Vitamin D status in preterm neonates and the effects of its supplementation on respiratory distress syndrome

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

KEY POINTS

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

Diagnosis and management of mineral and bone disorders in infants with CKD: clinical practice points from the ESPN CKD-MBD and Dialysis working groups and the Pediatric Renal Nutrition Taskforce

BACKGROUND

Infants with chronic kidney disease (CKD) form a vulnerable population who are highly prone to mineral and bone disorders (MBD) including biochemical abnormalities, growth retardation, bone deformities, and fractures. We present a position paper on the diagnosis and management of CKD-MBD in infants based on available evidence and the opinion of experts from the European Society for Paediatric Nephrology (ESPN) CKD-MBD and Dialysis working groups and the Pediatric Renal Nutrition Taskforce.

METHODS

PICO (Patient, Intervention, Comparator, Outcomes) questions were generated, and relevant literature searches performed covering a population of infants below 2 years of age with CKD stages 2-5 or on dialysis. Clinical practice points (CPPs) were developed and leveled using the American Academy of Pediatrics grading matrix. A Delphi consensus approach was followed.

RESULTS

We present 34 CPPs for diagnosis and management of CKD-MBD in infants, including dietary control of calcium and phosphate, and medications to prevent and treat CKD-MBD (native and active vitamin D, calcium supplementation, phosphate binders).

CONCLUSION

As there are few high-quality studies in this field, the strength of most statements is weak to moderate, and may need to be adapted to individual patient needs by the treating physician. Research recommendations to study key outcome measures in this unique population are suggested. A higher resolution version of the Graphical abstract is available as Supplementary information.

Vitamin D supplementation improved physical growth and neurologic development of Preterm Infants receiving Nesting Care in the neonatal Intensive Care Unit

OBJECTIVE

To study the effects of vitamin D supplementation on physical growth and neurologic development of very preterm infants receiving nesting intervention in the neonatal intensive care unit (NICU).

METHODS

A total of 196 preterm infants had been hospitalized in NICU with the gestational age (GA) between 28 and 32 weeks. Among them, 98 preterm infants received nesting intervention, and the other 98 cases received both nesting and vitamin D supplementation (400 IU). The interventions were continued until 36 weeks postmenstrual age (PMA). The 25(OH)D serum levels, anthropometric parameters, and Premie-Neuro (PN) scores were compared at 36 weeks PMA.

RESULTS

Higher median serum level of 25(OH)D was found in the nesting + vitamin D [38.40 ng/mL (IQR: 17.20 ~ 70.88) ng/mL] as compared to the nesting group [15.95 ng/mL (IQR: 10.80 ~ 24.30) ng/mL] at 36 weeks PMA. Besides, infants receiving combined nesting intervention and vitamin D supplementation had less proportion of vitamin D deficiency [VDD, 25(OH)D levels < 20 ng/mL] than those receiving nesting intervention alone. After intervention, the anthropometric parameters of infants, including weight, length, BMI and head circumference were improved in the nesting + vitamin D group as compared to the nesting group at 36 weeks PMA, with higher scores of neurological, movement and responsiveness.

CONCLUSIONS

Vitamin D supplementation effectively decreased the prevalence of VDD and led to higher concentrations of 25(OH)D at 36 weeks PMA. This was one more study that supported the necessity of vitamin D supplementation to improve physical growth and neurologic development of preterm-born newborns who received nesting intervention in the NICU.

The Impact of Maternal Probiotics on Intestinal Vitamin D Receptor Expression in Early Life

Vitamin D signaling via the Vitamin D Receptor (VDR) has been shown to protect against intestinal inflammation. Previous studies have also reported the mutual interactions of intestinal VDR and the microbiome, indicating a potential role of probiotics in modulating VDR expression. In preterm infants, although probiotics have been shown to reduce the incidence of necrotizing enterocolitis (NEC), they are not currently recommended by the FDA due to potential risks in this population. No previous studies have delved into the effect of maternally administered probiotics on intestinal VDR expression in early life. Using an infancy mouse model, we found that young mice exposed to maternally administered probiotics (SPF/LB) maintained higher colonic VDR expression than our unexposed mice (SPF) in the face of a systemic inflammatory stimulus. These findings indicate a potential role for microbiome-modulating therapies in preventing diseases such as NEC through the enhancement of VDR signaling.

