Comparison of Vitamin D Levels in Premature Infants with and without Retinopathy of Prematurity

Vitamin D: What We Know and What We Still Do Not Know About Vitamin D in Preterm Infants-A Literature Review

BACKGROUND/OBJECTIVES

Preterm infants represent a population group at increased risk for vitamin D deficiency (VDD) and for its negative impact on various outcomes like metabolic bone disease or rickets, respiratory complications like respiratory distress syndrome and the development of bronchopulmonary dysplasia, necrotizing enterocolitis, or retinopathy of prematurity.

METHODS

Despite the growing interest in vitamin D research, there is still uncertainty regarding clear recommendations for each high-risk category of premature infants concerning the optimal dosage, optimal product, and timing for initiating vitamin D supplementation to prevent VDD.

RESULTS

An analysis of the literature suggests that early intervention for the optimal enteral supplementation of vitamin D is not only successful in achieving higher 25-hydroxi-vitamin D (25(OH)D) at one month but is also linked with improved outcomes.

CONCLUSIONS

The traditional concepts and current recommendations for assessing vitamin D status and optimal supplementation need to be revised. Since parenteral nutrition, fortified mothers' own milk, and special formula for preterm infants cannot provide adequate vitamin D levels, initiating oral supplementation soon after birth is essential to correct VDD in preterm infants.

Improved linear growth after routine zinc supplementation in preterm very low birth weight infants

BACKGROUND

This study was designed (1) to compare growth, morbidity and mortality in < 33-week gestational age (GA) (very preterm, VPT) or very low birth weight (BW < 1500 grams, VLBW) infants before (Epoch-1) and after implementing routine enteral zinc (Zn) supplementation (Epoch-2) to meet recommendations, and (2) to assess serum Zn levels and associated variables.

METHODS

Single-center prospective cohort of 826 infants. The primary outcome was the change (Δ) in Z-scores of accurate length (Δlengthz), weight and head circumference from birth to discharge home.

RESULTS

In Epoch-2 vs Epoch-1 Δlengthz adjusted for confounding variables increased by 0.27 [95% confidence interval (CI) 0.13, 0.42, P < 0.001]. However, morbidity and mortality did not change. In Epoch-2 Zn decreased with GA and postnatal age: low ( < 0.74 mcg/mL) levels were observed in 51% infants. Retinopathy of prematurity (ROP) was independently associated with the lowest Zn [adjusted odds ratio 0.042 (CI 0.006, 0.306), area under the curve=0.928].

CONCLUSION

Routine enteral Zn supplementation was independently associated with improved linear growth but did not prevent occurrence of low Zn. ROP was independently associated with the lowest Zn.

IMPLICATIONS

Multicenter studies are needed to assess whether dosage of enteral Zn should be increased and whether Zn could help prevent ROP.

IMPACT

Implementation of routine enteral zinc (Zn) supplementation was associated with improved linear growth from birth to discharge and a more frequent physiologic growth curve in preterm very low birth weight infants. Serum Zn levels decreased with gestational age and with postnatal age. Low serum Zn levels were observed frequently despite routine Zn supplementation as currently recommended, which suggests a need to re-evaluate current enteral zinc supplementation guidelines for this population. Retinopathy of prematurity among infants < 33 weeks' gestation was independently associated with low gestational age, low birthweight, stage of bronchopulmonary dysplasia and the lowest serum Zn level.

Correlation between 25-hydroxyvitamin D level of lactating mothers and bone mineral density of infants and analysis of risk factors

Background

Aim was to demonstrate the influencing factors of infant bone mineral density (BMD) and its correlation with serum 25-hydroxyvitamin D (25-(OH)D) in nursing mothers.

Methods

200 children aged 0 č 1 years were rolled into normal group (n=120) and abnormal group (n=80) regarding the results of ultrasound BMD examination. The sunshine duration of infants with different BMD and 25(OH)D, calcium and phosphorus levels of nursing mothers were analyzed, and univariate and multivariate analyses of BMD were implemented.

Results

The results revealed that the sunshine duration and serum 25-(OH)D level of nursing mothers in abnormal group were inferior to those in normal group (P<0.05). Additionally, a notable positive correlation existed between sunshine duration, serum 25-(OH)D level of nursing mothers and BMD (r = 0.911 and 0.503, P<0.05). According to Logistic regression analysis, outdoor activity time 0 č 1 h/d, premature infants, and breastfeeding alone were independent risk factors (RFs) for abnormal BMD in infants, and vitamin D(VD) and calcium supplementation were independent protective factors (P<0.05).

Conclusions

VD and calcium intake, adequate sunshine duration, mixed feeding, and increasing serum 25-(OH)D can reduce the occurrence of abnormal BMD in infants.

The association between serum 25-hydroxyvitamin D levels and retinopathy of prematurity in preterm infants

Objective

This study aimed to investigate the correlation between serum 25-hydroxyvitamin D (25(OH)D) levels and retinopathy of prematurity (ROP) in premature infants one month after birth.

Methods

Preterm infants (gestational age <32 weeks) admitted to the Affiliated Hospital of Qingdao University from 2017 to 2022 were divided into ROP and non-ROP groups based on ROP occurrence any stage. Serum 25(OH)D levels and clinical data were compared between the two groups at 1 month after birth, and the relationship between vitamin D levels and ROP was analyzed.

Results

Among the 217 premature infants included, 55 (25.35%) were in the ROP group, and 162 (74.65%) were in the non-ROP group. The ROP group had lower gestational age and birth weight, longer invasive ventilation (IV), non-invasive ventilation (NIV), and oxygen therapy times compared to the non-ROP group. Apgar scores, cesarean delivery, and antenatal steroids ratios were lower in the ROP group, while sepsis and pulmonary surfactant utilization ratios were higher (all p < 0.05). Significant differences in serum 25-(OH)D levels were observed among children in the non-ROP group (14.20 ± 5.07 ng/ml), ROP treated group (7.891 ± 1.878 ng/ml), and untreated group (12.168 ± 4.354 ng/ml) (p < 0.001). Multivariate regression analysis identified antenatal steroids as protective factors and lower birth weight, serum 25-(OH)D levels, long-term invasive mechanical ventilation, and sepsis as independent risk factors for ROP in premature infants.

Conclusion

Vitamin D, lower birth weight, long-term invasive mechanical ventilation, and sepsis were associated with incidence of ROP in preterm infants. Vitamin D was associated with the severity of ROP, emphasizing the importance of prudent vitamin D supplementation and regular monitoring of serum 25-(OH)D levels.