A Comparison of 3 Vitamin D Dosing Regimens in Extremely Preterm Infants: A Randomized Controlled Trial

Risk factors and outcomes of vitamin D deficiency in very preterm infants

BACKGROUND

Vitamin D is essential for bone health and immune system. Vitamin D deficiency (VDD) poses a high-risk to very preterm (VP) infants. This study aimed to evaluate the risk factors associated with VDD in VP infants and its potential clinical outcomes.

METHODS

A retrospective cohort study was conducted on VP infants admitted to the neonatal intensive care unit of a specialized tertiary hospital in Seoul, Republic of Korea, between January 2018 and June 2022. Serum 25-hydroxyvitamin D (25(OH)D) levels and other biochemical parameters were measured between 4 and 6 weeks of age. VDD was defined as a serum 25(OH)D level <20 ng/mL. Prenatal and postnatal risk factors and clinical outcomes were compared between the VDD and non-VDD groups.

RESULTS

Of the 82 VP infants analyzed, 27 (32.9%) were diagnosed with VDD. The VDD group exhibited a significantly longer duration of parenteral nutrition (PN) compared to the non-VDD group (adjusted odds ratio [OR] = 1.12; 95% confidence interval [CI]: 1.008-1.245). Breast milk intake was lower in the VDD group than in the non-VDD group (adjusted OR = 0.976, 95% CI, 0.955-0.999). Notably, calcium levels were significantly lower in the VDD group, while parathyroid hormone levels were significantly higher, compared with the non-VDD group. Additionally, the rickets severity score was higher in the VDD group than in the non-VDD, although the difference was not statistically significant.

CONCLUSIONS

Prolonged PN duration and low breast milk intake significantly increased the risk of VDD in VP infants.

Oxygen in the neonatal ICU: a complicated history and where are we now?

Despite major advances in neonatal care, oxygen remains the most commonly used medication in the neonatal intensive care unit (NICU). Supplemental oxygen can be life-saving for term and preterm neonates in the resuscitation period and beyond, however use of oxygen in the neonatal period must be judicious as there can be toxic effects. Newborns experience substantial hemodynamic changes at birth, rapid energy consumption, and decreased antioxidant capacity, which requires a delicate balance of sufficient oxygen while mitigating reactive oxygen species causing oxidative stress. In this review, we will discuss the physiology of neonates in relation to hypoxia and hyperoxic injury, the history of supplemental oxygen in the delivery room and beyond, supporting clinical research guiding trends for oxygen therapy in neonatal care, current practices, and future directions.

Is 25OH Vitamin D Excess before 36 Weeks Corrected Age an Independent Risk Factor for Bronchopulmonary Dysplasia or Death?

Low 25-Hydroxyvitamin D (25(OH)D) in preterm infants is a risk factor for bronchopulmonary dysplasia (BPD), but increased supplementation failed to demonstrate a beneficial effect on BPD. In neonatal animal models, deficiency and excessive vitamin D exposure have been associated with increased mortality and histological alterations in the lung evocative of BPD. Our hypothesis is that 25(OH)D levels ≥ 120 nmol/L are also a risk factor for BPD or death. This retrospective single-center cohort study included only infants born at <31 weeks gestational age without major malformations with at least a determination of 25(OH)D at <36 weeks corrected age and no determination <50 nmol/L. Routine 25(OH)D determination was performed at 1 month and monthly thereafter. A total of 175 infants were included. Infants with BPD or who died had a significantly lower term and weight, but a similar frequency of 25(OH)D ≥120 nmol/L (50.5% vs. 43.9%, p = 0.53). The logistic regression identified weight (OR 0.997, 95% CI [0.995-0.998]) and term (OR 0.737, 95% CI [0.551-0.975]) as significantly associated with BPD or death; the occurrence of excessive 25(OH)D was not significantly associated (OR 1.029, 95% CI [0.503-2.093]). The present study did not demonstrate any significant association between excessive 25(OH)D after one month of age and BPD or death.

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.

Risk factors associated with vitamin D deficiency in preterm neonates: a single-center step-wise regression analysis

BACKGROUND

Vitamin D deficiency is particularly concerning in pregnant women, leading to various health-related issues in mothers and their babies, especially those born prematurely, including neonatal skeletal and respiratory disorders. In addition, there have been several reports indicating the presence of multiple impactful factors in the development of vitamin D deficiency. Therefore, we aimed to evaluate the vitamin D level in very preterm and moderately preterm newborns and investigate its association with presumed influential factors.

METHODS

This cross-sectional descriptive study was performed on 54 mothers and their preterm neonates with gestational ages less than 34 weeks at delivery (i.e., very preterm and moderately preterm). After the serum vitamin D levels were determined from samples obtained in the first 24 h after birth, the babies were divided into two groups based on the presence or absence of deficiency. The relationship between several factors and the neonatal serum vitamin D level was investigated separately and in a linear step-wise regression model.

RESULTS

The differences between the groups regarding maternal age, gestational age, neonate's gender, birth weight, and delivery method with neonatal vitamin D levels were not statistically significant. However, maternal vitamin D levels strongly correlated with neonatal vitamin D levels (P-value < 0.001, r = 0.636). The regression model also yielded a strong predictive capability (P-value < 0.001, Adjusted R² = 0.606), with the maternal vitamin D level demonstrating a significant impact.

CONCLUSIONS

Low vitamin D levels in pregnant mothers correlate with deficient levels in their preterm neonates. Therefore, as vitamin D deficiency significantly affects both the mother's and newborn's health, it is recommended that healthcare providers provide comprehensive plans for vitamin D supplementation during pregnancy.

Enteral Nutrition in Preterm Infants (2022): A Position Paper From the ESPGHAN Committee on Nutrition and Invited Experts

OBJECTIVES

To review the current literature and develop consensus conclusions and recommendations on nutrient intakes and nutritional practice in preterm infants with birthweight <1800 g.

METHODS

The European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee of Nutrition (CoN) led a process that included CoN members and invited experts. Invited experts with specific expertise were chosen to represent as broad a geographical spread as possible. A list of topics was developed, and individual leads were assigned to topics along with other members, who reviewed the current literature. A single face-to-face meeting was held in February 2020. Provisional conclusions and recommendations were developed between 2020 and 2021, and these were voted on electronically by all members of the working group between 2021 and 2022. Where >90% consensus was not achieved, online discussion meetings were held, along with further voting until agreement was reached.

RESULTS

In general, there is a lack of strong evidence for most nutrients and topics. The summary paper is supported by additional supplementary digital content that provide a fuller explanation of the literature and relevant physiology: introduction and overview; human milk reference data; intakes of water, protein, energy, lipid, carbohydrate, electrolytes, minerals, trace elements, water soluble vitamins, and fat soluble vitamins; feeding mode including mineral enteral feeding, feed advancement, management of gastric residuals, gastric tube placement and bolus or continuous feeding; growth; breastmilk buccal colostrum, donor human milk, and risks of cytomegalovirus infection; hydrolyzed protein and osmolality; supplemental bionutrients; and use of breastmilk fortifier.

CONCLUSIONS

We provide updated ESPGHAN CoN consensus-based conclusions and recommendations on nutrient intakes and nutritional management for preterm infants.

Vitamin d deficiency with high parathyroid hormone levels is related to late onset SEPSIS among preterm infants

Preterm infants (PTs) are at greater risk for vitamin D deficiency, which relates to the possibility of a higher incidence of comorbidities. Our goal was twofold, 1) to monitor vitamin D, calcium, phosphorus, parathyroid hormone (PTH), matrix metalloproteinase-8 (MMP-8) serum levels at three-time points during hospitalization, and 2) to assess the association between 25-hydroxyvitamin D (25OHD) levels and outcomes in PTs.

METHODS

We carried out a follow-up on 50 Caucasian PTs ≤ 32 weeks of gestational age (GA) and/or ≤ 1500 g birth weight at 28 days and at 4 months. PTs were divided into two subgroups for tests of association with clinical outcomes based on vitamin D deficient infants 25(OH) D cord blood levels: ≤ 20 ng/ml). At an initial stage, 25(OH) D levels were determined in maternal/preterm blood samples and were compared to full term delivery infants.

