Effect of different doses of vitamin D supplementation on preterm infants - an updated meta-analysis

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.

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.

Growth after implementing a donor breast milk program in neonates <33 weeks gestational age or birthweight <1500 grams: Retrospective cohort study

BACKGROUND

Donor breast milk (DBM) feeding has been associated with less growth than formula in preterm infants. Zinc content in DBM is insufficient to support growth in preterm infants.

OBJECTIVE

To compare growth from birth to discharge, macro- and micronutrient intake and the frequency of poor growth before (Epoch-1) and after (Epoch-2) implementing a DBM program.

METHODS

Retrospective cohort study of 1069 infants born at < 33 weeks' gestational age or birthweight < 1500 g and fed using our adjustable feeding protocol with accurate serial length measurements. Growth was assessed by changes in Z-scores of weight, length and fronto-occipital circumference from birth to discharge.

RESULTS

Growth did not decrease significantly in Epoch-2. However, energy and protein intake increased by 5% and frequency of zinc and vitamin D supplementation increased by >30%.

CONCLUSIONS

DBM implementation did not significantly decrease growth from birth to discharge using our adjustable feeding protocol.

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.

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.

Interventions to Prevent Bronchopulmonary Dysplasia in Preterm Neonates: An Umbrella Review of Systematic Reviews and Meta-analyses

IMPORTANCE

Bronchopulmonary dysplasia (BPD) has multifactorial etiology and long-term adverse consequences. An umbrella review enables the evaluation of multiple proposed interventions for the prevention of BPD.

OBJECTIVE

To summarize and assess the certainty of evidence of interventions proposed to decrease the risk of BPD from published systematic reviews.

DATA SOURCES

MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, and Web of Science were searched from inception until November 9, 2020.

STUDY SELECTION

Meta-analyses of randomized clinical trials comparing interventions in preterm neonates that included BPD as an outcome.

DATA EXTRACTION AND SYNTHESIS

Data extraction was performed in duplicate. Quality of systematic reviews was evaluated using Assessment of Multiple Systematic Reviews version 2, and certainty of evidence was assessed using Grading of Recommendation, Assessment, Development, and Evaluation.

MAIN OUTCOMES AND MEASURES

(1) BPD or mortality at 36 weeks' postmenstrual age (PMA) and (2) BPD at 36 weeks' PMA.

RESULTS

A total of 154 systematic reviews evaluating 251 comparisons were included, of which 110 (71.4%) were high-quality systematic reviews. High certainty of evidence from high-quality systematic reviews indicated that delivery room continuous positive airway pressure compared with intubation with or without routine surfactant (relative risk [RR], 0.80 [95% CI, 0.68-0.94]), early selective surfactant compared with delayed selective surfactant (RR, 0.83 [95% CI, 0.75-0.91]), early inhaled corticosteroids (RR, 0.86 [95% CI, 0.75-0.99]), early systemic hydrocortisone (RR, 0.90 [95% CI, 0.82-0.99]), avoiding endotracheal tube placement with delivery room continuous positive airway pressure and use of less invasive surfactant administration (RR, 0.90 [95% CI, 0.82-0.99]), and volume-targeted compared with pressure-limited ventilation (RR, 0.73 [95% CI, 0.59-0.89]) were associated with decreased risk of BPD or mortality at 36 weeks' PMA. Moderate to high certainty of evidence showed that inhaled nitric oxide, lower saturation targets (85%-89%), and vitamin A supplementation are associated with decreased risk of BPD at 36 weeks' PMA but not the competing outcome of BPD or mortality, indicating they may be associated with increased mortality.

CONCLUSIONS AND RELEVANCE

A multipronged approach of delivery room continuous positive airway pressure, early selective surfactant administration with less invasive surfactant administration, early hydrocortisone prophylaxis in high-risk neonates, inhaled corticosteroids, and volume-targeted ventilation for preterm neonates requiring invasive ventilation may decrease the combined risk of BPD or mortality at 36 weeks' PMA.

