Factors Influencing Insufficient Serum 25-hydroxyvitamin D Levels in Ex-tremely Premature Infants and Their Relationship with Necrotizing Entero-colitis

ZHANG Min; YANG Li; WANG Wenxiu; YAO Qiuyu

doi:10.3969/j.issn.1002-3429.2025.09.014

Abstract：Objective To analyze the influencing factors of insufficient serum 25-hydroxyvitamin D[25-(OH)D]levels in extremely premature infants,and to investigate the relationship between serum 25-(OH)D levels and necrotizing en-terocolitis(NEC).Methods A total of 200 extremely premature infants admitted from May 2018 to May 2023 were selected.Serum 25-(OH)D levels were measured within 2 h after birth in the infants,and the incidence of insufficient serum 25-(OH)D levels was calculated.Infants with insufficient serum 25-(OH)D levels were included in the insufficient group,while infants with normal serum 25-(OH)D levels were included in the normal group.Clinical data of the two groups were compared,and factors influencing insufficient serum 25-(OH)D levels were analyzed.The incidence of NEC within 28 d af-ter birth was compared between the two groups,and the serum 25-(OH)D levels were compared between infants with and without NEC.The value of serum 25-(OH)D levels in predicting NEC was analyzed.Results The insufficient rate of serum 25-(OH)D levels was 68.50%(137/200).The incidence of maternal gestational diabetes mellitus(GDM)and gestational hypertension(GH)of extremely preterm infants in insufficient serum 25-(OH)D level group was higher than that in the nor-mal group,and the prenatal serum 25-(OH)D levels were lower than those in the normal group(P＜0.01).The birth rate of extremely preterm infants in the insufficient serum25-(OH)D level group during winter and spring[59.12%(81/137)]was higher than that in the normal group[31.75%(20/63)],with a significant difference(P＜0.01).Maternal GDM,GH,prenatal serum 25-(OH)D levels,and the birth season of extremely preterm infants were all influencing factors of insuf-ficient serum 25-(OH)D levels(P＜0.01).The incidence of NEC in the insufficient serum 25-(OH)D level group[17.52%(24/137)]was higher than that in the normal group[4.76%(3/63)],with a significant difference(P＜0.05).The serum 25-(OH)D levels of extremely preterm infants with NEC were lower than those without NEC(P＜0.01).The area under the receiver operating characteristic curve for predicting the occurrence of NEC in extremely preterm infants based on se-rum 25-(OH)D levels was 0.850(95%CI:0.792,0.896),with a sensitivity of 92.59%and a specificity of 71.10%.Conclusion The influencing factors of insufficient serum 25-(OH)D levels in extremely premature infants include maternal GDM,GH,prenatal serum 25-(OH)D levels,and the birth season of the extremely premature infants.Furthermore,insuffi-cient serum 25-(OH)D levels are closely related to the occurrence of NEC.