RESULTS

There were no differences in 25(OH) D serum levels at birth when comparing PTs to term infants, or regarding maternal levels. A strong positive correlation was detected between maternal and neonatal 25(OH) D serum levels among PTs and term infants (r: 0.466; p < 0.001). Neonates with vitamin D deficiency did not present a higher incidence of comorbidities. PTs were classified in two subgroups based on vitamin D and PTH (group 1: vitamin D < 20 ng/mL and PTH > 60 pg/mL; group 2: vitamin D > 20 and PTH < 60 pg/mL). The PTs in group 1 showed a higher incidence of LOS (RR: 2; 95% CI: 1.31-3.55). No relationship was observed between MMP-8 serum levels and the incidence of sepsis.

CONCLUSIONS

This study did not find any evidence of an increase in preterm birth risk related to vitamin D level at birth. Vitamin D deficiency by itself is not associated with a higher incidence of comorbidities. However, the binomial vitamin D-PTH must be taken into consideration.

Safety and Efficacy of Early Vitamin D Supplementation in Critically Ill Extremely Preterm Infants: An Ancillary Study of a Randomized Trial

BACKGROUND

Despite substantial evidence that vitamin D deficiency is highly prevalent among infants born extremely preterm (≤28 weeks' of gestation), several consensus statements do not recommend vitamin D doses >400 IU/day for these infants. Safety remains a concern.

OBJECTIVE

The study aim was to determine safety and efficacy profiles of enteral vitamin D in Black and White infants randomized to three different vitamin D doses soon after birth.

DESIGN

Ancillary study of a masked randomized clinical trial.

PARTICIPANTS/SETTING

Seventy-three infants born extremely preterm between 2012 and 2015 at a southern US academic neonatal unit (33' latitude) who had >90% compliance with the assigned intervention were included.

INTERVENTION

Infants were randomized to receive placebo (placebo group), 200 IU/day vitamin D (200 IU group), or 800 IU/day vitamin D (800 IU group) during the first 28 days after birth.

MAIN OUTCOME MEASURES

Safety outcomes included serum 25-hydroxy vitamin D (25[OH]D) and calcium concentrations. Efficacy outcomes included the predictive risk of bronchopulmonary dysplasia.

STATISTICAL ANALYSIS

Per-protocol analysis using unadjusted, repeated-measures mixed models.

RESULTS

Mean birth weight was 815 ± 199 g. Half were male and 56% were Black. Of 58 infants with 25(OH)D measurements at birth, 40 (69%) had vitamin D deficiency (<20 ng/mL). The mean difference in 25(OH)D in nanograms per milliliter between Postnatal Day 28 and Postnatal Day 1 was +9 in the placebo group, +23 in the 200 IU group, and +62 in the 800 IU group (P < 0.0001). The increase observed in 25(OH)D was more significant among Black infants. The predictive risk of severe bronchopulmonary dysplasia in the 200 IU and 800 IU groups was lower, but this difference did not reach statistical significance. No vitamin D or calcium toxicity was observed.

CONCLUSIONS

A vitamin D dose of 800 IU/day safely corrected vitamin D deficiency by Postnatal Day 14.

Breastfeeding and vitamin D

The recent re-emergence of vitamin D deficiency (VDD) and rickets among breastfed infants without adequate sunlight exposure and vitamin D supplementation has been reported worldwide. Breastfed infants are particularly vulnerable to VDD because of the low vitamin D content of breast milk, restricted sunlight exposure, increased pollution, and limited natural dietary sources of vitamin D. The prevalence of VDD in breastfed infants differs vastly between studies and nations at 0.6%-91.1%. The recommended intake of vitamin D for lactating mothers to optimize their overall vitamin D status and, consequently, of their breast milk is 200-2,000 IU/day, indicating a lack of consensus. Some studies have suggested that maternal high-dose vitamin D supplementation (up to 6,400 IU/day) can be used as an alternate strategy to direct infant supplementation. However, concern persists about the safety of maternal high-dose vitamin D supplementation. Direct infant supplementation is the currently available option to support vitamin D status in breastfed infants. The recommended dose for vitamin D supplementation in breastfed infants according to various societies and organizations worldwide is 200-1,200 IU/day. Most international guidelines recommend that exclusively or partially breastfed infants be supplemented with 400 IU/day of vitamin D during their first year of life. However, domestic studies on the status and guidelines for vitamin D in breastfed infants are insufficient. This review summarizes the prevalence of VDD in breastfed infants, vitamin D content of breast milk, and current guidelines for vitamin D supplementation of lactating mothers and infants to prevent VDD in breastfed infants.

Enteral Vitamin D Supplementation in Preterm or Low Birth Weight Infants: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Many preterm and low birth weight (LBW) infants have low vitamin D stores. The objective of this study was to assess effects of enteral vitamin D supplementation compared with no vitamin D supplementation in human milk fed preterm or LBW infants.

METHODS

Data sources include Cochrane Central Register of Controlled Trials, Medline, and Embase from inception to March 16, 2021. The study selection included randomized trials. Data were extracted and pooled with fixed and random-effects models.

RESULTS

We found 3 trials (2479 participants) that compared vitamin D to no vitamin D. At 6 months, there was increase in weight-for-age z-scores (mean difference 0.12, 95% confidence interval [CI] 0.01 to 0.22, 1 trial, 1273 participants), height-for-age z-scores (mean difference 0.12, 95% CI 0.02 to 0.21, 1 trial, 1258 participants); at 3 months there was decrease in vitamin D deficiency (risk ratio 0.58, 95% CI 0.49 to 0.68, I2=58%, 2 trials, 504 participants) in vitamin D supplementation groups. However, there was little or no effect on mortality, any serious morbidity, hospitalization, head circumference, growth to 6 years and neurodevelopment. The certainty of evidence ranged from very low to moderate. Fourteen trials (1969 participants) assessed dose and reported no effect on mortality, morbidity, growth, or neurodevelopment, except on parathyroid hormone and vitamin D status. No studies assessed timing. Limitations include heterogeneity and small sample size in included studies.

CONCLUSIONS

Enteral vitamin D supplementation improves growth and vitamin D status in preterm and LBW infants.

Preterm Infants on Early Solid Foods and Vitamin D Status in the First Year of Life—A Secondary Outcome Analysis of a Randomized Controlled Trial

Preterm birth places infants at high risk for mineral and micronutrient deficiencies important for bone health. The aim of this study was to examine whether two timepoints for the introduction of solid foods in preterm infants have an impact on vitamin D status in the first year of life. This is a secondary outcome analysis of a prospective, randomized trial on very low birth weight (VLBW) infants, randomized to an early (10–12th week corrected age) or a late (16–18th week corrected age) complementary-feeding group. Vitamin D status was assessed by blood samples taken at 6 weeks, 6, and 12 months corrected age. In total, 177 infants were randomized (early group: n = 89, late group: n = 88). There was a tendency toward lower levels of serum 25-OH-vitamin D in the early group throughout the first year of life (p = not significant (n.s.)); no differences were detected in the other parameters. At 6 months corrected age, infants of the early group had a significantly higher incidence of vitamin D deficiency. The timepoint of the introduction of solid foods had no impact on the serum 25-OH-vitamin D levels and other parameters important for bone health but showed a tendency toward lower levels in the early-feeding group.

Nutritional Supplements to Improve Outcomes in Preterm Neonates

Preterm infants are at higher risk of mortality and morbidity compared with those born at term. Nutrition-related morbidities include poor growth, immune deficiency, nutritional deficiencies, and adverse long-term neurodevelopment. In addition to macronutrients, many nutritional supplements have been used to enhance growth and development, and decrease infections. Nutrients can enhance preterm infants' immune status, optimize the microbiome, improve growth and development, and influence the risk of necrotizing enterocolitis, sepsis, and other outcomes.

