient air pollutants during pregnancy on the risk of children being born small for gestational age (SGA). Methods: An Air Pollution Score (APS) was constructed to assess the effects of being exposed to six air pollutants simultaneously, PM_2.5, PM₁₀, SO₂, NO₂, CO, and O₃ (referred to as joint exposure). A logistic regression model was applied to estimate the associations of APS and SGA. Results: The adjusted odds ratios (ORs) of SGA per 10 ug/m³ increased in APS during the first and second trimesters and the entire pregnancy were 1.003 [95% confidence intervals (CIs): 1.000, 1.007], 1.018 (1.012, 1.025), and 1.020 (1.009, 1.031), respectively. The ORs of SGA for each 10 μg/m³ elevated in APS during the whole pregnancy were 1.025 (1.005, 1.046) for mothers aged over 35 years old vs. 1.018 (1.005, 1.031) for mothers aged under 35 years old. Women who were pregnant for the first time were more vulnerable to joint ambient air pollution. Conclusion: In summary, the results of the present study suggested that joint exposure to ambient air pollutants was associated with the increment in the risks of SGA.

Maternal vitamin D deficiency aggravates the dysbiosis of gut microbiota by affecting intestinal barrier function and inflammation in obese male offspring mice

OBJECTIVES

The colonization of gut microbiota during early life may play a critical role in the progression of metabolic syndrome in adulthood. Targeting gut-based genes in the barrier function, inflammation, and lipid transportation are potential therapies for obesity. Therefore, this study focused on whether maternal deficient vitamin D (VD) intake could aggravate the dysbiosis of gut microbiota by affecting the expressions of these genes in the ileum and colon of obese male offspring mice.

METHODS

Four-week-old female C57 BL/6 J mice were fed normal (VD-C) or VD-deficient (VD-D) reproductive diets throughout pregnancy and lactation (n = 15/group). Weaning male pups (n = 10/group) were fed either a high-fat (HFD; VD-C-HFD, VD-D-HFD) or normal-fat diet (control) for 16 wk. All biologic samples were obtained after the mice were anesthetized by cervical dislocation. Subsequently, the compositions of the gut microbiota in cecal contents were analyzed using 16 S ribosomal RNA sequencing. Messenger RNA expression in the ileum and colon was determined using real-time reverse transcription-polymerase chain reaction. The distributions of ZO-1 and Claudin-1 were determined using immunohistochemistry testing.

RESULTS

Maternal deficient VD intake significantly aggravated the dysbiosis of gut microbiota persisting into adulthood from phylum to genus levels in the cecal contents among obese male offspring mice. This aggravation led to significantly depleted Bacteroidetes and Verrucomicrobia (Akkermansia, Alliprevotella, and Bacteroides), with higher relative abundance of Firmicutes (Lactobacillus, Lachnoclostridium, Romboutsia, and Ruminiclostridium_9) and Firmicutes/Bacteroidetes. The gene expressions of proinflammatory cytokines (Ccl2, Ccl4 and interleukin-1β) and lipid transportation molecules (Ffar3, Fabp4, and Fabp1) were higher, and the levels of intestinal barrier function (Occludin, ZO-1, and Claudin-1) were lower in the VD-D-HFD group than those in the VD-C-HFD group. Furthermore, there were significant correlations between the dysbiosis of intestinal microbials and expressions of genes related to barrier function, inflammation, and lipid transportation in the ileum and/or colon.

CONCLUSIONS

Maternal VD deficiency during pregnancy and lactation could aggravate the dysbiosis of gut microbiota to affect the progression of obesity among male offspring, which might be regulated by genes associated with barrier function, inflammation, and lipid transportation. So early life appropriate VD intake could play a significant role in preventing later obesity.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association between Suboptimal 25-Hydroxyvitamin D Status and Overweight/Obesity in Infants: A Prospective Cohort Study in China

This study aimed to investigate whether 25-hydroxyvitamin D (25(OH)D) concentrations are correlated to overweight/obesity in infants and to explore a threshold of 25(OH)D. A total of 1205 six-month-old infants from two community hospitals in Shanghai were randomly recruited, and 925 of them were followed up at 12 months. Concentration of 25(OH)D, weight, and length were measured at two time points. Overweight/obesity was defined as a weight-for-length Z-score >97th percentile. The prevalence of overweight/obesity at 6 and 12 months was 6.88% and 5.26%, respectively. The occurrence of vitamin D (VitD) deficiency (<20 ng/mL) at 6 and 12 months was 6.56% and 2.05%, respectively. Concentration of 25(OH)D at the corresponding age was negatively associated with weight-for-length percentile (WLP) at both 6 (adjusted β: −0.14; 95% CI: −0.27, −0.02; p = 0.02) and 12 months (adjusted β: −0.22; 95% CI: −0.41, −0.02; p = 0.03), while the relationship between 25(OH)D at 6 months and WLP at 12 months was nonlinear, where 35 ng/mL was identified as an inflection point. Those with a concentration of 25(OH)D <35 ng/mL at 6 months had a higher risk of overweight/obesity (adjusted OR: 1.42; 95% CI: 1.06, 1.91; p = 0.02) compared to the group with a concentration of 25(OH)D ≥35 ng/mL. Moreover, a concentration of 25(OH)D <35 ng/mL at two time points significantly increased the risk of overweight/obesity at 12 months compared to the group with 25(OH)D concentration ≥35 ng/mL at two time points (adjusted OR: 2.91; 95% CI: 1.13, 7.46; p = 0.03). A suboptimal 25(OH)D concentration <35 ng/mL significantly increases the risk of overweight/obesity in infants.