A Modern Look at the Development of Intrauterine Pneumonia in Premature Newborns: Literature Review

Infectious diseases such as malaria, pneumonia, diarrhea and preventable neonatal diseases are common causes of death in children. Globally, neonatal mortality is 44% (2.9 million) annually, with up to 50% of babies dying within the first day of life. Pneumonia kills between 750000 and 1.2 million infants in the neonatal period each year in developing countries. Premature birth, pneumonia, and labor complications are common causes of neonatal mortality. The objective of the study is to present the general characteristics of congenital pneumonia, vitamin D deficiency and micronutrient deficiencies in premature infants. To date, numerous studies confirm the relationship between the inadequate supply of the body with macro- and microelements and the development of diseases of varying severity, including metabolic disorders. Based on this, primary screening, aimed at identifying metabolic disorders of macro- and microelements and further drug correction, should become the main concept for the management of patients in modern times.

The association of serum vitamin D level and neonatal respiratory distress syndrome

BACKGROUND

Neonatal respiratory distress syndrome (NRDS) is a critical disease in premature infants. Vitamin D plays an important role in promoting the development of fetal lung structure and the formation of pulmonary surfactants. This study aimed to investigate the correlation between the serum 25(OH)D₃ level in the cord blood of premature infants and the prognosis of NRDS.

METHODS

This retrospective study recruited 82 preterm infants (gestational age 28-36 weeks) diagnosed with NRDS as the NRDS group, and 82 non-NRDS preterm infants as the control group, respectively. The diagnostic efficiency of 25(OH)D₃ on NRDS was revealed by receiver operating characteristics curve (ROC) analysis. Enzyme linked immunosorbent assay (ELISA) was performed to evaluate the 25(OH)D₃ level in the serum of the cord blood in preterm neonates. The NRDS risk indicators were identified by the multivariate logistic regression analysis.

RESULTS

Cord blood 25(OH)D₃ levels were significantly lower in NRDS preterm infants than control group infants. 25(OH)D₃ levels in cord blood can be used to predict NRDS in preterm infants. In addition, 25(OH)D₃ levels in cord blood were positively correlated with Apgar score (1 min/5 min) and negatively correlated with oxygen support/CPAP duration in preterm infants with NRDS. 25(OH)D₃ in cord blood <57.69 nmol/L (24 ng/ml), gestational age <31 weeks, birth weight <1.86 kg, Apgar score (1 min) <7 and Apgar score (5 min) < 8 were independent risk factors for NRDS.

CONCLUSION

25(OH)D₃ level is an independent risk factor for NRDS in preterm infants.

Association between vitamin D level and respiratory distress syndrome: A systematic review and meta-analysis

BACKGROUND

Growing evidence suggests an association between the vitamin D levels and respiratory outcomes of preterm infants. The objective of this systematic review and meta-analysis was to explore whether premature neonates with a vitamin D deficiency have an increased risk of respiratory distress syndrome (RDS).

METHODS

We searched PubMed, EMBASE, and the Cochrane Library up through July 20, 2021. The search terms were 'premature infant', 'vitamin D', and 'respiratory distress syndrome'. We retrieved randomized controlled trials and cohort and case-control studies. For statistical analysis, we employed the random-effects model in Comprehensive Meta-Analysis Software ver. 3.3. We employed the Newcastle-Ottawa Scales for quality assessment of the included studies.

RESULTS

A total of 121 potentially relevant studies were found, of which 15 (12 cohort studies and 3 case-control studies) met the inclusion criteria; the studies included 2,051 preterm infants. We found significant associations between RDS development in such infants and vitamin D deficiency within 24 h of birth based on various criteria, thus vitamin D levels < 30 ng/mL (OR 3.478; 95% CI 1.817-6.659; p < 0.001), < 20 ng/mL (OR 4.549; 95% CI 3.007-6.881; p < 0.001), < 15 ng/mL (OR 17.267; 95% CI 1.084-275.112; p = 0.044), and < 10 ng/ml (OR 1.732; 95% CI 1.031-2.910; p = 0.038), and an even lower level of vitamin D (SMD = -0.656; 95% CI -1.029 to -0.283; p = 0.001).

CONCLUSION

Although the vitamin D deficiency definitions varied and different methods were used to measure vitamin D levels, vitamin D deficiency or lower levels of vitamin D within 24 h of birth were always associated with RDS development. Monitoring of neonatal vitamin D levels or the maintenance of adequate levels may reduce the risk of RDS.