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.

Vitamin D status in very low birth weight infants and response to vitamin D intake during their NICU stays: a prospective cohort study

OBJECTIVE

To evaluate vitamin D status in very low birth weight (VLBW) infants and response to vitamin D intake.

STUDY DESIGN

In this prospective cohort study of VLBW infants, 25-hydroxyvitamin D [25(OH)D] was measured regularly starting at birth. Daily vitamin D intake was estimated from parenteral and enteral sources.

RESULTS

Of the included 83 infants born between November 2016 and March 2018, 44 (53%) had 25(OH)D < 30 ng/mL at birth but achieved vitamin D sufficiency (VDS) by 3 weeks while receiving 120-400 IU/day. Twenty-three (27.7%) infants had at least one 25(OH)D level >100 ng/mL during the study period. Infants whose intake was > 600 IU/day had higher prevalence of vitamin D excess (VDE).

CONCLUSION

In our study, low 25(OH)D was common in VLBW infants at birth. Vitamin D intake of 120-260 IU/day from parenteral and 200-400 IU/day from enteral route was appropriate for VLBW infants to achieve VDS. Doses > 600 IU/day increased risk of VDE.

Utility of umbilical cord blood 25-hydroxyvitamin D levels for predicting bronchopulmonary dysplasia in preterm infants with very low and extremely low birth weight

BACKGROUND AND OBJECTIVE

There remains controversy regarding vitamin D deficiency and bronchopulmonary dysplasia (BPD) in very low birth weight (VLBW) and extremely low birth weight (ELBW) preterm infants. This study aimed to determine the prevalence of vitamin D deficiency assessed by umbilical cord blood 25-hydroxyvitamin D [25(OH)D] in preterm infants in northeast China and to evaluate the ability and optimal threshold of 25(OH)D for predicting BPD.

METHODS

The clinical data of VLBW and ELBW preterm infants with known cord-blood 25(OH)D levels were analyzed retrospectively. Infants were divided into groups based on their cord-blood 25(OH)D levels and BPD diagnosis. Logistic regression was performed to assess the risk factors for BPD and a nomogram was established. Receiver operating characteristic (ROC) curve analysis was used to evaluate the optimal threshold of cord-blood 25(OH)D concentration for predicting BPD.

RESULTS

A total of 267 preterm infants were included, of which 225 (84.3%) exhibited vitamin D deficiency and 134 (50.2%) were diagnosed with BPD. The incidence of BPD was lower in the group with a 25(OH)D level of >20 ng/ml than in the other groups (P = 0.024). Infants with BPD had lower cord-blood 25(OH)D levels than those without BPD (11.6 vs. 13.6 ng/ml, P = 0.016). The multivariate logistic regression model revealed that 25(OH)D levels (odds ratio [OR] = 0.933, 95% confidence interval [95% CI]: 0.891-0.977), gestational age (OR = 0.561, 95% CI: 0.425-0.740), respiratory distress syndrome (OR = 2.989, 95% CI: 1.455-6.142), and pneumonia (OR = 2.546, 95% CI: 1.398-4.639) were independent risk factors for BPD. A predictive nomogram containing these four risk factors was established, which had a C-index of 0.814. ROC curve analysis revealed that the optimal cutoff value of 25(OH)D for predicting BPD was 15.7 ng/ml (area under the curve = 0.585, 95% CI: 0.523-0.645, P = 0.016), with a sensitivity of 75.4% and a specificity of 42.9%.

CONCLUSIONS

A cord-blood 25(OH)D level of <15.7 ng/ml was predictively valuable for the development of BPD. The nomogram established in this study can help pediatricians predict the risk of BPD more effectively and easily.

Supplemental Oxygen in the Newborn: Historical Perspective and Current Trends

Oxygen is the final electron acceptor in aerobic respiration, and a lack of oxygen can result in bioenergetic failure and cell death. Thus, administration of supplemental concentrations of oxygen to overcome barriers to tissue oxygen delivery (e.g., heart failure, lung disease, ischemia), can rescue dying cells where cellular oxygen content is low. However, the balance of oxygen delivery and oxygen consumption relies on tightly controlled oxygen gradients and compartmentalized redox potential. While therapeutic oxygen delivery can be life-saving, it can disrupt growth and development, impair bioenergetic function, and induce inflammation. Newborns, and premature newborns especially, have features that confer particular susceptibility to hyperoxic injury due to oxidative stress. In this review, we will describe the unique features of newborn redox physiology and antioxidant defenses, the history of therapeutic oxygen use in this population and its role in disease, and clinical trends in the use of therapeutic oxygen and mitigation of neonatal oxidative injury.

Vitamin D and bone minerals in neonates

Osteopenia and rickets remain a problem for high-risk infants, especially preterm infants <1500 g birthweight (very low birth weight, VLBW). The primary cause of osteopenia in VLBW infants is a low intake of calcium and phosphorus compared to requirements for the rapidly growing skeleton. Human milk is a relatively low mineral containing substance and cannot meet the bone mineral needs of very low birth weight infants. As such, most VLBW infants need additional bone minerals and in many neonatal care units these are provided as part of human milk fortificants or specialized infant formulas. In some nurseries, these are given to all infants < 1800-2000 g birthweight. Management of full-term infants who are small for gestational age at birth is less clear, but in general bone mineral content is associated more with body size than gestational age and supplementation is often provided to these infants. Although all infants, including preterm ones need a source of vitamin D, the benefits of providing high doses of vitamin D to healthy preterm neonates is unproven. Some evidence indicates that most calcium absorption is non-vitamin D dependent in the first weeks of life in both preterm and term infants. However, after achieving full feeds in the preterm infant, it is prudent to provide vitamin D at amounts comparable to that used in full-term infants. Higher doses increase serum 25-hydroxyvitamin D levels more rapidly, but evidence is inconclusive as to the relative benefits vs possible risks of higher doses. In healthy full-term infants, although vitamin D provision via supplement drops to the breastfed infant, high dose maternal supplementation to the lactating mother or infant formula is generally recommended, the current evidence only strongly supports its use in identified at-risk infants.

Oxygen Toxicity to the Immature Lung-Part II: The Unmet Clinical Need for Causal Therapy

Oxygen toxicity continues to be one of the inevitable injuries to the immature lung. Reactive oxygen species (ROS) production is the initial step leading to lung injury and, subsequently, the development of bronchopulmonary dysplasia (BPD). Today, BPD remains the most important disease burden following preterm delivery and results in life-long restrictions in lung function and further important health sequelae. Despite the tremendous progress in the pathomechanistic understanding derived from preclinical models, the clinical needs for preventive or curative therapies remain unmet. This review summarizes the clinical progress on guiding oxygen delivery to the preterm infant and elaborates future directions of research that need to take into account both hyperoxia and hypoxia as ROS sources and BPD drivers. Many strategies have been tested within clinical trials based on the mechanistic understanding of ROS actions, but most have failed to prove efficacy. The majority of these studies were tested in an era before the latest modes of non-invasive respiratory support and surfactant application were introduced or were not appropriately powered. A comprehensive re-evaluation of enzymatic, antioxidant, and anti-inflammatory therapies to prevent ROS injury is therefore indispensable. Strategies will only succeed if they are applied in a timely and vigorous manner and with the appropriate outcome measures.