Effectiveness of feeding supplementation in preterm infants: an overview of systematic reviews

Background

Preterm infants have higher nutrition needs than term infants. The effectiveness of various feeding supplementation was assessed by the improvement of health outcomes in single specific systematic reviews (SRs). The aim of this review was to comprehensively describe the effectiveness of feeding supplementation in promoting health outcomes of preterm infants.

Methods

A literature search was conducted in the PUBMED, EMBASE, Science Direct, Cochrane library, Web of Science, and Wiley online library. SRs selection followed clear inclusion and exclusion criteria. Pairs of reviewers independently applied the criteria to both titles/abstracts and full texts. Screening and data extraction were performed by using the advanced tables. The methodological quality of SRs and the quality of the evidence were carried out according to the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool and the Grades of Recommendation, Assessment, Development, and Evaluation guidelines (GRADE) respectively. A qualitative synthesis of evidence is presented.

Results

Seventeen SRs were included in the review. Fifteen kinds of feeding supplementation were reported in the SRs. In preterm infants, the effectiveness of feeding supplementation in addition to regular breast-feeding was mainly shown in six aspects: physical health, neurodevelopment, biochemical outcomes, other health outcomes, morbidity and all-cause mortality. And the effectiveness of the interventions on health outcomes in preterm infants was found by most systematic reviews. The methodological quality of all the included SRs was high, and most of the evidences was of low or very low quality.

Conclusions

Our results will allow a better understanding of the feeding supplementation in preterm infants. Although the feeling supplements may improve the health outcomes of in preterm infants, the existing evidence is uncertain. Therefore, the clinical use of these supplements should be considered cautiously and more well-designed RCTs are still needed to further address the unsolved problems of the included SRs.

Variation in Neonatal Nutrition Practice and Implications: A Survey of Australia and New Zealand Neonatal Units

Background: Significant global variation exists in neonatal nutrition practice, including in assigned milk composition values, donor milk usage, fortification regimens, probiotic choice and in methods used to calculate and report nutrition and growth outcomes, making it difficult to synthesize data to inform evidence-based, standardized nutritional care that has potential to improve neonatal outcomes. The Australasian Neonatal Dietitians' Network (ANDiN) conducted a survey to determine the degree to which neonatal nutritional care varies across Australia and New Zealand (A&NZ) and to highlight potential implications.

Materials and Methods: A two-part electronic neonatal nutritional survey was emailed to each ANDiN member (n = 50). Part-One was designed to examine individual dietetic practice; Part-Two examined site-specific nutrition policies and practices. Descriptive statistics were used to examine the distribution of responses.

Results: Survey response rate: 88%. Across 24 NICU sites, maximum fluid targets varied (150–180 mL.kg.d⁻¹); macronutrient composition estimates for mothers' own(MOM) and donor (DM) milk varied (Energy (kcal.dL⁻¹) MOM: 65–72; DM 69–72: Protein (g.dL⁻¹): MOM: 1.0–1.5; DM: 0.8–1.3); pasteurized DM or unpasteurized peer-to-peer DM was not available in all units; milk fortification commenced at different rates and volumes; a range of energy values (kcal.g⁻¹) for protein (3.8–4.0), fat (9.0–10.0), and carbohydrate (3.8–4.0) were used to calculate parenteral and enteral intakes; probiotic choice differed; and at least seven different preterm growth charts were employed to monitor growth.

Discussion: Our survey identifies variation in preterm nutrition practice across A&NZ of sufficient magnitude to impact nutrition interventions and neonatal outcomes. This presents an opportunity to use the unique skillset of neonatal dietitians to standardize practice, reduce uncertainty of neonatal care and improve the quality of neonatal research.

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.

Vitamin D Status of Very Low Birth Weight Neonates at Baseline and Follow-up after Daily Intake of 800 IU Vitamin D

INTRODUCTION

Vitamin D deficiency (VDD) is rampant in neonates. Recommendations for supplementation are variable.

