Clinical Study on the Relationship between Cord Blood 25 Hydroxyvitamin D Levels and Respiratory Distress Syndrome in Preterm Infants

目的：探讨脐血25羟基维生素D [25 hydroxyvitamin D, 25(OH)D]水平与早产儿呼吸窘迫综合征(Respiratory distress syndrome, RDS)的关系，为RDS的预防提供新思路。方法：选择2024年1月至2024年12月日照市人民医院新生儿重症监护室(Neonatal intensive care unit, NICU)收治的243例早产儿纳入研究。早产儿出生时采集脐血测定25(OH)D水平，并根据其水平分为充足组[25(OH)D > 20 ng/mL)]、不足组[25(OH)D 12~20 ng/mL]、缺乏组[25(OH)D Objective: To investigate the relationship between 25-hydroxyvitamin D [25(OH)D] levels in umbilical cord blood and respiratory distress syndrome (RDS) in preterm infants, and to provide new insights for the prevention of RDS. Methods: A total of 243 preterm infants admitted to the neonatal intensive care unit (NICU) of Rizhao People’s Hospital from January 2024 to December 2024 were included in the study. 25(OH)D levels in umbilical cord blood were measured at birth. The infants were divided into sufficient group [25(OH)D > 20 ng/mL], insufficient group [25(OH)D 12~20 ng/mL] and deficient group [25(OH)D < 12 ng/mL] based on 25(OH)D levels. The clinical characteristics of the preterm infants in three groups were compared. Univariate and multivariate logistic regression analyses were used to analyze the effect of 25(OH)D levels in umbilical cord blood on RDS in preterm infants. Results: A total of 243 preterm infants were included in the study, including 70 cases (28.8%) in the sufficient group, 74 cases (30.5%) in the insufficient group and 99 cases (40.7%) in the deficient group. There were statistically significant differences in the application of pulmonary surfactant (PS), the application of PS ≥ 2 times, bronchopulmonary dysplasia (BPD), days of invasive ventilation, days of non-invasive ventilation, days of oxygen therapy and length of hospital stay among the three groups (P < 0.05). Pairwise comparisons between groups showed that the incidence of PS application and PS application ≥ 2 times in the deficient group was higher than that in the sufficient group and the insufficient group (P < 0.05). The days of invasive ventilation, non-invasive ventilation, oxygen therapy and length of hospital stay in the deficient group were longer than those in the sufficient group (P < 0.05). Univariate and multivariate logistic regression analysis showed that 25(OH)D < 12 ng/mL was an independent risk factor for RDS in preterm infants. Conclusion: The incidence of vitamin D deficiency in umbilical cord blood of preterm infants is relatively high. Vitamin D deficiency may increase the risk of RDS in preterm infants.