Monitored Supplementation of Vitamin D in Preterm Infants: A Randomized Controlled Trial

Appropriate supplementation of vitamin D can affect infections, allergy, and mental and behavioral development. This study aimed to assess the effectiveness of monitored vitamin D supplementation in a population of preterm infants. 109 preterm infants (24 0/7–32 6/7 weeks of gestation) were randomized to receive 500 IU vitamin D standard therapy (n = 55; approximately 800–1000 IU from combined sources) or monitored therapy (n = 54; with an option of dose modification). 25-hydroxyvitamin D [25(OH)D] concentrations were measured at birth, 4 weeks of age, and 35, 40, and 52 ± 2 weeks of post-conceptional age (PCA). Vitamin D supplementation was discontinued in 23% of infants subjected to standard treatment due to increased potentially toxic 25(OH)D concentrations (>90 ng/mL) at 40 weeks of PCA. A significantly higher infants’ percentage in the monitored group had safe vitamin D levels (20–80 ng/mL) at 52 weeks of PCA (p = 0.017). We observed increased vitamin D levels and abnormal ultrasound findings in five infants. Biochemical markers of vitamin D toxicity were observed in two patients at 52 weeks of PCA in the control group. Inadequate and excessive amounts of vitamin D can lead to serious health problems. Supplementation with 800–1000 IU of vitamin D prevents deficiency and should be monitored to avoid overdose.

Expert consensus on clinical management of metabolic bone disease of prematurity (2021)

Metabolic bone disease of prematurity (MBDP) is a systemic bone disease with a reduction in bone mineral content due to disorder of calcium and phosphorus metabolism. There is still a lack of in-depth research and systematic understanding of MBDP in China, and there are many irregularities in clinical management of this disease. Based on relevant studies in China and overseas, Grading of Recommendations Assessment, Development and Evaluation was used to develop the expert consensus on the clinical management of MBDP, which provides recommendations from the following five aspects: high-risk factors, screening/diagnosis, prevention, treatment, and post-discharge follow-up of MBDP, so as to provide relevant practitioners with recommendations on the clinical management of MBDP to reduce the incidence rate of MBDP and improve its short- and long-term prognosis.

Eligibility Criteria and Representativeness of Randomized Clinical Trials That Include Infants Born Extremely Premature: A Systematic Review

OBJECTIVE

To assess the eligibility criteria and trial characteristics among contemporary (2010-2019) randomized clinical trials (RCTs) that included infants born extremely preterm (<28 weeks of gestation) and to evaluate whether eligibility criteria result in underrepresentation of high-risk subgroups (eg, infants born at <24 weeks of gestation).

STUDY DESIGN

PubMed and Scopus were searched January 1, 2010, to December 31, 2019, with no language restrictions. RCTs with mean or median gestational ages at birth of <28 weeks of gestation were included. The study followed the PRISMA guidelines; outcomes were registered prospectively. Data extraction was performed independently by multiple observers. Study quality was evaluated using a modified Jadad scale.

RESULTS

Among RCTs (n = 201), 32 552 infants were included. Study participant characteristics, interventions, and outcomes were highly variable. A total of 1603 eligibility criteria were identified; rationales were provided for 18.8% (n = 301) of criteria. Fifty-five RCTs (27.4%) included infants <24 weeks of gestation; 454 (1.4%) infants were identified as <24 weeks of gestation.

CONCLUSIONS

The present study identifies sources of variability across RCTs that included infants born extremely preterm and reinforces the critical need for consistent and transparent policies governing eligibility criteria.

The association of vitamin D and vitamin E levels at birth with bronchopulmonary dysplasia in preterm infants

BACKGROUND

Despite improvements made in neonatal care, bronchopulmonary dysplasia (BPD) is still the most common respiratory disease in preterm infants. The relationship between the blood contents of vitamin D/E in premature infants and BPD is still controversial.

METHODS

Preterm infants were recruited as the research subjects. On the basis of the inclusion and exclusion criteria, a total of 133 eligible cases were finally included. A total of 63 preterm infants with a clear diagnosis of BPD and 5 preterm infants who died before the diagnosis of BPD were in the case group, and 65 non-BPD preterm infants with equivalent baseline characteristics were in the control group. The BPD group included 38 cases in Grade Ⅰ, 18 cases in Grade Ⅱ, and 12 cases in Grade Ⅲ. The contents of vitamin D and E in the cord blood of different groups were detected by high-performance liquid chromatography and enzyme-linked immunosorbent assay. Correlation analysis adopted the Pearson correlation analytic method.

RESULTS

The serum vitamin D and E levels at birth were remarkably lower in the BPD group than the non-BPD group, both of which were also correlated with the severity of BPD. The vitamin D and E contents were negatively correlated with the oxygen support duration required for premature infants with BPD.

CONCLUSION

This study deepens our understanding of the field of BPD pathogenesis by demonstrating an association between vitamin D/E deficiency and BPD severity, suggesting that vitamin D and E might have potential clinical value in the prognosis and treatment of BPD.

Evaluation of vitamin D protocol in the neonatal intensive care unit at Rush University Medical Center

BACKGROUND

In 2017, the neonatal intensive care unit (NICU) at Rush University Medical Center (RUMC) implemented a protocol to provide individualized vitamin D supplementation dosing for very low-birth-weight (VLBW) and very preterm infants. This study evaluated the association of demographic and socioeconomic factors, vitamin D dose, and health indicators, including bone mineral status, measured by alkaline phosphatase and phosphorus levels; linear growth velocity; and occurrence of fractures.

METHOD

This retrospective cross-sectional study included 227 VLBW or very preterm infants (34 VLBW, 12 very preterm, and 181 VLBW and very preterm) born in and discharged from the RUMC NICU between February 1, 2017, and October 31, 2019. Vitamin D dose was classified as adjusted (supplemental dose of 800 IU/day, n = 169) or standard (recommended dose of 400 IU/day, n = 58), per the protocol. Binary logistic and linear regression models were constructed to test the associations between infant and maternal characteristics and vitamin D dose group and between vitamin D dose group and health indicators.

RESULTS

The analysis found a statistically significant association between maternal age, gestational age, infant birth weight, and race/ethnicity and receipt of an adjusted vitamin D dose. No significant associations were found between health indicators and vitamin D dose.

CONCLUSION

Sociodemographic factors may influence vitamin D deficiency in VLBW and very preterm infants in the NICU. At this time, there is insufficient evidence to support a tailored approach, but further research in this area is warranted.

Association of vitamin D status at birth with pulmonary disease morbidity in very preterm infants

OBJECTIVE

We aimed to assess whether serum 25-hydroxyvitamin D (25(OH)D) levels at birth are associated with pulmonary disease morbidities in very preterm infants.

METHODS

This prospective cohort analysis included 93 infants born before 32 weeks of gestation in the Second Xiangya Hospital of Central South University between March 2016 and February 2017. Participants were classified into three groups according to their 25(OH)D levels at birth. The groups were compared in terms of demographic variables and pulmonary disease morbidities.

RESULTS

The mean serum 25(OH)D level at birth was 35.7 ± 19.1 nmol/L, and 38 (40.9%), 31 (33.3%), and 24 (25.8%) infants had 25(OH)D levels of less than 25 nmol/L, 25-50 nmol/L, and more than or equal to 50 nmol/L, respectively. There was a statistically significant difference in neonatal respiratory distress syndrome (RDS) rates among the three groups (43.6% vs. 35.9% vs. 20.5%, p = .029). The rates of bronchopulmonary dysplasia, apnea, respiratory failure, persistent pulmonary hypertension, and pulmonary hemorrhage did not differ significantly among the groups. Logistic analysis, adjusted for gestational age and birth weight, showed that a low serum 25(OH)D level (<50 nmol/L) was a risk factor for RDS (odds ratio, 0.195; p = .017).

CONCLUSION

There was a high prevalence of low 25(OH)D levels (<50 nmol/L) and an association between vitamin D status and RDS in very preterm infants. However, more research on this association is required.