METHODS

An observational study was done on less than 32 weeks of very low birth weight neonates to find prevalence of VDD (<20 ng/ml) at baseline; at 38 ± 2 weeks post-menstrual age (PMA) after daily intake of 800 IU vitamin D (vit D). Secondary objectives were to find determinants of VDD, to compare growth in deficient; vit D sufficient (VDS) neonates; to find vit D toxicity.

RESULTS

Of 83 neonates, 81 (97.6%) were VDD at baseline and 5 (6%) at 38 ± 2 weeks PMA. Determinants for VDD at baseline were inadequate maternal sun exposure (p < 0.001) and vit D supplementation (p = 0.007). Factors for VDD at 38 ± 2 weeks PMA were male gender (p = 0.049), morbidities (p = 0.006), ventilation >24 h (<0.001), sepsis (p = 0.032), caffeine (p ≤ 0.001) and missed supplements (p < 0.001). Weight and length gain of VDD to VDS neonates were (6.70 ± 2.40 to 8.96 ± 2.21 g/day); (0.82 ± 0.34 to 1.08 ± 0.37 cm/week), respectively (p < 0.001). Head circumference gain (cm/week) of VDS; VDD neonates was 0.58 ± 0.09; 0.54 ± 0.06 (p = 0.054), respectively. No neonates developed vit D toxicity.

CONCLUSIONS

In preterm VLBW neonates, the prevalence of VDD was 97.6% but decreased by >90% at 38 ± 2 weeks with a daily intake of 800 IU vit D. Inadequate maternal vit D intake and sun exposure determined low baseline vit D status of neonates. Male gender, morbidities, ventilation, sepsis, caffeine, missed vitamin D supplements were determinants of poor vit D status at follow-up. Weight gain and length increments were more in the VDS group.

[A comparative analysis of the efficacy of two vitamin D supplementation regimens in preterm infants: a prospective randomized controlled study]

OBJECTIVE

To study the effect of different vitamin D supplementation regimens on the nutritional status of vitamin D on day 28 after birth in preterm infants with a gestational age of <34 weeks.

METHODS

A total of 59 preterm infants with a gestational age of <34 weeks who were born from October 2018 to October 2019 were enrolled and divided into an observation group with 30 infants and a control group with 29 infants. The infants in the observation group received a single-dose intramuscular injection of vitamin D₃ (10 000 IU/kg), while those in the control group received oral vitamin D₃ drops (900 IU/d) for 25 days. Venous blood samples were collected within 48 hours after birth (before vitamin D₃ supplementation) and on day 28 after birth to measure the serum 25-hydroxyvitamin D [25(OH)D] level.

RESULTS

Within 48 hours after birth, the prevalence rate of vitamin D deficiency (≤15 ng/mL) was 78% among the 59 preterm infants. There were no significant differences in the serum 25(OH)D level and the prevalence rate of vitamin D deficiency between the two groups (P>0.05). Compared with the control group on day 28 after birth, the observation group had a significantly higher serum 25(OH)D level (P<0.05) and a significantly lower prevalence rate of vitamin D deficiency (P<0.05). There were no cases of vitamin D overdose or poisoning.

CONCLUSIONS

In preterm infants with a gestational age of <34 weeks, single-dose intramuscular injection of 10 000 IU/kg vitamin D₃ can significantly increase serum 25(OH)D level on day 28 after birth and safely and effectively reduce the prevalence rate of vitamin D deficiency.

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.

