目的　分析早产儿出生时血清25(OH)D水平及其影响因素。方法　回顾2012年7月—2014年6月期间出生 的早产儿血清25(OH)D水平，及其出生胎龄、性别、产次、分娩方式、出生季节、出生体质量；母亲的年龄以及妊娠期并发 症等相关因素。结果　共纳入早产儿325例，平均胎龄(33.41±2.29)周，男女之比为1.32:1，平均血清25(OH)D水平为 (37.34±16.17) nmol/L。早产儿维生素D缺乏和不足的发生率分别高达37.8%和41.8%。夏秋季节出生的早产儿血清 25(OH)D水平显著高于冬春季节，差异有统计学意义(P<0.05)；经logistic回归分析示，出生季节、母亲年龄可能是影响 早产儿血清25(OH)D水平的高危因素。结论　早产儿维生素D缺乏和不足发生率较高，影响早产儿维生素D水平的因素 需进一步研究。

Objective　To analyze serum 25(OH)D level and the influence factors in preterm infants. Methods　The data of serum 25(OH)D level in preterm infants born from July 2012 to June 2014 were retrospectively analyzed along with gestational age, gender, parity, delivery mode, birth season, birth weight, age of the mother and pregnancy complications. Results　Totally 325 cases were included and their average gestational age was 33.41±2.29 week, the ratio of male to  dna ycneicfied D nimativ fo ecnedicni ehT .L/lomn 71.61±43.73 saw level D)HO(52 mures egareva dna 1?23.1 saw elamef insufficiency in preterm infants was 37.8% and 41.8% respectively. Serum 25 (OH) D levels in preterm infants born in summer and autumn were higher than those born in winter and spring, and there was statistical difference (P<0.05). Logistic regression analysis showed that birth season and the mother's age may be the risk factors that influence serum 25 (OH) D levels in preterm infants. Conclusion　The incidence of vitamin D deficiency and insufficiency in preterm infants is high, and the factors affecting the level of vitamin D need to be further studied.