CYP11A1 Upregulation Leads to Trophoblast Oxidative Stress and Fetal Neurodevelopmental Toxicity That can be Rescued by Vitamin D

During normal pregnancy, the placental trophoblast secretes a variety of steroid hormones and participates in the regulation of maternal physiological functions and fetal development. The CYP11A1 gene encodes the cholesterol side-chain cleavage enzyme P450scc, which catalyzes the production of pregnenolone from cholesterol, which is the first step in the synthesis of all steroid hormones. Under the influence of genetic susceptibility and certain environmental factors, such as drugs and toxins, the expression of CYP11A1 can be upregulated, thereby affecting steroid metabolism and physiological functions in trophoblast cells, as well as fetal development. Here, we demonstrate that upregulation of CYP11A1 in the BeWo cell line triggers excessive mitochondrial oxidative stress, leads to mitochondrial damage and interleukin-6 release, and contributes to the inhibition of proliferation and DNA damage in neuronal stem cells (NSCs). Furthermore, oxidative stress and inflammation can be ameliorated by vitamin D₃ in a dose-dependent manner, thereby facilitating the rescue of NSC impairment. Our findings reveal the underlying mechanism in which upregulation of CYP11A1 is detrimental to the physiological function of trophoblasts and demonstrate the beneficial effects of vitamin D supplementation in preventing placental and neurodevelopmental damage associated with CYP11A1 upregulation during pregnancy.

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.

Effects of oral vitamin D supplementation on linear growth and other health outcomes among children under five years of age

BACKGROUND

Vitamin D is a secosteroid hormone that is important for its role in calcium homeostasis to maintain skeletal health. Linear growth faltering and stunting remain pervasive indicators of poor nutrition status among infants and children under five years of age around the world, and low vitamin D status has been linked to poor growth. However, existing evidence on the effects of vitamin D supplementation on linear growth and other health outcomes among infants and children under five years of age has not been systematically reviewed.

OBJECTIVES

To assess effects of oral vitamin D supplementation on linear growth and other health outcomes among infants and children under five years of age.

SEARCH METHODS

In December 2019, we searched CENTRAL, PubMed, Embase, 14 other electronic databases, and two trials registries. We also searched the reference lists of relevant publications for any relevant trials, and we contacted key organisations and authors to obtain information on relevant ongoing and unpublished trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs assessing the effects of oral vitamin D supplementation, with or without other micronutrients, compared to no intervention, placebo, a lower dose of vitamin D, or the same micronutrients alone (and not vitamin D) in infants and children under five years of age who lived in any country.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures.

MAIN RESULTS

Out of 75 studies (187 reports; 12,122 participants) included in the qualitative analysis, 64 studies (169 reports; 10,854 participants) contributed data on our outcomes of interest for meta-analysis. A majority of included studies were conducted in India, USA, and Canada. Two studies reported for-profit funding, two were categorised as receiving mixed funding (non-profit and for-profit), five reported that they received no funding, 26 did not disclose funding sources, and the remaining studies were funded by non-profit funding. Certainty of evidence varied between high and very low across outcomes (all measured at endpoint) for each comparison. Vitamin D supplementation versus placebo or no intervention (31 studies) Compared to placebo or no intervention, vitamin D supplementation (at doses 200 to 2000 IU daily; or up to 300,000 IU bolus at enrolment) may make little to no difference in linear growth (measured length/height in cm) among children under five years of age (mean difference (MD) 0.66, 95% confidence interval (CI) -0.37 to 1.68; 3 studies, 240 participants; low-certainty evidence); probably improves length/height-for-age z-score (L/HAZ) (MD 0.11, 95% CI 0.001 to 0.22; 1 study, 1258 participants; moderate-certainty evidence); and probably makes little to no difference in stunting (risk ratio (RR) 0.90, 95% CI 0.80 to 1.01; 1 study, 1247 participants; moderate-certainty evidence). In terms of adverse events, vitamin D supplementation results in little to no difference in developing hypercalciuria compared to placebo (RR 2.03, 95% CI 0.28 to 14.67; 2 studies, 68 participants; high-certainty evidence). It is uncertain whether vitamin D supplementation impacts the development of hypercalcaemia as the certainty of evidence was very low (RR 0.82, 95% CI 0.35 to 1.90; 2 studies, 367 participants). Vitamin D supplementation (higher dose) versus vitamin D (lower dose) (34 studies) Compared to a lower dose of vitamin D (100 to 1000 IU daily; or up to 300,000 IU bolus at enrolment), higher-dose vitamin D supplementation (200 to 6000 IU daily; or up to 600,000 IU bolus at enrolment) may have little to no effect on linear growth, but we are uncertain about this result (MD 1.00, 95% CI -2.22 to 0.21; 5 studies, 283 participants), and it may make little to no difference in L/HAZ (MD 0.40, 95% CI -0.06 to 0.86; 2 studies, 105 participants; low-certainty evidence). No studies evaluated stunting. As regards adverse events, higher-dose vitamin D supplementation may make little to no difference in developing hypercalciuria (RR 1.16, 95% CI 1.00 to 1.35; 6 studies, 554 participants; low-certainty evidence) or in hypercalcaemia (RR 1.39, 95% CI 0.89 to 2.18; 5 studies, 986 participants; low-certainty evidence) compared to lower-dose vitamin D supplementation. Vitamin D supplementation (higher dose) + micronutrient(s) versus vitamin D (lower dose) + micronutrient(s) (9 studies) Supplementation with a higher dose of vitamin D (400 to 2000 IU daily, or up to 300,000 IU bolus at enrolment) plus micronutrients, compared to a lower dose (200 to 2000 IU daily, or up to 90,000 IU bolus at enrolment) of vitamin D with the same micronutrients, probably makes little to no difference in linear growth (MD 0.60, 95% CI -3.33 to 4.53; 1 study, 25 participants; moderate-certainty evidence). No studies evaluated L/HAZ or stunting. In terms of adverse events, higher-dose vitamin D supplementation with micronutrients, compared to lower-dose vitamin D with the same micronutrients, may make little to no difference in developing hypercalciuria (RR 1.00, 95% CI 0.06 to 15.48; 1 study, 86 participants; low-certainty evidence) and probably makes little to no difference in developing hypercalcaemia (RR 1.00, 95% CI 0.90, 1.11; 2 studies, 126 participants; moderate-certainty evidence). Four studies measured hyperphosphataemia and three studies measured kidney stones, but they reported no occurrences and therefore were not included in the comparison for these outcomes.

AUTHORS' CONCLUSIONS

Evidence suggests that oral vitamin D supplementation may result in little to no difference in linear growth, stunting, hypercalciuria, or hypercalcaemia, compared to placebo or no intervention, but may result in a slight increase in length/height-for-age z-score (L/HAZ). Additionally, evidence suggests that compared to lower doses of vitamin D, with or without micronutrients, vitamin D supplementation may result in little to no difference in linear growth, L/HAZ, stunting, hypercalciuria, or hypercalcaemia. Small sample sizes, substantial heterogeneity in terms of population and intervention parameters, and high risk of bias across many of the included studies limit our ability to confirm with any certainty the effects of vitamin D on our outcomes. Larger, well-designed studies of long duration (several months to years) are recommended to confirm whether or not oral vitamin D supplementation may impact linear growth in children under five years of age, among both those who are healthy and those with underlying infectious or non-communicable health conditions.

Vitamin D in Preterm and Full-Term Infants

Vitamin D is necessary for the active (transcellular) absorption of calcium and for skeletal health. Inadequate vitamin D in infants leads to increased risks of poor bone mineralization and ultimately rickets. Rickets is uncommon in full-term infants with a much higher risk in very premature infants. However, the primary cause of rickets in premature infants is a deficiency of calcium and phosphorus, not vitamin D. Available research, as well as most guidelines, recommend an intake of 400 IU daily of vitamin D as adequate for bone health in preterm and full-term infants. Higher doses have not been consistently shown to have specific clinical benefits for healthy infants. There are no strong data to support either routine testing of serum 25-hydroxyvitamin D or targeting high serum 25-hydroxyvitamin D levels (e.g., 30 ng/mL) in healthy preterm or full-term infants. Vitamin D is commonly provided to infants via drops for breastfed babies or via infant formula, although alternative dosing approaches exist for breastfed infants, which some families may prefer. These include the use of drops placed on the mother's breast, dissolvable doses, and high maternal doses (approximately 6,400 IU daily). Infant formula contains vitamin D, and most infants will reach an intake from formula of about 400 IU daily within the first 2 months of life if they are consuming routine cow milk-based formula. Although vitamin D toxicity is very uncommon, caution should be used to avoid extremely concentrated high doses found in some commercially available drops. Infants with liver or kidney disease may need special attention to vitamin D intake and status. Further research is needed to define the role of vitamin D in non-bone health outcomes of infants and to identify methods to enhance compliance with current recommendations for vitamin D intake in infants.

