目的　了解新生儿脐带血维生素D水平现况，探讨脐带血维生素D水平与新生儿生长指标的相关性。方法　共 纳入223对足月单胎母子。问卷法收集母亲孕期信息；测量新生儿出生体质量、头围和身长指标；采用酶联免疫法测定新 生儿脐带血和母亲孕晚期血25(OH)D浓度。结果　脐带血25(OH)D平均浓度为20.7 nmol/L，维生素D缺乏率达82.1%， 其中严重缺乏率为12.1%（<10 nmol/L）。 子代与母亲孕晚期25(OH)D浓度基本一致。脐带血不同25(OH)D 浓度新生儿 的出生季节分布差异有统计学意义（P<0.05），<10 nmol/L组冬春季节所占比例较高。脐带血25(OH)D 浓度与低出生体 质量（LBW）和小于胎龄（SGA）新生儿的发生率均无显著相关（P>0.05）。 控制性别、胎龄、出生季节等变量后，脐带血不 同25(OH)D 浓度组间的出生体质量和头围差异有统计学意义（P<0.05）。 结论　足月新生儿脐带血25(OH)D浓度普遍低， 维生素D缺乏状态与其母亲孕晚期维生素D状况基本一致。脐带血25(OH)D浓度与新生儿出生体质量和头围存在一定相 关性，其具体规律尚有待进一步扩大样本验证。

　Objectives　To detect the cord blood vitamin D level in neonates and to determine the association between the cord blood vitamin D level and neonatal outcomes. Methods　A total of 223 eligible mother-and-singleton-offspring pairs were recruited. The information of mothers’ pregnancy was collected by questionnaires. The weight, length, and head circumference of neonates were measured. The levels of 25(OH)D in cord blood of neonates and in blood of late pregnancy mothers were determined by chemiluminescence immunoassay. Results　The median concentration of 25(OH)D in cord blood was 20.7 nmol/L, and 82.1% of neonate had vitamin D deficiency, and 12.1% had severe vitamin D deficiency (<10 nmol/L). The concentration of 25(OH)D in cord blood was consistent with that in blood of late pregnancy mother. The distribution of concentration of 25(OH)D in cord blood was significantly different in neonates in different seasons of birth (P<0.05). There were more cases <10 nmol/L in winter and spring. The concentration of 25(OH)D in cord blood had no significant associations with the incidences of  low birth weight (LBW) and small for gestational age (SGA) (P>0.05). After the variables of sex, gestational age and birth season are controlled, the birth weight and head circumference were significantly different in neonates with different concentrations of 25(OH)D in cord blood (P<0.05). Conclusions　The concentration of 25(OH)D in cord blood in term neonates was generally lower. The vitamin D status in neonates was consistet with that in their late pregnancy mothers. Cord blood 25(OH) D levels were associated with neonates’ birth weight and head circumference, but it should be confirmed by larger sample size in the future.