Role of soluble triggering receptors expressed on myeloid cells-1 and 25-hydroxy vitamin D as early diagnostic markers of neonatal Ventilator-associated pneumonia: A prospective cohort study

BACKGROUND

Ventilator-associated pneumonia (VAP) is one of the most common causes of nosocomial pneumonia in ventilated neonates. Nevertheless, its diagnosis is challenging due to the nonspecific clinical parameters and the lack of sensitive biomarkers. The main objective of this study was to compare soluble triggering receptors expressed on myeloid cells-1 (sTREM-1) and 25-hydroxy vitamin D as early predictors of neonatal VAP.

METHODS

This prospective cohort study included 85 ventilated neonates divided into the VAP group (n = 33) and the non-VAP group (n = 52). sTREM-1 levels in the endotracheal aspirate (ETA) and serum 25-hydroxy vitamin D levels were measured on the third and seventh days following mechanical ventilation. The Ethical and Research Committee approved the study at Tanta University Hospitals, Egypt (with the Approval code: 32751/12/18).

RESULTS

The sTREM-1 cutoff value of >0.46 and >0.44 ng/ml at 3 and 7 days had a sensitivity of 93.94% and 96.97%, a specificity of 92.31% and 100%, and an area under the receiver operating characteristic curve (AUC) of 0.963 and 0.993, respectively, to predict the development of neonatal VAP. A serum 25-hydroxy vitamin D cutoff value of ≤17.5 ng/ml at 3 and 7 days had a sensitivity of 90.91% and 81.82%, a specificity of 75% and 78.85%, and area under the curve of 0.877 and 0.939, respectively.

CONCLUSION

Both sTREM-1 in ETA and serum 25-hydroxy vitamin D could be used as early predictors of neonatal VAP, but sTREM-1 appears more useful.

COVID-19 disease and autoimmune disorders: A mutual pathway

Coronavirus disease 2019 (COVID-19) is a real challenge for humanity with high morbidity and mortality. Despite being primarily a respiratory illness, COVID-19 can affect nearly every human body tissue, causing many diseases. After viral infection, the immune system can recognize the viral antigens presented by the immune cells. This immune response is usually controlled and terminated once the infection is aborted. Nevertheless, in some patients, the immune reaction becomes out of control with the development of autoimmune diseases. Several human tissue antigens showed a strong response with antibodies directed against many severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins, such as SARS-CoV-2 S, N, and autoimmune target proteins. The immunogenic effects of SARS-CoV-2 are due to the sizeable viral RNA molecules with interrupted transcription increasing the pool of epitopes with increased chances of molecular mimicry and interaction with the host immune system, the overlap between some viral and human peptides, the viral induced-tissue damage, and the robust and complex binding between sACE-2 and SARS-CoV-2 S protein. Consequently, COVID-19 and its vaccine may trigger the development of many autoimmune diseases in a predisposed patient. This review discusses the mutual relation between COVID-19 and autoimmune diseases, their interactive effects on each other, the role of the COVID-19 vaccine in triggering autoimmune diseases, the factors affecting the severity of COVID-19 in patients suffering from autoimmune diseases, and the different ways to minimize the risk of COVID-19 in patients with autoimmune diseases.

Vitamin D and calcium intakes in general pediatric populations: A French expert consensus paper

OBJECTIVES

Nutritional vitamin D supplements are often used in general pediatrics. Here, the aim is to address vitamin D supplementation and calcium nutritional intakes in newborns, infants, children, and adolescents to prevent vitamin D deficiency and rickets in general populations.

STUDY DESIGN

We formulated clinical questions relating to the following categories: the Patient (or Population) to whom the recommendation will apply; the Intervention being considered; the Comparison (which may be "no action," placebo, or an alternative intervention); and the Outcomes affected by the intervention (PICO). These PICO elements were arranged into the questions to be addressed in the literature searches. Each PICO question then formed the basis for a statement. The population covered consisted of children aged between 0 and 18 years and premature babies hospitalized in neonatology. Two groups were assembled: a core working group and a voting panel from different scientific pediatric committees from the French Society of Pediatrics and national scientific societies.

RESULTS

We present here 35 clinical practice points (CPPs) for the use of native vitamin D therapy (ergocalciferol, vitamin D2 and cholecalciferol, vitamin D3) and calcium nutritional intakes in general pediatric populations.