Maternal fish and shellfish consumption and preterm birth: a retrospective study in urban China

Preterm birth is the leading cause of perinatal mortality and morbidity. Some prospective cohort studies suggested that fish and shellfish consumption may affect the incidence of preterm birth. However, conflicting evidence exists on the relationship between fish and shellfish consumption and preterm birth. A total of 10 179 women from Gansu province were interviewed after delivery to collect information on their past intake of fish and shellfish using FFQ. Logistic regression models were used to estimate OR and 95 % CI to examine the association between fish and shellfish consumption and preterm birth and its clinical subtypes. Fish and shellfish consumption was associated with reduced risk of preterm birth (OR = 0·65, 95 % CI 0·56, 0·77). Increasing frequency of fish and shellfish consumption, compared with no fish and shellfish consumption, was associated with decreasing odds of preterm birth. Besides, increasing weekly total amount of fish and shellfish consumption, compared with no fish and shellfish consumption, was also associated with decreasing odds of preterm birth. Significant trend effect was also seen between fish and shellfish consumption and very preterm birth (P_{for trend} = 0·001) and spontaneous preterm birth (P_{for trend} = 0·003). Interaction was observed between total fish and shellfish consumption with maternal age (P_{for interaction} = 0·041) and pre-pregnancy BMI underweight (P_{for interaction} = 0·012). Our findings showed that maternal fish and shellfish consumption was associated with lower incidence of preterm birth.We recommend for the national guideline of ≥350 g/week of fish and shellfish consumption among pregnant women.

Vitamin D Supplementation Improves Mitochondrial Function and Reduces Inflammation in Placentae of Obese Women

Background

About 30% of women entering pregnancy in the US are obese. We have previously reported mitochondrial dysregulation and increased inflammation in the placentae of obese women. Vitamin D (VitD) is a major player in calcium uptake and was shown to modulate mitochondrial respiration and the immune/inflammation system. Studies show decreased VitD levels in obese individuals; however, the effect of maternal obesity on VitD metabolism and its association with placental function remains understudied.

Methods

Maternal and cord blood plasma and placental samples were collected upon C-section from normal-weight (NW, body mass index [BMI]<25) and obese (OB, BMI>30) women with uncomplicated pregnancies at term. We measured 25(OH)D3 (calcidiol) levels in maternal and cord blood plasma using ELISA. We assessed the expression of CYP27B1, an activator of calcidiol, and Vitamin D receptor (VDR) in placentae from NW and OB, and women with gestational diabetes and preeclampsia. In addition, we examined the effects of VitD supplementation on mitochondrial function and inflammation in trophoblasts from NW and OB, using the Seahorse Bioanalyzer and Western blot, respectively.

Results

Vitamin D levels in blood from OB but not NW women and in cord blood from babies born to NW and OB women showed a significant inverse correlation with maternal pre-pregnancy BMI (r=-0.50, p<0.1 and r=-0.55, p=0.004 respectively). Cord plasma VitD levels showed a positive correlation with placental efficiency, i.e., the ratio between fetal and placental weight, as well as with maternal blood VitD levels (r=0.69 and 0.83 respectively, p<0.00). While we found no changes in CYP27B1 in OB vs. NW women, VDR expression were decreased by 50% (p<0.03) independent of fetal sex. No changes in VDR expression relative to BMI-matched controls were observed in the placentae of women with gestational diabetes or preeclampsia. Cytotrophoblasts isolated from placentae of OB women showed a dose-dependent increase in VDR expression after 24-hour treatment with calcitriol (10 nM and 100 nM), an active form of VitD. Trophoblasts isolated from OB women and treated with calcitriol improved mitochondrial respiration (p<0.05). We also found a two-fold increase in expression of the NLRP3 inflammasome and the pro-inflammatory cytokine IL-18 in trophoblasts isolated from placentae of OB women (p<0.05), with IL-18 expression being reversed by calcitriol treatment (100 nM).

Conclusions

We show that VitD deficiency is at least partially responsible for mitochondrial dysfunction and increased inflammation in the placentae of obese women. Vitamin D supplementation could be beneficial in improving placental dysfunction seen in obese women.

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.

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.

The Influence of Maternal Levels of Vitamin D and Adiponectin on Anthropometrical Measures and Bone Health in Offspring

BACKGROUND

From the conception onward, certain parameters associated with maternal health may affect foetal body composition, growth and bone mineral content. The objective of the study was to determine the association between maternal vitamin D and adiponectin status with the anthropometrical measures of newborns, and bone health status measured by Quantitative Ultrasound (QUS) at birth.

METHODS

Circulating 25OHD and adiponectin concentration were measured in 73 pregnant women. Correlations with the anthropometrical measures and bone health status in their infants were studied. Bone health was evaluated using QUS with the measurements of speed of sound (SOS, in m/s) and Z score on the right tibia.

RESULTS

There was no significant association between maternal 25OHD and newborn's anthropometrical measures at birth (weight p=0.35, length p=0.59 and head circumference p=0.47). There was a significant negative correlation between a maternal serum adiponectin and a) weight of infants at birth (R= -0.37, p=0.002); b) birth length (R= -0.31, p=0.008) and c) head circumference (R= -0.29, p=0.014). There was no significant correlation between maternal 25OHD blood levels during pregnancy and SOS in newborns (p=0.48). Additionally, a correlation between maternal adiponectin concentration during pregnancy and SOS in newborns was not significant (p=0.82).

CONCLUSION

Although a high prevalence of low 25OHD level among pregnant women was found, maternal vitamin D status did not influence growth and bone health of their offspring at birth. Maternal adiponectin levels in plasma showed an inverse relationship with anthropometrical measures of infants at birth, while no correlation with the newborn's bone health was found.