Review of bioequivalence studies of cholecalciferol drugs

Introduction: The general requirements for assessing bioequivalence of endogenous drugs are described in the relevant guidelines, but they do not provide a complete picture of how to adequately develop a design of such a study. The aim of this article is to offer recommendations on the development of a design for bioequivalence studies of endogenous drugs, using cholecalciferol as an example.

Materials and methods: A systematic review of our database on the results of bioequivalence studies of generic drugs revealed one study of cholecalciferol drugs, which was performed using a simple cross-over design. The study involved 24 healthy adult subjects. The data of 24 volunteers were retrospectively analyzed to identify endogenous cholecalciferol concentrations and intraindividual variability (CVintra) for Cmax and AUC0-t. As part of a retrospective analysis, we also assessed gender differences of pharmacokinetics.

Results and discussion: Assessment of the bioequivalence of cholecalciferol drugs was complicated by the presence of endogenous concentrations of cholecalciferol for the tested drug – 1.27 (±0.55) ng/ml and for the reference drug – 0.98 (±0.55) ng/ml. The results of the analysis of the intraindividual variability of Cmax and AUC0-72 of the tested and reference drugs showed the following CVintra values – 22.80% and 21.58%, respectively. A comparative analysis of pharmacokinetic parameters did not reveal statistically significant gender differences. The article presents approaches to the planning of future bioequivalence studies of cholecalciferol drugs.

Conclusion: Cholecalciferol is not a highly variable drug; however, it relates to drugs – analogues of endogenous compounds, which requires determining the endogenous concentrations.

Antimicrobial and micronutrient interventions for the management of infants under 6 months of age identified with severe malnutrition: a literature review

BACKGROUND

Infants under 6 months (U6M) contribute a significant proportion of the burden and mortality of severe malnutrition globally. Evidence of underlying aetiology in this population is sparse, but it is known that the group includes ex-preterm and low birthweight (LBW) infants. They represent a unique population given their dependence on breastmilk or a safe, secure alternative. Nutrition agencies and health providers struggle to make programming decisions on which interventions should be provided to this group based upon the 2013 WHO Guidelines for the 'Management of Severe Acute Malnutrition in Infants and Young Children' since there are no published interventional trial data focussed on this population. Interim guidance for this group might be informed by evidence of safety and efficacy in adjacent population groups.

METHODOLOGY

A narrative literature review was performed of systematic reviews, meta-analyses and randomised controlled trials of antimicrobial and micronutrient interventions (antibiotics, deworming, vitamin A, vitamin D, iron, zinc, folic acid and oral rehydration solution (ORS) for malnutrition) across the population groups of low birthweight/preterm infants, infants under 6 months, infants and children over 6 months with acute malnutrition or through supplementation to breastfeeding mothers. Outcomes of interest were safety and efficacy, in terms of mortality and morbidity.

RESULTS

Ninety-four articles were identified for inclusion within this review. None of these studied interventions exclusively in severely malnourished infants U6M. 64% reported on the safety of studied interventions. Significant heterogeneity was identified in definitions of study populations, interventions provided, and outcomes studied. The evidence for efficacy and safety across population groups is reviewed and presented for the interventions listed.

CONCLUSIONS

The direct evidence base for medical interventions for severely malnourished infants U6M is sparse. Our review identifies a specific need for accurate micronutrient profiling and interventional studies of micronutrients and oral fluid management of diarrhoea amongst infants U6M meeting anthropometric criteria for severe malnutrition. Indirect evidence presented in this review may help shape interim policy and programming decisions as well as the future research agenda for the management of infants U6M identified as malnourished.

Reassessing vitamin D supplementation in preterm infants: a prospective study and review of the literature

Objectives Recommendations for vitamin D (VitD) intake and target serum levels of 25(OH)D in preterm infants are diverse. We hypothesized that preterm infants with low birth weight (BW) have low dietary intake of VitD and therefore should be supplemented with higher amounts of VitD. Methods Infants with BW < 2 kg were supplemented with 600 units of VitD a day during the first 2-6 weeks of life, whereas infants with BW>2 kg continued with the routine supplementation of 400 units of VitD daily. Serum levels of 25(OH)D, calcium, phosphorous, alkaline phosphatase (AP) and parathyroid hormone (PTH) were assessed 24 h after birth and before discharge. The total daily intake of vitD was calculated in each infant. Results Sixty-two infants were enrolled, 49 with BW < 2 kg. After birth, only 24% had sufficient levels of 25(OH)D, whereas before discharge 45 of 54 infants (83%) available for analysis reached sufficient levels of 25(OH)D. All 54 infants demonstrated significant elevation in serum levels of calcium, phosphorous, AP and significant reduction in PTH levels. The total daily intake of VitD was lower than recommended (800-1000 IU/d) in 16 of 45 infants with BW < 2 kg (36%) and in all nine infants with BW>2 kg. Nevertheless, only 2 of 25 infants with insufficient intake of VitD demonstrated insufficient levels of serum 25(OH)D. No case of vitamin D excess was recorded. Conclusions Increased supplementation of VitD (600 IU/d) for premature newborns with BW < 2 kg is effective in increasing both total daily intake of VitD and serum levels of 25(OH)D.

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

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

Nutrients and Microbiota in Lung Diseases of Prematurity: The Placenta-Gut-Lung Triangle

Cardiorespiratory function is not only the foremost determinant of life after premature birth, but also a major factor of long-term outcomes. However, the path from placental disconnection to nutritional autonomy is enduring and challenging for the preterm infant and, at each step, will have profound influences on respiratory physiology and disease. Fluid and energy intake, specific nutrients such as amino-acids, lipids and vitamins, and their ways of administration -parenteral or enteral-have direct implications on lung tissue composition and cellular functions, thus affect lung development and homeostasis and contributing to acute and chronic respiratory disorders. In addition, metabolomic signatures have recently emerged as biomarkers of bronchopulmonary dysplasia and other neonatal diseases, suggesting a profound implication of specific metabolites such as amino-acids, acylcarnitine and fatty acids in lung injury and repair, inflammation and immune modulation. Recent advances have highlighted the profound influence of the microbiome on many short- and long-term outcomes in the preterm infant. Lung and intestinal microbiomes are deeply intricated, and nutrition plays a prominent role in their establishment and regulation. There is an emerging evidence that human milk prevents bronchopulmonary dysplasia in premature infants, potentially through microbiome composition and/or inflammation modulation. Restoring antibiotic therapy-mediated microbiome disruption is another potentially beneficial action of human milk, which can be in part emulated by pre- and probiotics and supplements. This review will explore the many facets of the gut-lung axis and its pathophysiology in acute and chronic respiratory disorders of the prematurely born infant, and explore established and innovative nutritional approaches for prevention and treatment.

Mineral and nutritional requirements of preterm infant

Preterm infants are at risk of growth failure and metabolic bone disease due to insufficient nutrient supply in postnatal life. An ample provision of protein, energy, calcium and phosphates through parenteral or/and enteral nutrition is crucial for bone growth and mineralization. Additional vitamin D supplementation improves bone mineralization and enhance intestinal absorption of minerals.