CONCLUSION

This consensus document was developed to provide guidance to health care professionals on the use of nutritional vitamin D and dietary modalities to achieve the recommended calcium intakes in general pediatric populations. These CPPs will be revised periodically. Research recommendations to study key vitamin D outcome measures in children are also suggested.

Maternal Vitamin D Status Correlates to Leukocyte Antigenic Responses in Breastfeeding Infants

It is unknown if vitamin D (vitD) sufficiency in breastfeeding mothers can lead to physiological outcomes for their children that are discernible from infant vitD sufficiency per se. In a 3-month, randomized vitD supplementation study of mothers and their exclusively breastfeeding infants, the effects of maternal vitD sufficiency were determined on infant plasma concentrations of 25-hydroxyvitamin D (i.e., vitD status) and 11 cytokines. An inverse correlation was seen between maternal vitD status and infant plasma TNF concentration (r = −0.27; p < 0.05). Infant whole blood was also subjected to in vitro antigenic stimulation. TNF, IFNγ, IL-4, IL-13, and TGFβ1 responses by infant leukocytes were significantly higher if mothers were vitD sufficient but were not as closely correlated to infants’ own vitD status. Conversely, IL-10 and IL-12 responses after antigenic challenge were more correlated to infant vitD status. These data are consistent with vitD-mediated changes in breast milk composition providing immunological signaling to breastfeeding infants and indicate differential physiological effects of direct-infant versus maternal vitD supplementation. Thus, consistent with many previous studies that focused on the importance of vitD sufficiency during pregnancy, maintenance of maternal sufficiency likely continues to affect the health of breastfed infants.

Aging of the Immune System: Focus on Natural Killer Cells Phenotype and Functions

Aging is the greatest risk factor for nearly all major chronic diseases, including cardiovascular diseases, cancer, Alzheimer’s and other neurodegenerative diseases of aging. Age-related impairment of immune function (immunosenescence) is one important cause of age-related morbidity and mortality, which may extend beyond its role in infectious disease. One aspect of immunosenescence that has received less attention is age-related natural killer (NK) cell dysfunction, characterized by reduced cytokine secretion and decreased target cell cytotoxicity, accompanied by and despite an increase in NK cell numbers with age. Moreover, recent studies have revealed that NK cells are the central actors in the immunosurveillance of senescent cells, whose age-related accumulation is itself a probable contributor to the chronic sterile low-grade inflammation developed with aging (“inflammaging”). NK cell dysfunction is therefore implicated in the increasing burden of infection, malignancy, inflammatory disorders, and senescent cells with age. This review will focus on recent advances and open questions in understanding the interplay between systemic inflammation, senescence burden, and NK cell dysfunction in the context of aging. Understanding the factors driving and enforcing NK cell aging may potentially lead to therapies countering age-related diseases and underlying drivers of the biological aging process itself.

Current Overview on Therapeutic Potential of Vitamin D in Inflammatory Lung Diseases

Inflammatory lung disorders (ILDs) are one of the world's major reasons for fatalities and sickness, impacting millions of individuals of all ages and constituting a severe and pervasive health hazard. Asthma, lung cancer, bronchiectasis, pulmonary fibrosis acute respiratory distress syndrome, and COPD all include inflammation as a significant component. Microbe invasions, as well as the damage and even death of host cells, can cause and sustain inflammation. To counteract the negative consequences of irritants, the airways are equipped with cellular and host defense immunological systems that block the cellular entrance of these irritants or eliminate them from airway regions by triggering the immune system. Failure to activate the host defense system will trigger chronic inflammatory cataracts, leading to permanent lung damage. This damage makes the lungs more susceptible to various respiratory diseases. There are certain restrictions of the available therapy for lung illnesses. Vitamins are nutritional molecules that are required for optimal health but are not produced by the human body. Cholecalciferol (Vitamin D) is classified as a vitamin, although it is a hormone. Vitamin D is thought to perform a function in bone and calcium homeostasis. Recent research has found that vitamin D can perform a variety of cellular processes, including cellular proliferation; differentiation; wound repair; healing; and regulatory systems, such as the immune response, immunological, and inflammation. The actions of vitamin D on inflammatory cells are dissected in this review, as well as their clinical significance in respiratory illnesses.