Association of Maternal Prepregnancy Weight and Gestational Weight Gain With Children's Allergic Diseases

IMPORTANCE

Information on the association between maternal prepregnancy body weight, gestational weight change, and childhood allergies is not consistent. Little is known on whether there is a combined association with comprehensive childhood allergies.

OBJECTIVE

To examine the association of maternal prepregnancy body mass index and gestational weight gain (GWG) with the risk of childhood allergic diseases including asthma and/or wheezing, allergic rhinitis, eczema, and food and/or drug allergy.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was conducted from April 12 to June 1, 2019, using the Shanghai Children Allergy Study (SCAS), a large, population-based survey. A multistage and multistrata sampling approach was applied to conduct the survey in 13 districts across Shanghai, China, with an enrollment of 15 145 mother-child pairs.

EXPOSURES

Reported maternal weight before pregnancy and at the time of delivery were requested in the survey; GWG was examined in absolute terms and with reference to the Institute of Medicine guideline.

MAIN OUTCOMES AND MEASURES

The ascertainment of allergic diseases was based on the International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

Among 15 145 children aged 3 to 14 years (7911 [52.2%] boys) within the SCAS, 8877 children (58.6%) were screened for allergic diseases. Multivariable log-binomial regression models suggested that excessive GWG was associated with risks of 19% for asthma/wheezing, 11% for allergic rhinitis, and 10% for eczema in the children. Gestational weight gain extremely above the Institute of Medicine guideline in women who were overweight/obese before pregnancy was associated with the highest risk of childhood asthma/wheezing (adjusted prevalence ratio, 1.42; 95% CI, 1.16-1.74; P = .001), allergic rhinitis (adjusted prevalence ratio, 1.32; 95% CI, 1.12-1.56; P = .001), and eczema (adjusted prevalence ratio, 1.24; 95% CI, 1.08-1.41; P = .002). Gestational weight gain below the Institute of Medicine guideline was associated with an attenuated risk of 13% for childhood asthma/wheezing, 11% for allergic rhinitis, 14% for eczema, and 15% food/drug allergy when mothers were of prepregnancy normal weight; similar associations were observed in underweight mothers, but there was no association in overweight mothers. Generally, the associations were similar in the stratified analysis according to children's age group. Moreover, the results were similar in the allergen test subgroup.

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that excessive GWG may be a risk factor for childhood allergic diseases. Further studies on the long-term effects of the intrauterine environment on children's health may take maternal weight management during pregnancy into consideration since GWG could be a controllable and modifiable risk factor.

Associations between prenatal sunshine exposure and birth outcomes in China

This paper is one of the first to examine the associations between prenatal sunshine exposure and birth outcomes, specifically the incidence of low birth weight (LBW) and small for gestational age (SGA), based on a nationally representative birth record dataset in China. During the sample period in the 1990s, migration was limited in rural China, allowing us to address the identification challenges, like residential sorting and avoidance behaviors. We found a nonlinear relationship between the length of sunlight and birth outcomes. In particular, prenatal exposure to increasing sunshine was associated with a reduction in the incidence of LBW and SGA, especially in the second trimester during pregnancy. This finding was consistent with the clinical evidence suggesting positive effects of sunshine on birth outcomes via obtaining vitamin D or relieving maternal stress.

Prevalence of vitamin D deficiency in pregnant women and their babies in Bhaktapur, Nepal

Background

Vitamin D deficiency has been observed worldwide in pregnant women and their newborns. Maternal vitamin D deficiency can lead to deficiency in their newborn baby and has been linked with various complications during pregnancy and delivery. There is risk of premature delivery and it is associated with high neonatal mortality.

Methods

Seventy-nine pregnant women who were admitted to the Siddhi Memorial Hospital for delivery and their newborn babies were enrolled in the study. Maternal blood samples were taken before delivery while umbilical cord blood samples of their babies were taken after delivery. Serum vitamin D level and calcium level were assessed by fluorescence immunoassay using Ichromax vitamin D kit and endpoint method, respectively in the Siddhi Memorial Hospital laboratory.

Results

Mean +/− SD serum vitamin D and calcium levels in pregnant mother before delivery were 14.6 +/− 8.5 ng/ml and 8.0 +/− 0.5 mg/dl, respectively, and in the cord blood were 25.7 +/− 11.2 ng/ml and 8.6 +/− 0.9 mg/dl, respectively. Eighty-one percent of the mothers and 35.8% of their babies were found to have vitamin D deficiency. Although 97.5% of the pregnant women were taking calcium supplementation, serum calcium was found lower than the normal reference value in 67% of the pregnant women and 64.2% of their babies. There were a linear relationship between the maternal and baby’s serum vitamin D (P < 0.001) and calcium (P < 0.001) levels.

Conclusion

There is high prevalence of vitamin D and calcium deficiency in pregnant mothers and newborn babies in Bhaktapur, Nepal. Pregnant women need to be supplemented with adequate amounts of these nutrients.

The Relationship between First Trimester 25-Hydroxyvitamin D3 Levels and Second Trimester Femur Length and Their Effects on Birth Weight and Length at Birth: A Preliminary Study

Objective

The main goal of our study was to assess relationships between first trimester 25-hydroxyvitamin D3 levels and infant birthweight and length at birth.

Materials and Methods

We conducted a study over our medical records of 154 live-term births at Acibadem Atakent Hospital, Istanbul, Turkey. Subjects were classified into five independent groups.