Appropriate and inappropriate vitamin supplementation in children

The vitamin status of a child depends on many factors and most of the clinical studies do not take into account the different access to adequate nutrition of children coming from different countries and the consequent major differences in micronutrients or vitamin deficits between low-income and high-income countries. Vitamin supplements are included in the general field of dietary supplements. There is a large amount of not always factual material concerning vitamin supplements, and this may sometimes create confusion in clinicians and patients. Inadequate information may lead to the risk of attributing beneficial properties leading to their over-use or misuse in the paediatric field. Vitamin supplementation is indicated in all those conditions in which a vitamin deficiency is found, either because of a reduced intake due to reduced availability of certain foods, restrictive diets or inadequate absorption. The lack of guidelines in these fields may lead paediatricians to an improper use of vitamins, both in terms of excessive use or inadequate use. This is due to the fact that vitamin supplementation is often intended as a therapy of support rather than an essential therapeutic tool able to modify disease prognosis. In fact, various vitamins and their derivatives have therapeutic potential in the prevention and treatment of many diseases, especially in emerging conditions of paediatric age such as type 2 diabetes and the metabolic syndrome. The aim of the present article is to analyse the state of the art and consider new perspectives on the role of vitamin supplements in children.

[Protective effect of vitamin D against hyperoxia-induced bronchopulmonary dysplasia in newborn mice]

OBJECTIVE

To investigate the protective effect of vitamin D (VD) against hyperoxia-induced bronchopulmonary dysplasia (BPD) in newborn mice and explore the mechanism.

METHODS

Thirty-six newborn mice were randomly divided into air + VD group, air + saline group, hyperoxia + VD group, and hyperoxia + saline group. In all the groups, saline or VD was administered on a daily basis via intramuscular injection. After 3 weeks of treatment, the mice were weighed and cardiac blood was collected for measurement of serum VD level using ELISA, and histological examination of the lungs was performed. Radial alveolar counting (RAC) and alveolar secondary interval volume density were measured using image analysis software. The expression levels of vascular endothelial cell growth factor (VEGF) and VEGF receptor 2 (VEGFR2) in the lung tissues were detected using Western blotting.

RESULTS

The weight gain rate of the mice and the weight of the lungs were significantly higher in air + saline group and air + VD group than in the hyperoxia + saline group. The RAC was significantly lower in hyperoxic+saline group than that in hyperoxia+VD group (P &lt; 0.001), and was significantly higher in hyperoxic+VD (125 times) than in hyperoxia + VD (1250 times) group (P &lt; 0.01). The alveolar secondary protrusion count was significantly higher in hyperoxic+VD (1250 times) group than in hyperoxic+saline group (P &lt; 0.001), and was significantly higher in hyperoxia+VD (125 times) group than in hyperoxia + VD (1250 times) group (P &lt; 0.01). Compared with that in air + saline group, VEGFR2 expression was significantly lowered in hyperoxia+saline group (P &lt; 0.05) and in air+VD group (P &lt; 0.05); VEGFR2 expression was significantly higher in hyperoxia+VD (1250 times) group than in hyperoxia+saline group (P &lt; 0.001) and hyperoxia+VD (125 times) group (P &lt; 0.001); VEGFR2 expression was significantly higher in hyperoxia+VD (125 times) group than in hyperoxia+ saline group (P &lt; 0.05).

CONCLUSIONS

In newborn mice with BPD, VD supplement can increase the weight of the lungs and promote lung maturation, and a higher concentration of VD can better protect the lungs and promote the growth of pulmonary blood vessels.

Bronchopulmonary Dysplasia: An Update on Experimental Therapeutics

Bronchopulmonary dysplasia (BPD) is a chronic inflammatory lung disease that affects thousands of newborns and infants every year. Although it is accepted that BPD results from lung damage and inflammation triggered by mechanical ventilation and hyperoxia, the causes and molecular events leading to lung damage and arrested development remain unknown. While recent advances in neonatal care have improved the survival of very low-weight infants, the rates of BPD have not improved accordingly. This is mainly due to our limited understanding of the disease’s pathogenesis and the effective therapeutic options available. Current therapeutics for BPD involve ventilation management, steroid treatment, and administration of various agents, such as pulmonary surfactant, caffeine, vitamin A, nitric oxide, and stem cells. However, the efficacy of these agents in preventing and ameliorating BPD symptoms varies depending on the populations studied and the disease stage. As the field moves towards personalised therapeutic approaches, this review summarises clinical and experimental studies conducted in various models, aiming to increase understanding of the cellular and molecular mechanisms by which these agents can prevent or treat BPD. Due to the increasing number of extremely premature infants, it is imperative that we continue to work towards understanding the mechanisms of BPD pathogenesis and generating more effective therapeutic options.