Vitamin D Status and Factors Associated with Vitamin D Deficiency during the First Year of Life in Preterm Infants

We aimed to investigate the changes in vitamin D levels and factors associated with vitamin D deficiency (VDD) during the first year of life in Korean preterm infants. We enrolled 333 preterm infants who were born at Kyungpook National University Children’s Hospital between March 2013 and December 2019. 25-hydroxyvitamin D (25-OHD) levels and medical records were collected at birth, 6 months, and 12 months of age. The mean gestational age was 33.4 ± 2.3 weeks and mean 25-OHD levels at birth were 18.2 ± 13.5 ng/mL. The incidence of VDD was 82.8%, 30.6%, and 27.0% at birth, 6 months, and 12 months, respectively. The incidence of severe VDD (25-OHD < 10 ng/mL) was 31.5%, 1.5%, and 0%, at birth, 6 months, and 12 months, respectively. Among infants with severe VDD, the deficiency persisted in 49.6% at 6 months, and 35.3% at 12 months. The strongest predictor of VDD during follow-up was 25-OHD concentration at birth. Vitamin D supplementation at 400 IU/day did not affect vitamin D levels during the first year of life. Therefore, it is important to prevent neonatal VDD through maternal vitamin D supplementation during pregnancy. Further research is needed to determine the optimal vitamin D supplementation dose for Korean preterm infants.

The burden of hyaline membrane disease, mortality and its determinant factors among preterm neonates admitted at Debre Tabor General Hospital, North Central Ethiopia: A retrospective follow up study

BACKGROUND

Hyaline membrane disease (HMD) is a leading cause of morbidity and mortality in preterm newborn babies. Though, there are studies related to Hyaline membrane disease inclusive of all neonates, studies related to the burden among preterm neonates were limited. In addition, increasing neonatal mortality in Ethiopia could be related to increase in the burden of hyaline membrane disease among preterm neonates. Therefore, this study was aimed to assess the burden of hyaline membrane disease, mortality and its associated factors among preterm neonate admitted at neonatal intensive care unit, North Central Ethiopia.

METHODOLOGY

An institution-based retrospective follow-up study was conducted among 535 preterm neonates admitted at neonatal intensive care unit from January 1, 2014-December 30, 2017. Data were entered into EPi-data 4.2.0.0 and transferred to STATA version 14 statistical software for statistical analysis. Binary logistic regression was used for the analysis. All variables with P-value < 0.25 during bi-variable analysis were considered for multivariable logistic regression. Level of statistical significance was declared at P value ≤0.05.

RESULTS

In the current study, proportion of hyaline membrane disease was 40% (95% CI; 35.8, 44.3) of which 49.5% died. Preterm neonate born with Gestational age of less than 34 weeks of age (Adjusted odd ratio (AOR = 2.64; 95 CI: 1.49, 4.66)), 5th minute Apgar score less than 7 (AOR = 2.2; 95% CI: 1.20, 4.07), and newborn with birth weight of less than 1500 gram (AOR = 2.4, 95% CI: 1.3, 4.3) were predictors of hyaline membrane disease.

CONCLUSIONS

The mean gestational age (±) was 33.46 (±2.55) weeks. The incidence of hyaline membrane disease among preterm admissions was high. Preterm neonate born with gestational age of less than 34 weeks of age, asphyxiated newborns and newborn with birth weight of less than 1500 gram were predictors of hyaline membrane disease. So, emphasis should be given on early screening, follow up and timely interventions for preterm neonate.

Vitamin D improves pulmonary function in a rat model for congenital diaphragmatic hernia

A congenital diaphragmatic hernia (CDH) is an anomaly caused by defects in the diaphragm; the resulting limited thorax cavity in turn restricts lung growth (pulmonary hypoplasia). This condition is related to pulmonary hypertension. Despite advances in neonatal CDH therapy, the mortality for severe pulmonary hypoplasia remains high. Therefore, it is essential to establish prenatal therapeutic interventions. Vitamin D was reported to have beneficial effects on adult pulmonary hypertension. This study aims to evaluate the efficacy of prenatal vitamin D administration for CDH. First, serum 25-hydroxyvitamin D [25(OH)D] levels in umbilical cord blood were evaluated among CDH newborns. Second, Sprague Dawley rat CDH models were exposed to nitrofen on embryo day 9 (E9). Randomly selected rats in the nitrofen-treated group were infused with calcitriol from E9 to E21. Samples from CDH pups diagnosed after birth were used for lung weight measurements, blood gas analysis, and immunohistochemical analysis. Third, microarray analysis was performed to examine the effect of vitamin D on gene expression profiles in CDH pulmonary arterial tissues. Serum 25(OH)D levels in the umbilical cord blood of newborns who did not survive were significantly lower than those who were successfully discharged. Prenatal vitamin D showed no significant effect on CDH incidence or lung weight but attenuated alveolarization and pulmonary artery remodeling accompanied the improved blood gas parameters. Vitamin D inhibited several gene expression pathways in the pulmonary arteries of CDH rats. Our results suggest that prenatal vitamin D administration attenuates pulmonary vascular remodeling by influencing several gene pathways in CDH.