Results

We retrospectively reviewed a total of 154 live birth records. They took vitamin D3 supplement 1000 U/day. We classified the serum vitamin D levels into 5 groups by concentration. Group 1 comprised serum vitamin D levels <10 ng/ml (n = 41); group 2 comprised serum Vitamin D levels between >10–16 ng/ml (n = 33); group 3 comprised serum vitamin D levels >16–20 ng/ml (n = 26); group 4 vitamin D level between >20–30 ng/ml (n = 33) and group 5 comprised vitamin D levels >30 ng/ml. The femurs of infants were found to be longer between the groups, although the differences were not significant (p=0.054). There was also a statistically significant difference in the neonatal birth weight (p=0.048).

Conclusion

We observed associations between low and high maternal 25-hydroxyvitamin D3 levels and fetal growth at birth weight but no difference in birth length. We conclude that we always need to conduct further research to be able to predict the effects of vitamin D deficiency.

High Prevalence of Maternal Serum 25-Hydroxyvitamin D Deficiency Is Not Associated With Poor Birth Outcomes Among Healthy White Women in the Pacific Northwest

OBJECTIVE

To quantify vitamin D status among pregnant women in the Pacific Northwest (Portland, OR, and Seattle, WA) and examine pregnancy and newborn outcomes in relationship to maternal serum blood samples obtained during pregnancy.

DESIGN

A retrospective cohort design.

SETTING

Data from 2009 to 2013 were abstracted from the health records of two out-of-hospital midwifery practices in the Pacific Northwest.

PARTICIPANTS

Women with recorded serum blood samples for vitamin D during pregnancy were included. We reviewed health records of 663 women, and 357 met criteria.

METHODS

We extracted demographic, biometric, and pregnancy outcome data from participants' records and analyzed them using regression models.

RESULTS

Mean serum 25-hydroxy vitamin D (25[OH]D) was 29.96 ± 10.9 ng/ml; 45.5% of participants were sufficient (≥30 ng/ml), and 55.5% were insufficient or deficient (<29 ng/ml). Lower vitamin D levels were predicted by Seattle location, greater prepregnancy body mass index, and blood samples drawn during the winter. Vitamin D status was not a predictor of spontaneous abortion, glucose tolerance test result, cesarean birth, infant birth weight, or any other outcome investigated.

CONCLUSION

Although there is a high prevalence of vitamin D insufficiency and deficiency in pregnant women in the Pacific Northwest, adverse health effects were not observed. This may be attributable to the overall healthy profile of the women in our sample. Further research on maternal vitamin D status should focus on identification of optimal vitamin D levels in pregnancy and long-term outcomes among offspring of women who are vitamin D deficient, particularly those from high-risk, vulnerable populations.

Seasonal analyses of the association between prenatal ambient air pollution exposure and birth weight for gestational age in Guangzhou, China

Ambient air pollution has been linked to small for gestational age (SGA); however, the relationship with large for gestational age (LGA) is unclear and very few studies have investigated seasonal effects on the association between air pollution and SGA or LGA. Using birth registry data of 506,000 singleton live births from 11 districts in Guangzhou, China between January 2015 and July 2017, we examined associations between ambient air pollutants (PM_2.5, PM₁₀, NO₂, SO₂, and O₃) and SGA/LGA, and further assessed the modification effect of season. Daily concentrations of air pollutants from 11 monitoring stations were used to estimate district-specific exposures for each participant based on their district of residence during pregnancy. Two-level binary logistic regression models were used to evaluate associations between air pollution and SGA/LGA. Stratified analyses by season and a Cochran Q test were performed to assess the modification of season. Exposure to PM_2.5, NO₂, SO₂, and O₃ was significantly associated with increased risk of SGA, especially for exposure during the second and third trimester. For an interquartile range (IQR) increase in PM_2.5 (6.5 μg/m³), NO₂ (12.7 μg/m³), SO₂ (2.8 μg/m³) and O₃ (20.8 μg/m³) during the entire pregnancy, SGA risk increased by 2% (OR = 1.02, 95% CI: 1.00-1.04), 8% (OR = 1.08, 95% CI: 1.04-1.12), 2% (OR = 1.02, 95% CI: 1.01-1.03), and 14% (1.14, 1.11-1.17), respectively. A decreased risk of LGA was found for PM_2.5, PM₁₀, SO₂, and O₃ during the first trimester or entire pregnancy. When examined by season, significant associations between air pollutants and SGA were observed for women who conceived during summer or fall, and the patterns were consistent for all pollutants. Our study suggests that conception during different seasons might modify the association between ambient air pollution and SGA.

The Association between Household Socioeconomic Status, Breastfeeding, and Infants' Anthropometric Indices

BACKGROUND

The growth, learning, and contribution to active life in the communities are better in well-nourished children, and various factors influence infants' feeding. In this study, we assessed whether household socioeconomic status (SES) affects infants' length-for-age, weight-for-age (indicators of health and nutritional status) and breastfeeding (BF) (a necessity for optimal growth and health) status.

METHODS

In this cross-sectional study, 150 households with infants of 1-1.5 years old were interviewed on these variables: family size, dwelling ownership, duration of BF, exclusive BF (EBF) for 6 months, parents' age, parents' ethnicity, birth order, delivery type, and parents' education. Weight and length at 4 and 12 months were obtained from centers' records. To determine SES, we assessed total years of parents' education and household asset ownership by an index of nine owned assets.

RESULTS

The average of 4-month length in the low SES group was significantly lower than the two others (P < 0.05). In middle socioeconomic group, duration of BF was significantly higher (19.5 ± 7.3 months vs. 18.0 ± 8.0 months in low and 17.5 ± 7.9 months in high SES groups) (P < 0.05). Comparing illiterate mothers, university degree holders and university students were 73% less likely to not having EBF. Moreover, those with middle SES showed to be about 40% less likely to not having EBF.

CONCLUSIONS

Nutritional status, duration of BF, and EBF might be determined by household SES and maternal education. Therefore, these findings can be used to decide how to focus on appropriate target groups in family education planning to improve children's development to its most possible.