Association of Protein and Vitamin D Intake With Biochemical Markers in Premature Osteopenic Infants: A Case-Control Study

Osteopenia in preterm infants (OP) remains an important challenge and is largely dependent on nutritional post-natal intake of factors influencing bone mineralization. We conducted a prospective case-control study to evaluate the importance of protein and vitamin D intake in OP among neonates with birth weight <1,250 g. Simultaneous serum parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium (Ca), phosphorus (P), vitamin D and protein levels were measured during the first six post-natal weeks. At 6 weeks of age, OP was evaluated using wrist radiographs. Comparisons were analyzed using multivariate linear regression, receiver operating characteristic curves, χ2 and Wilcoxon Rank Sum. Of the 26 premature infants enrolled, 13 developed radiographic OP. Daily protein intake (coef = -0.40, p = 0.001) and vitamin D concentrations (21 ± 5.7 ng/ml) were significantly lower in the OP group compared to non-OP subjects. ALP concentration exceeding 619 IU/L, sensitivity of 76.9% and specificity of 75%, was predictive of OP at 6 weeks post-natally. PTH levels were higher at 6 weeks in OP subjects (193 ± 102.5 pg/ml, p < 0.001) compared to non-OP subjects. The findings in this study support the role of vitamin D and protein intake in the development of OP in VLBW infants and inform future practice and research on best practices for OP management.

Vitamin and Mineral Supplementation Practices in Preterm Infants: A Survey of Australian and New Zealand Neonatal Intensive and Special Care Units

Preterm infants are at increased risk of micronutrient deficiencies as a result of low body stores, maternal deficiencies, and inadequate supplementations. The aim of this survey was to investigate current vitamin and mineral supplementation practices and compare these with published recommendations and available evidence on dosages and long-term outcomes of supplementations in preterm infants. In 2018, a two-part electronic survey was emailed to 50 Australasian Neonatal Dietitians Network (ANDiN) member and nonmember dietitians working in neonatal units in Australia and New Zealand. For inpatients, all units prescribed between 400 and 500 IU/day vitamin D, compared to a recommended intake range of 400–1000 IU/day. Two units prescribed 900–1000 IU/day at discharge. For iron, 83% of respondents prescribed within the recommended intake range of 2–3 mg/kg/day for inpatients. Up to 10% of units prescribed 6 mg/kg/day for inpatients and at discharge. More than one-third of units reported routine supplementations of other micronutrients, including calcium, phosphate, vitamin E, and folic acid. There was significant variation between neonatal units in vitamin and mineral supplementation practices, which may contribute to certain micronutrient intakes above or below recommended ranges for gestational ages or birth weights. The variations in practice are in part due to differences in recommended vitamin and mineral intakes between expert groups and a lack of evidence supporting the recommendations for supplementations.

Vitamin D status of very low birth weight infants at birth and the effects of generally recommended supplementation on their vitamin D levels at discharge

Purpose: To evaluate vitamin D status in mothers and their very low birth weight infants (VLBW) at birth (umbilical cord blood) and at discharge with currently recommended supplementation of vitamin D.Methods: Ninety-four infants with birth weight less than 1500 g completed the study. The total daily vitamin D intake was 800-1000 IU. We examined 25-hydroxyvitamin-D [25(OH)D] levels in maternal serum before labor, in cord blood, and in infants' serum at discharge.Results: Median (IQR) serum 25(OH)D was 21 (14-36) nmol/l [8 (6-15) ng/ml] in cord blood, and 46 (37-60) nmol/l [18 (15-24) ng/ml] at discharge. Serum 25(OH)D was <50 nmol/L in 71.3% of mothers, in 91.5% of cord blood samples, and in almost 60% of preterm newborns at discharge (after 8 weeks of supplementation). Serum 25(OH)D was <75 nmol/L in 88.3% of mothers, in 97.9% of cord blood samples, and in 91.4% of preterm newborns at discharge.Conclusions: In our cohort, we found that due to the very high prevalence of 25(OH)D deficiency among mothers, the current generally recommended dose of vitamin D (800-1000 IU per day) for VLBW infants was unable to improve vitamin D levels above the desired 50 or even 75 nmol/L before discharge.

Immature megalin expression in the preterm neonatal kidney is associated with urinary loss of vitamin carrier proteins

BACKGROUND

Vitamin A and D deficiencies are common in preterm infants. Megalin is an endocytic receptor in the proximal tubule, which reabsorbs retinol-binding protein (RBP) and vitamin D-binding protein (VDBP). Although the proximal tubule is immature in preterm infants, little is known about megalin expression during kidney development. In this study, we establish the abundance of megalin in the developing human kidney and its relationship to the urinary excretion of vitamin carriers in preterm infants.

METHODS

We analyzed a postmortem group (20-40 weeks gestation), where we used morphometric means of measuring megalin and its ligands in kidney tissue and a living group of patients (28-40 weeks), where urinary RBP and VDBP were measured.

RESULTS

The presence of megalin, RBP, and VDBP increased in the proximal tubule through gestation. At birth the urinary concentration of RBP and VDBP were higher in the 28-32 week group compared to the 38-40 week group and a significant inverse correlation of tissue megalin and urinary loss of RBP and VDBP existed.

CONCLUSIONS

Preterm infants experience vitamin carrier protein losses, which are associated with decreased megalin expression. This developmental expression of megalin in the kidney has clinical implications in the prevention of vitamin deficiencies in preterm babies.

Do Maternal Vitamin D Levels Influence Vitamin D Levels in Preterm Neonates?

Objective

To determine the prevalence of Vitamin D (VitD) deficiency/insufficiency in mothers of preterm neonates less than or equal to 32 weeks of gestation and determine if the current level of VitD supplementation used for preterm neonates is appropriate.

Design

Prospective study from 10^th May 2015 to 1^st November 2016.

Setting

Neonatal Intensive Care Unit at the Canberra Hospital.

Patients

Mothers and their preterm neonates born less than or equal to 32 weeks gestation.

Interventions

Maternal VitD levels were obtained within 3-4 days following delivery. Neonatal VitD levels were obtained in the first 3-4 days of life, at 3-4 weeks of age, and at 6-8 weeks of age. Demographic data and data on VitD intake from parenteral nutrition, enteral feeds, and vitamin supplementation agents were collected.

Results

70 neonates were enrolled into the study. Median gestation was 29 (27-30) weeks and median birth weight 1197 (971.2-1512.5) grams. Median maternal VitD level was 54.5 (36-70.7) nmol/L, median neonatal Vit D level at birth was 57 (42-70) nmol/L. Median Vit D level at 3 weeks and 6 weeks were 63.5 nmol/L (53-80.2) nmol/L and 103 (71.5-144) nmol/L respectively. 22/55 (40%) mothers were VitD deficient/insufficient. 25/70 (36%) neonates were VitD deficient/insufficient at birth. Of those neonates who were VitD deficient/insufficient at birth 5/25(10%) were deficient/insufficient at 6 weeks. The median intake of VitD at 6 weeks was 826.5 (577.5-939.5) IU/day.

Conclusions

VitD deficiency/insufficiency in mothers of preterm neonates and in preterm neonates at birth is common. Routine screening of maternal VitD and their preterm neonates along with individualized supplementation regimens in mothers and preterm infants may optimize VitD status and reduce risk of ongoing VitD deficiency/insufficiency.

Vitamin D and associated perinatal-neonatal outcomes among extremely low-birth-weight infants

OBJECTIVE

To evaluate vitamin D inadequacy among extremely low-birth-weight (ELBW, <1000 g) infants and the association between circulating vitamin D concentrations and perinatal-neonatal outcomes.

STUDY DESIGN

Prospective cohort study of ELBW infants in the neonatal ICU. Blood was collected within the first 3 days after birth after obtaining informed consent. Circulating 25-hydroxyvitamin D concentrations (25(OH)D) were quantified using liquid chromatography-tandem mass spectroscopy and classified as vitamin D deficient, insufficient, or adequate ( < 20, 20-30, or > 30 ng/mL, respectively). Associations between 25(OH)D and perinatal-neonatal outcomes were determined by multivariable regression, adjusted for covariates that differ in the bivariate analysis.

RESULTS

Of the 60 ELBW infants enrolled, 13 (22%) were vitamin D deficient, 15 (25%) were insufficient, and 32 (53%) were adequate. 25(OH)D levels were positively associated with fetal growth restriction and prolonged rupture of the membranes.

CONCLUSIONS

Vitamin D inadequacy was frequent among ELBW infants. Circulating vitamin D concentrations were significantly associated with perinatal outcomes in this contemporary cohort.