Association Between Vitamin D Level and Neonatal Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

In recent years, vitamin D in the occurrence of lung diseases has gradually become a hot topic. Although the role of vitamin D in normal lung development has been confirmed, the correlation between vitamin D level and neonatal respiratory distress syndrome (NRDS) is not clear.

OBJECTIVE

To evaluate the association between vitamin D level and NRDS.

METHODS

We performed a comprehensive search of the following electronic databases: PubMed, Embase, Cochrane Library, Web of Science, and China National Knowledge Infrastructure (CNKI). Literature screening and quality assessment were performed according to inclusion and exclusion criteria. The Newcastle-Ottawa Scale was used to assess the methodological components of each study, and Stata 15.1 software to perform the Meta-analysis.

RESULTS

A total of nine case-control studies were included, with 653 infants with NRDS and 501 infants without NRDS. The Meta-analysis showed no heterogeneity across all studies(I²=0.0%, P=0.583). The fixed-effect model showed that 25 hydroxy vitamin D level of children in the NRDS group was significantly lower than that of the non-NRDS group(SMD = -0.51, 95%CI: -0.63 to -0.39, p ≤ 0.05).

CONCLUSION

This systematic review and meta-analysis study suggests that vitamin D deficiency is very likely to be a high-risk factor of NRDS, and reasonable vitamin D supplementation during pregnancy and after birth is of great significance.

Low Vitamin D Levels at Birth and Early Respiratory Outcome in Infants With Gestational Age Less Than 29 Weeks

BACKGROUND

Vitamin D (VitD) is involved in lung development but its influence on respiratory distress syndrome of extremely preterm (EPT) infants have been little investigated. In this study, we examined the influence of low vitamin D status at birth on early respiratory outcomes of this vulnerable infant population.

METHODS

Cord blood 25(OH)D levels ≤ 75 nmol/L were considered as Low vitamin D levels. Stepwise logistic regression and classification regression-tree analyses were used and the primary outcome was the combined outcome of death or mechanical ventilation need by the end of the first week (death or MV DoL7) as a marker od RDS severity.

RESULTS

The mean (SD) GA and birth weight were 26 (1.4) weeks and 801 (212) gr, respectively; 81/109 (74%) infants had low 25(OH)D levels. Infants with low VitD levels had 25% higher initial FiO₂ levels (p < 0.05) and were more likely to be mechanically ventilated on DoL7 (36 vs. 7%, p < 0.05). Adjusted for gestational age, they had 10-fold higher odds of death or MV DoL7 (p < 0.01). By regression tree analysis, the rate of death or MV DoL7 increased from 18 to 71% in infants with GA < 26 weeks and with cord blood 25(OH)D levels higher and lower than 74 nmol/L, respectively (p < 0.05).

CONCLUSION

Low vitamin D levels at birth are associated with early adverse respiratory outcomes in infants with GA less 29 weeks. Further largest studies are needed to confirm this association.

Vitamin D supplementation for term breastfed infants to prevent vitamin D deficiency and improve bone health

BACKGROUND

Vitamin D deficiency is common worldwide, contributing to nutritional rickets and osteomalacia which have a major impact on health, growth, and development of infants, children and adolescents. Vitamin D levels are low in breast milk and exclusively breastfed infants are at risk of vitamin D insufficiency or deficiency.