Racial difference in preterm birth and low birthweight: Towards a new hypothesis involving the interaction of 25-hydroxyvitamin D with maternal fat mass

Preterm birth (PB) and low birthweight (LBW) remain a leading cause of infant mortality worldwide. Persistent racial disparities in prevalence rates have been reported, with the highest values observed in Subsaharan Africa and South Asia. In United States, non-Hispanic Black women are more likely to have a premature or low-birth-weight baby. Beyond the speculative debate on factors explaining such racial disparity, the key-question remains about the path from race to birth outcomes. Several hypotheses emerged from the published literature to explain the racial difference in likelihood for PB and LBW. However, the 'Hispanic paradox' remains unexplained. We relied here on published data to hypothesize that the racial disparity in PB/LBW is a consequence to the joint influence of 25-hydroxyvitamin D and fat mass. Beyond its role as a source of 1,25-dihydroxyvitamin D, the 25-hydroxyvitamin D is directly implicated in the fetal growth and the normal completion of pregnancy. Because of its lipophilic property, a large part of 25-hydroxyvitamin D is swiftly trapped into fat mass and the circulating fraction impact the body development during fetal period. We postulate that the positive effect of vitamin D to prevent PB/LBW is less beneficial for women with high fat mass, independent of race. The core problem may be related to bioavailable 25-hydroxyvitamin D, not directly to race.

Longitudinal measures of maternal vitamin D and neonatal body composition

Background/Objectives

Vitamin D status has been associated with fetal growth and offspring’s bone mass in some observational studies. We characterize the trajectory of total maternal serum 25-hydroxyvitamin D [25(OH)D] concentration by race and examine whether vitamin D status is associated with neonatal anthropometry and body composition as assessed by dual energy X-ray absorptiometry (DXA).

Methods

Three longitudinal pregnancy samples from the Memphis site of the Calcium for Preeclampsia Prevention trial (1992-1995) were used. Racial differences in total 25(OH)D trajectories (n=343 women) were tested using an interaction term between blood draw gestational week and race in linear mixed-effects models. Linear regression and linear mixed-effects models estimated adjusted associations between total 25(OH)D concentration with neonatal anthropometry and body composition (n=252 with DXA), including interactions with infant sex and serum calcium.

Results

Total 25(OH)D concentration increased with gestational age but its trajectory over pregnancy did not differ between African-American and Caucasian women. Deficient maternal vitamin D (25(OH)D concentration <20 ng/ml) was associated with lower neonatal total bone mineral density (β −0.009 g/cm²; 95% CI −0.016, −0.002). Among male newborns, deficiency was also associated with lower lean mass (−217 g; −391, −43) and birthweight (−308 g; −540, −76). Deficient maternal vitamin D was also associated with lower ponderal index (β –2.3 kg/m³; 95% CI −4.0, −0.5) among those in the lowest calcium tertile.

Conclusion

Vitamin D deficiency during pregnancy is associated with lower bone density and smaller size at birth in certain subgroups suggesting its importance in fetal development.

Periodontal diseases and adverse pregnancy outcomes: Is there a role for vitamin D?

Studies have shown a relationship between maternal periodontal diseases (PDs) and premature delivery. PDs are commonly encountered oral diseases which cause progressive damage to the periodontal ligament and alveolar bones, leading to loss of teeth and oral disabilities. PDs also adversely affect general health by worsening of cardiovascular and metabolic diseases. Moreover, maternal PDs are thought to be related to increasing the frequency of preterm-birth with low birth weight (PBLBW) in new-borns. Prematurity and immaturity are the leading causes of prenatal and infant mortality and is a major public health problem around the world. Inflamed periodontal tissues generate significantly high levels of proinflammatory cytokines that may have systemic effects on the host mother and the fetus. In addition, the bacteria that cause PDs produce endotoxins which can harm the fetus. Furthermore, studies have shown that microorganisms causing PDs can get access to the bloodstream, invading uterine tissues, to induce PBLBW. Another likely mechanism that connects PDs with adverse pregnancy outcome is maternal vitamin D status. A role of inadequate vitamin D status in the genesis of PDs has been reported. Administration of vitamin D supplementation during pregnancy could reduce the risk of maternal infections and adverse pregnancy outcomes. As maternal PDs are significant risk factors for adverse pregnancy outcome, preventive antenatal care for pregnant women in collaboration with the obstetric and dental professions are required.

Altered downstream target gene expression of the placental Vitamin D receptor in human idiopathic fetal growth restriction

Fetal growth restriction (FGR) affects up to 5% of pregnancies and is associated with significant perinatal complications. Maternal deficiency of vitamin D, a secosteroid hormone, is common in FGR-affected pregnancies. We recently demonstrated that decreased expression of the vitamin D receptor (VDR) in idiopathic FGR placentae could impair trophoblast growth. As strict regulation of cell-cycle genes in trophoblast cells is critical for optimal feto-placental growth, we hypothesised that pathologically decreased placental VDR contributes to aberrant regulation of cell-cycle genes. The study aims were to (i) identify the downstream cell-cycle regulatory genes of VDR in trophoblast cells, and (ii) determine if expression was changed in cases of FGR. Targeted cell-cycle gene cDNA arrays were used to screen for downstream targets of VDR in VDR siRNA-transfected BeWo and HTR-8/SVneo trophoblast-derived cell lines, and in third trimester placentae from FGR and gestation-matched control pregnancies (n = 25 each). The six candidate genes identified were CDKN2A, CDKN2D, HDAC4, HDAC6, TGFB2 and TGFB3. TGFB3 was prioritised for further validation, as its expression is largely unknown in FGR. Significantly reduced mRNA and protein expression of TGFB3 was verified in FGR placentae and the BeWo and HTR-8/SVneo trophoblast cell lines, using real-time PCR and immunoblotting respectively. In summary, decreased placental VDR expression alters the expression of regulatory cell-cycle genes in FGR placentae. Aberrant regulation of cell-cycle genes in the placental trophoblast cells may constitute a mechanistic pathway by which decreased placental VDR reduces feto-placental growth.