Effect of Vitamin D Supplementation on Recurrent Wheezing in Black Infants Who Were Born Preterm: The D-Wheeze Randomized Clinical Trial

IMPORTANCE

Black infants born preterm face high rates of recurrent wheezing throughout infancy. Vitamin D supplementation has the potential to positively or negatively affect wheezing through modulation of the pulmonary and immune systems.

OBJECTIVE

To assess the effectiveness of 2 vitamin D dosing strategies in preventing recurrent wheezing.

DESIGN, SETTING, AND PARTICIPANTS

A randomized clinical trial enrolled 300 black infants born at 28 to 36 weeks' gestation between January 2013 and January 2016 at 4 sites in the United States, and followed them up through March 2017. Randomization was stratified by site and maternal milk exposure.

INTERVENTIONS

Patients were enrolled prior to discharge from the neonatal intensive care unit or newborn nursery and received open-label multivitamin until they were consuming 200 IU/d of cholecalciferol from formula or fortifier added to human milk, after which they received either 400 IU/d of cholecalciferol until 6 months of age adjusted for prematurity (sustained supplementation) or placebo (diet-limited supplementation). One-hundred fifty three infants were randomized to the sustained group, and 147 were randomized to the diet-limited group.

MAIN OUTCOMES AND MEASURES

Recurrent wheezing by 12 months' adjusted age was the primary outcome.

RESULTS

Among 300 patients who were randomized (mean gestational age, 33 weeks; median birth weight, 1.9 kg), 277 (92.3%) completed the trial. Recurrent wheezing was experienced by 31.1% of infants in the sustained supplementation group and 41.8% of infants in the diet-limited supplementation group (difference, -10.7% [95% CI, -27.4% to -2.9%]; relative risk, 0.66 [95% CI, 0.47 to 0.94]). Upper and lower respiratory tract infections were among the most commonly reported adverse events. Upper respiratory infections were experienced by 84 of 153 infants (54.9%) in the sustained group and 83 of 147 infants (56.5%) in the diet-limited group (difference, -1.6% [95% CI, -17.1% to 7.0%]). Lower respiratory infections were experienced by 33 of 153 infants (21.6%) in the sustained group and 37 of 147 infants (25.2%) in the diet-limited group (difference, -3.6% [95% CI, -16.4% to 4.4%]).

CONCLUSIONS AND RELEVANCE

Among black infants born preterm, sustained supplementation with vitamin D, compared with diet-limited supplementation, resulted in a reduced risk of recurrent wheezing by 12 months' adjusted age. Future research is needed to better understand the mechanisms and longer-term effects of vitamin D supplementation on wheezing in children born preterm.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01601847.

Vitamin D in pediatric age: consensus of the Italian Pediatric Society and the Italian Society of Preventive and Social Pediatrics, jointly with the Italian Federation of Pediatricians

Vitamin D plays a pivotal role in the regulation of calcium-phosphorus metabolism, particularly during pediatric age when nutritional rickets and impaired bone mass acquisition may occur.Besides its historical skeletal functions, in the last years it has been demonstrated that vitamin D directly or indirectly regulates up to 1250 genes, playing so-called extraskeletal actions. Indeed, recent data suggest a possible role of vitamin D in the pathogenesis of several pathological conditions, including infectious, allergic and autoimmune diseases. Thus, vitamin D deficiency may affect not only musculoskeletal health but also a potentially wide range of acute and chronic conditions. At present, the prevalence of vitamin D deficiency is high in Italian children and adolescents, and national recommendations on vitamin D supplementation during pediatric age are lacking. An expert panel of the Italian Society of Preventive and Social Pediatrics reviewed available literature focusing on randomized controlled trials of vitamin D supplementation to provide a practical approach to vitamin D supplementation for infants, children and adolescents.

Vitamin D deficiency and respiratory morbidity among African American very low birth weight infants

BACKGROUND

Very low birth weight infants (VLBWI) have unexplained variation in respiratory morbidity, including respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD). We examined a potential association to serum 25-hydroxyvitamin D (s-25OHD) on day one.

STUDY DESIGN

Prospective, observational study on 89 VLBWI (≤1250 g). S-25OHD (day one and 21) and respiratory severity score (RSS) (day one) were examined. Other respiratory morbidities including BPD were compared between infants with s-25OHD ≤ 10 ng/ml (deficient) versus >10 ng/ml (adequate).

RESULTS

Eighty one neonates (91%) were African Americans. The mean (SD) birthweight was 868 (229) g, gestational age 27 (2) weeks. On day one, mean (SD) s-25OHD was 15.48 (8.31) ng/ml, with 32 (37%) being vitamin D deficient. The deficiency and adequate VLBWI groups had similar birthweight; 860 (262) vs 873 (210) g, and gestational age; 27 (2) vs 27 (2) weeks. In 78 survivors, s-25OHD rose from 15.48 (8.31) ng/ml day one to 52.36 (22.49) ng/ml day 21 after supplementation, p < 0.001. On day one, increasing RSS was inversely related to s-25OHD, trend p = 0.054. Compared to the adequate group, the deficiency group had higher RSS (5.0 ± 2.7 vs 3.6 ± 1.9), required surfactant therapy more frequently (91% vs 72%), and needed home oxygen therapy more often (48% vs 26%), p ≤ 0.05 for all. Among infants with BPD, the severity of disease was inversely related to s-25OHD, trend p < 0.09.

CONCLUSION

Lower levels of s-25OHD were associated with increased severity of RDS and BPD among a cohort of mostly African American VLBWI.

Serum 25 Hydroxy Vitamin D Levels in Very Low Birth Weight Infants Receiving Oral Vitamin D Supplementation

BACKGROUND AND OBJECTIVE

Vitamin D supplementation in preterm infants has been recommended by American Academy of Pediatrics (AAP); however, its efficacy and safety has not been well studied. To study 25-hydroxy vitamin D (25OHD) levels as a marker of vitamin D status of very low birth weight infants while on vitamin D supplementation during neonatal intensive care unit hospitalization.

METHODS

Retrospective study of preterm infants with birth weight <1500 g admitted to our unit from January 2013 to December 2015 who were on oral vitamin D3 400 IU supplementation. Serum 25OHD level were checked at 4, 8, and 12 weeks of age or before discharge and the levels were stratified as deficient <20 ng/mL, insufficient 20 to 29 ng/mL, normal 30 to 60 ng/mL, high 61 to 100 ng/mL and very high >100 ng/mL.

RESULTS

A total of 301 infants were enrolled, 186 very low birth weight (VLBW; 1000-1499 g) infants and 115 extremely low birth weight (ELBW; <1000 g) infants. Approximately 80% of both VLBWs and ELBWs had deficient or insufficient 25OHD levels at 4 weeks of age. On oral vitamin D supplementation, VLBW infants increased their 25OHD levels significantly by 8 and 12 weeks of age, whereas ELBW infants lagged behind at 8 weeks and increased their 25OHD levels by 12 weeks of age.

CONCLUSIONS

Eighty percent of ELBW and VLBW infants have either deficient or insufficient vitamin D status at 4 weeks of age. Vitamin D supplementation helps in improving the vitamin D levels, VLBW infants significantly more than ELBW infants. AAP recommendation appears to be safe; however, if using higher supplement dosing, 25OHD level should be monitored to avoid high and very high vitamin D levels.

[Follow-up protocol for newborns of birthweight less than 1500 g or less than 32 weeks gestation]

The mortality of children with a birthweight of less than 1500g or with a gestational age of less than 32 weeks (<1500<32) has decreased significantly in the last 20 years or so. Given the higher risk of disability in these children, follow-up after hospital discharge is considered essential. In this document, the Follow-Up Group of the Spanish Society of Neonatology, in collaboration with the Spanish Society of Paediatric Primary Care, propose a follow-up protocol specific for the<1500<32, which has as its aim to standardise the activities and evaluations according to good practice criteria.