OBJECTIVES

To determine the effect of vitamin D supplementation given to infants, or lactating mothers, on vitamin D deficiency, bone density and growth in healthy term breastfed infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to 29 May 2020 supplemented by searches of clinical trials databases, conference proceedings, and citations.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs in breastfeeding mother-infant pairs comparing vitamin D supplementation given to infants or lactating mothers compared to placebo or no intervention, or sunlight, or that compare vitamin D supplementation of infants to supplementation of mothers.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial eligibility and risk of bias and independently extracted data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 19 studies with 2837 mother-infant pairs assessing vitamin D given to infants (nine studies), to lactating mothers (eight studies), and to infants versus lactating mothers (six studies). No studies compared vitamin D given to infants versus periods of infant sun exposure. Vitamin D supplementation given to infants: vitamin D at 400 IU/day may increase 25-OH vitamin D levels (MD 22.63 nmol/L, 95% CI 17.05 to 28.21; participants = 334; studies = 6; low-certainty) and may reduce the incidence of vitamin D insufficiency (25-OH vitamin D < 50 nmol/L) (RR 0.57, 95% CI 0.41 to 0.80; participants = 274; studies = 4; low-certainty). However, there was insufficient evidence to determine if vitamin D given to the infant reduces the risk of vitamin D deficiency (25-OH vitamin D < 30 nmol/L) up till six months of age (RR 0.41, 95% CI 0.16 to 1.05; participants = 122; studies = 2), affects bone mineral content (BMC), or the incidence of biochemical or radiological rickets (all very-low certainty). We are uncertain about adverse effects including hypercalcaemia. There were no studies of higher doses of infant vitamin D (> 400 IU/day) compared to placebo. Vitamin D supplementation given to lactating mothers: vitamin D supplementation given to lactating mothers may increase infant 25-OH vitamin D levels (MD 24.60 nmol/L, 95% CI 21.59 to 27.60; participants = 597; studies = 7; low-certainty), may reduce the incidences of vitamin D insufficiency (RR 0.47, 95% CI 0.39 to 0.57; participants = 512; studies = 5; low-certainty), vitamin D deficiency (RR 0.15, 95% CI 0.09 to 0.24; participants = 512; studies = 5; low-certainty) and biochemical rickets (RR 0.06, 95% CI 0.01 to 0.44; participants = 229; studies = 2; low-certainty). The two studies that reported biochemical rickets used maternal dosages of oral D3 60,000 IU/day for 10 days and oral D3 60,000 IU postpartum and at 6, 10, and 14 weeks. However, infant BMC was not reported and there was insufficient evidence to determine if maternal supplementation has an effect on radiological rickets (RR 0.76, 95% CI 0.18 to 3.31; participants = 536; studies = 3; very low-certainty). All studies of maternal supplementation enrolled populations at high risk of vitamin D deficiency. We are uncertain of the effects of maternal supplementation on infant growth and adverse effects including hypercalcaemia. Vitamin D supplementation given to infants compared with supplementation given to lactating mothers: infant vitamin D supplementation compared to lactating mother supplementation may increase infant 25-OH vitamin D levels (MD 14.35 nmol/L, 95% CI 9.64 to 19.06; participants = 269; studies = 4; low-certainty). Infant vitamin D supplementation may reduce the incidence of vitamin D insufficiency (RR 0.61, 95% CI 0.40 to 0.94; participants = 334; studies = 4) and may reduce vitamin D deficiency (RR 0.35, 95% CI 0.17 to 0.72; participants = 334; studies = 4) but the evidence is very uncertain. Infant BMC and radiological rickets were not reported and there was insufficient evidence to determine if maternal supplementation has an effect on infant biochemical rickets. All studies enrolled patient populations at high risk of vitamin D deficiency. Studies compared an infant dose of vitamin D 400 IU/day with varying maternal vitamin D doses from 400 IU/day to > 4000 IU/day. We are uncertain about adverse effects including hypercalcaemia.

AUTHORS' CONCLUSIONS

For breastfed infants, vitamin D supplementation 400 IU/day for up to six months increases 25-OH vitamin D levels and reduces vitamin D insufficiency, but there was insufficient evidence to assess its effect on vitamin D deficiency and bone health. For higher-risk infants who are breastfeeding, maternal vitamin D supplementation reduces vitamin D insufficiency and vitamin D deficiency, but there was insufficient evidence to determine an effect on bone health. In populations at higher risk of vitamin D deficiency, vitamin D supplementation of infants led to greater increases in infant 25-OH vitamin D levels, reductions in vitamin D insufficiency and vitamin D deficiency compared to supplementation of lactating mothers. However, the evidence is very uncertain for markers of bone health. Maternal higher dose supplementation (≥ 4000 IU/day) produced similar infant 25-OH vitamin D levels as infant supplementation of 400 IU/day. The certainty of evidence was graded as low to very low for all outcomes.