Association between Vitamin Intake during Pregnancy and Risk of Small for Gestational Age

Pregnancy increases the requirements of certain nutrients, such as vitamins, to provide nutrition for the newborn. The aim was to analyze the association between dietary intake of vitamins during pregnancy and risk of having a small for gestational age (SGA) newborn. A matched case-control study was conducted (518 cases and 518 controls of pregnant women) in Spain. Dietary vitamin intake during pregnancy was assessed using a validated food frequency questionnaire, categorized into quintiles. Odds ratios (ORs) and their 95% confidence intervals (CI) were estimated with conditional regression logistic models. A protective association was observed between maternal dietary intake of vitamins A and D and SGA. For vitamin B3 and B6, the observed protective effect was maintained after adjusting for potential confounding factors. For vitamin B9, we found only an effect in quintiles 3 and 4 (OR = 0.64; 95% CI, 0.41-1.00; OR = 0.58; 95% CI, 0.37-0.91). Protective effect for vitamin B12 was observed in 4th and 5th quintiles (OR = 0.61; 95% CI, 0.39-0.95; OR = 0.68; 95% CI, 0.43-1.04). No associations were detected between dietary intake of vitamins B2, E and C intake and SGA. Our results suggest a positive association between dietary vitamin intake during pregnancy and the weight of the newborn, although more studies are necessary and there could be a ceiling effect for higher intakes of some vitamins cannot be discarded.

Maternal obesity and childhood wheezing and asthma

Obesity represents one of the major public health problems worldwide, with an increased prevalence also among women of reproductive age. Maternal pre-pregnancy overweight and obesity are important risk factors for a number of maternal and foetal/neonatal complications. The objective of this review is to provide an overview of the most recent evidence regarding the associations between pre-pregnancy overweight/obesity and wheezing and asthma in childhood. Potential mechanisms, mediators and confounding factors involved in these associations are also discussed. Despite the relatively large body of studies examining these associations and taking into account main confounders and potential mediators, the causal relationship between maternal obesity and wheezing and asthma in childhood is still uncertain. This uncertainty is not trivial, as any prevention strategy aimed at reducing the burden of these conditions would necessarily imply better understanding of the factors that are in the causal chain.

Effect of Prenatal versus Postnatal Vitamin D Deficiency on Pulmonary Structure and Function in Mice

Epidemiologic studies have linked gestational vitamin D deficiency to respiratory diseases, although mechanisms have not been defined. We hypothesized that antenatal vitamin D deficiency would impair airway development and alveolarization in a mouse model. We studied the effect of antenatal vitamin D deficiency by inducing it in pregnant mice and then compared lung development and function in their offspring to littermate controls. Postnatal vitamin D deficiency and sufficiency models from each group were also studied. We developed a novel tracheal ultrasound imaging technique to measure tracheal diameter in vivo. Histological analysis estimated tracheal cartilage total area and thickness. We found that vitamin D-deficient pups had reduced tracheal diameter with decreased tracheal cartilage minimal width. Vitamin D deficiency increased airway resistance and reduced lung compliance, and led to alveolar simplification. Postnatal vitamin D supplementation improved lung function and radial alveolar count, a parameter of alveolar development, but did not correct tracheal narrowing. We conclude that antenatal vitamin D deficiency impairs airway and alveolar development and limits lung function. Reduced tracheal diameter, cartilage irregularity, and alveolar simplification in vitamin D-deficient mice may contribute to increased airways resistance and diminished lung compliance. Vitamin D supplementation after birth improved lung function and, potentially, alveolar simplification, but did not improve defective tracheal structure. This mouse model offers insight into the mechanisms of vitamin D deficiency-associated lung disease and provides an in vivo model for investigating preclinical preventive and therapeutic strategies.

Micronutrient Intake Is Inadequate for a Sample of Pregnant African-American Women

BACKGROUND

Micronutrient intake is critical for fetal development and positive pregnancy outcomes. Little is known about the adequacy of micronutrient intake in pregnant African-American women.

OBJECTIVE

To describe nutrient sufficiency and top food groups contributing to dietary intake of select micronutrients in low-income pregnant African-American women and determine whether micronutrient intake varies with early pregnancy body mass index (BMI) and/or gestational weight gain.

DESIGN

Secondary analysis of data collected in a cohort study of pregnant African-American women.

PARTICIPANTS/SETTING

A total of 93 women aged 18 to 36 years, <20 weeks pregnant, with early pregnancy BMIs ≥18.5 and <40.0. The study was conducted during 2008 to 2012 with participants from university-affiliated obstetrics clinics in an urban setting in the northeastern United States.

MAIN OUTCOME MEASURES

Proportion of women with dietary intakes below Estimated Average Requirement (EAR) or Adequate Intake (AI) for vitamin D, folate, iron, calcium, and choline throughout pregnancy. Top food groups from which women derived these micronutrients was also determined.

STATISTICAL ANALYSES PERFORMED

Descriptive statistics included means, standard deviations, and percentages. Percent of women reaching EAR or AI was calculated. The χ² test was used to assess micronutrient intake differences based on early pregnancy BMI and gestational weight gain.