Effect of vitamin D supplementation on fasting plasma glucose, insulin resistance and prevention of type 2 diabetes mellitus in non-diabetics: A systematic review and meta-analysis

Increasing epidemiological studies suggest that there is an association between vitamin D deficiency and risk of type 2 diabetes mellitus (T2DM). Therefore, randomized clinical trials (RCTs) have been performed to observe the effect of vitamin D supplementation on preventing T2DM, decreasing fasting plasma glucose (FPG) and improving insulin resistance to confirm the association between vitamin D and T2DM. However, the results of RCTs on controlling FPG level, improving insulin resistance and preventing T2DM in non-diabetics are inconsistent. In the present study, a systematic meta-analysis considering individual variation and intervention strategy was conducted to establish an objective and definitive conclusion. The results suggested that vitamin D supplementation had no significant effect on controlling FPG level, improving insulin resistance or preventing T2DM in non-diabetics in a pooled meta-analysis of 23 articles (containing 28 RCTs). However, stratified analysis indicated that supplementation of vitamin D had differential effects on FPG control, insulin sensitivity improvement and T2DM prevention in individuals with different baseline states: FPG was decreased for those with BMI <25 (P=0.048) or 20≤ 25(OH)D <30 ng/ml (P=0.002); insulin resistance was improved for those with 25(OH)D ≥30 ng/ml (P=0.021); and risk of T2DM was lower for pre-diabetic individuals (P=0.047) or for those with 25≤ BMI <30 (P=0.032). Additionally, the effect on T2DM prevention was improved when the supplement dose was >2,000 IU/day (P=0.047) and with intervention without calcium (P=0.047). Thus, further trials should focus on individual baselines and the supplementation strategy of vitamin D in the prevention of T2DM.

Vitamin D and IL-10 Deficiency in Preterm Neonates With Bronchopulmonary Dysplasia

Introduction: Vitamin D deficiency and inflammation are involved with bronchopulmonary dysplasia (BPD) in preterm neonates; however, the clinical evidence still remains scarce. We hypothesized that vitamin D and inflammatory cytokines may be risk factors for BPD in infants. Methods: Preterm infants born between 28 and 31 weeks' gestation were recruited between January 2016 and 2017. Blood samples were all collected at corresponding time points. Vitamin D was measured using an automatic biochemical analyzer, and inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-10) were measured using ELISA. Results: The baseline characteristics for preterm infants without BPD (non-BPD control, n = 20) or with BPD (n = 19) were similar. In the blood samples collected 24-h post birth, vitamin D was significantly reduced in the BPD neonates (non-BPD vs. BPD, 28.96 ± 3.404 vs. 17.99 ± 2.233 nmol/l, p = 0.0134). Inflammatory cytokines TNF-α, IL-1β, and IL-6 were comparable in both groups. The anti-inflammatory cytokine IL-10, however, was significantly decreased in 24-h blood samples from BPD preterm infants (non-BPD vs. BPD, 44.61 ± 10.48 vs. 11.64 ± 2.351 pg/ml, p = 0.0054). In the BPD infants with mild or moderate disease, vitamin D deficiency was quite similar. IL-10 deficiency, however, was more aggravated in the BPD infants with moderate disease. No changes in Vitamin D or cytokines (TNF-α, IL-1β, IL-6, and IL-10) were observed for blood samples collected 2 or 4 weeks after birth. Conclusion: In our pilot study, Vitamin D and IL-10 levels at 24-h of life were risk factors for the development of BPD in very preterm infants.