RESULTS

A large percentage of pregnant women did not achieve the EAR or AI from dietary sources alone; EAR for folate (66%), vitamin D (100%), iron (89%), and AI for choline (100%). Mean micronutrient intake varied throughout pregnancy. Top food sources included reduced-fat milk, eggs, and mixed egg dishes, pasta dishes, and ready-to-eat cereal.

CONCLUSIONS

The majority of study participants had dietary micronutrient intake levels below EAR/AI throughout pregnancy. Findings suggest that practitioners should evaluate dietary adequacy in women to avoid deficits in micronutrient intake during pregnancy. Top food sources of these micronutrients can be considered when assisting women in improving dietary intake.

[High prevalence of inadequate calcium and vitamin D dietary intake in two cohorts of pregnant women]

This study aimed to identify the prevalence of inadequate calcium and vitamin D dietary intake and related factors in two cohorts of pregnant women according to trimester of pregnancy. Two 24-hour dietary recall tests were taken in each trimester, one pertaining to weekends. Variables significantly correlated with intake of these nutrients were included in a multivariate linear regression model, adjusted for energy. Prevalence of inadequate intake was estimated according to the National Cancer Institute method (United States). In cohort A, inadequate vitamin D did not differ between trimesters; in B there was a reduction: from 99.7% in the first trimester to 97.1% in the third. In cohorts A and B, inadequate calcium intake exceeded 70%, falling slightly from the first (89.2% and 81.4%) to the second (79.7% and 69.1%) and third trimesters (82.7% and 72.6%). There was no correlation between maternal variables and the intake of these micronutrients. In conclusion, intake of vitamin D and calcium is seriously inadequate and distributed homogeneously among pregnant women in the primary healthcare network.

Daily Cholecalciferol Supplementation during Pregnancy Alters Markers of Regulatory Immunity, Inflammation, and Clinical Outcomes in a Randomized Controlled Trial

BACKGROUND

Vitamin D deficiency is widespread in pregnancy and has been associated with adverse health conditions in mothers and infants. Vitamin D supplementation in pregnancy may support the maintenance of pregnancy by its effects on innate and adaptive immunity.

OBJECTIVE

We assessed the effects of vitamin D supplementation during pregnancy on vitamin D status and markers of immune function associated with adverse pregnancy outcomes.

METHODS

We conducted a randomized, controlled, double-blind intervention of 2 doses of cholecalciferol (400 and 2000 IU/d) from <20 wk to delivery in 57 pregnant women. Vitamin D status, regulatory and inflammatory T cells, markers of innate immunity and systemic inflammation, and clinical outcomes including maternal blood pressure and birth weight were assessed at 26 and 36 wk of pregnancy.

RESULTS

Supplementation with 2000 IU/d vitamin D had a greater effect on the change in vitamin D status over pregnancy (P < 0.0001) and the final value at 36 wk (P < 0.0001) than 400 IU/d, increasing serum 25-hydroxyvitamin D from 81.1 nmol/L at baseline to 116 nmol/L at 36 wk and from 69.6 nmol/L at baseline to 85.6 nmol/L at 36 wk, respectively. The 2000-IU/d group had 36% more interleukin-10⁺ regulatory CD4⁺ T cells at 36 wk than did the 400-IU/d group (P < 0.007). The daily intake of 2000 compared with 400 IU/d tended to dampen the pregnancy-related increase in diastolic blood pressure by 1.3-fold (P = 0.06) and increase birth weight by 8.6% (P = 0.06), but these differences were not statistically significant.

CONCLUSIONS

Supplementation with 2000 IU/d is more effective at increasing vitamin D status in pregnant women than 400 IU/d and is associated with increased regulatory T cell immunity that may prevent adverse outcomes caused by excess inflammation. This trial was registered at clinicaltrials.gov as NCT01417351.

Maternal Vitamin D Status at Week 30 of Gestation and Offspring Cardio-Metabolic Health at 20 Years: A Prospective Cohort Study over Two Decades

Background/Objectives

Vitamin D deficiency is common among pregnant women and since the fetus relies exclusively on maternal supply, deficiency could potentially interfere with fetal development. Vitamin D blood concentrations during pregnancy have been associated with offspring cardio-metabolic health in a few previous studies but the evidence is still inconsistent and only one previous study has followed the offspring into adulthood. The aim of the present study was to investigate the association between maternal serum concentration of vitamin D (25(OH)D) in week 30 of gestation and offspring cardio-metabolic risk factors at 20 years.

Subjects/Methods

A follow up study of a Danish birth cohort from 1988–89 (n = 965) was conducted. A blood sample was drawn from the women in week 30 of gestation. In 2008–2009, 95% of the original mother and child dyads could be identified in the central registration registry and were alive and living in Denmark. The offspring were followed up with self-reported anthropometrics (N = 629, 69%) and a clinical examination (N = 410, 45%). Multiple linear regression was used to estimate the association between maternal 25(OH)D and offspring cardio-metabolic risk factors adjusting for potential confounders.

Results

No overall association was observed between maternal 25(OH)D in week 30 of gestation and offspring cardio-metabolic risk factors. However, the analyses did suggest a possible inverse association with blood pressure in females.

Conclusions

No clear association between maternal 25(OH)D concentration in week 30 of gestation and cardio-metabolic risk factors in the 20 year old offspring was found.

Racial disparities in cord blood vitamin D levels and its association with small-for-gestational-age infants

OBJECTIVE

To examine the relationship of race and maternal characteristics and their association with cord blood vitamin D levels and small-for-gestational-age (SGA) status.

STUDY DESIGN

Cord blood vitamin D levels were measured in 438 infants (276 black and 162 white). Multivariable logistic regression models were used to evaluate associations between maternal characteristics, vitamin D status and SGA.

RESULTS

Black race, Medicaid status, mean body mass index at delivery and lack of prenatal vitamin use were associated with vitamin D deficiency. Black infants had 3.6 greater adjusted odds (95% confidence interval (CI): 2.4, 5.6) of vitamin D deficiency when compared with white infants. Black infants with vitamin D deficiency had 2.4 greater adjusted odds (95% CI: 1.0, 5.8) of SGA. Vitamin D deficiency was not significantly associated with SGA in white infants.

CONCLUSION

Identification of risk factors (black race, Medicaid status, obesity and lack of prenatal vitamin use) can lead to opportunities for targeted prenatal vitamin supplementation to reduce the risk of neonatal vitamin D deficiency and SGA status.

The Effect of Omega-3 Docosahexaenoic Acid Supplementation on Gestational Length: Randomized Trial of Supplementation Compared to Nutrition Education for Increasing n-3 Intake from Foods

OBJECTIVE

DHA supplementation was compared to nutrition education to increase DHA consumption from fish and DHA fortified foods.

DESIGN

This two-part intervention included a randomized double-blind placebo controlled DHA supplementation arm and a nutrition education arm designed to increase intake of DHA from dietary sources by 300 mg per day.

SETTING

Denver Health Hospitals and Clinics, Denver, Colorado, USA.

POPULATION

871 pregnant women aged 18-40 were recruited between 16 and 20 weeks of gestation of whom 564 completed the study and complete delivery data was available in 505 women and infants.

METHODS

Subjects received either 300 or 600 mg DHA or olive oil placebo or nutrition education.

MAIN OUTCOME VARIABLE

Gestational length.

RESULTS

Gestational length was significantly increased by 4.0-4.5 days in women supplemented with 600 mg DHA per day or provided with nutrition education. Each 1% increase in RBC DHA at delivery was associated with a 1.6-day increase in gestational length. No significant effects on birth weight, birth length, or head circumference were demonstrated. The rate of early preterm birth (1.7%) in those supplemented with DHA (combined 300 and 600 mg/day) was significantly lower than in controls.

CONCLUSION

Nutrition education or supplementation with DHA can be effective in increasing gestational length.

A review of the literature regarding nutritional supplements and their effect on vaginal flora and preterm birth

PURPOSE OF REVIEW

The aim of this review was to evaluate recently published review articles which examine the use of nutritional supplements to prevent preterm birth (PTB) by modifying vaginal bacteria.

RECENT FINDINGS

Probiotics, vitamin D and vitamin C were all identified as nutritional supplements that have the potential to alter bacterial flora and consequently reduce PTB and treat or prevent genital infections. Evidence shows that probiotics may reduce the incidence of PTB as well as being effective at treating bacterial vaginosis, a known cause for PTB. Low vitamin D levels may be associated with bacterial vaginosis, although no evidence was identified which demonstrated that vitamin D supplementation reduced the risk of having bacterial vaginosis or PTB.There is little evidence regarding vitamin C supplementation, although it does suggest a possible benefit with regard to preterm rupture of membranes; however, this did not appear to reduce rates of PTB.

SUMMARY

Although there is evidence that taking probiotics in pregnancy may reduce the incidence of PTB, it is mainly derived from small, poor quality studies. Vitamin D and vitamin C may have potential benefits, but these remain to be proven. Large randomized controlled trials are needed to more accurately evaluate the potential benefits of these low-cost interventions for reducing PTB and its consequences.

The Association of Vitamin D Status with Acute Respiratory Morbidity in Preterm Infants

OBJECTIVE

To assess the association between serum 25-hydroxyvitamin D (25OHD) levels and outcomes in preterm infants (<32 weeks gestation).

STUDY DESIGN

Serum 25OHD was measured in mothers and their infants within 24 hours of birth, before the start of enteral vitamin D supplementation, and at discharge from the neonatal intensive care unit. We evaluated the associations between vitamin D status and various early preterm outcomes.

RESULTS

Ninety-four preterm infants and their mothers were included; 92% of the infants had a 25OHD level≤50 nmol/L (20 ng/mL), and 64% had a 25OHD level<30 nmol/L (12 ng/mL). A low 25OHD level (<30 nmol/L) in preterm infants at birth was associated with increased oxygen requirement (P=.008), increased duration of intermittent positive-pressure ventilation during resuscitation at delivery (P=.032), and greater need for assisted ventilation (P=.013).

CONCLUSION

We observed a high prevalence of low 25OHD (<30 nmol/L), and found an association between vitamin D status and acute respiratory morbidity in preterm infants after birth.

Prenatal exposure to vitamin-D from fortified margarine and milk and body size at age 7 years

BACKGROUND/OBJECTIVES

Prenatal vitamin-D deficiency may be associated with increased risk of obesity later in life. Using two national vitamin-D fortification programs as the setting for a societal experiment, we investigated whether exposure to vitamin-D from fortified margarine and low-fat milk during foetal life was associated with body size at 7 years of age.

SUBJECTS/METHODS

Vitamin-D fortification of margarine was mandatory in Denmark from 1961 to 1985, and voluntary fortification of low-fat milk was permitted from 1972 to 1976. Using information on body mass index (BMI) Z-score at the age of 7 years of 54,270 children, who were measured during the mandatory Copenhagen School Health examination, we compared children according to whether the mothers were pregnant during the fortification programs or not. The comparisons were performed for children born just before and after initiation or termination of margarine and milk fortification periods, respectively. In total four sets of analyses were performed.

RESULTS

We observed no difference in mean BMI Z-score between children exposed to vitamin-D fortification in utero and non-exposed children. Similar results were observed for overweight and obesity.

CONCLUSIONS

Prenatal exposure to vitamin-D from fortification of margarine and low-fat milk showed no association with body size at 7 years.

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

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