Abstract: Objective To investigate vitamin D nutritional status of pregnant women and their neonates and its influencing factors with serum 25 hydroxy vitamin D [25-(OH)D] for detection index. Methods Pregnant women and their neonates delivered in winter(December 2010 to February 2011) and in summer(June 2011 to August 2011) in Obstetrics and Gynecology of The Second Affiliated Hospital of Hebei North University were selected as the object of study.72 pairs of pregnant women and their neonates were enrolled in the winter group, 40 pairs were enrolled in the summer group.Venous blood of the pregnant women before delivery and umbilical blood after delivery were collected and centrifuged to obtain serum for storing, quantitatively 25-(OH)D levels of serum were determined by ELISA.Classification of vitamin D nutritional status:1)Deficiency:25-(OH)D＜50 nmol/L;2)Insufficiency:50 nmol/L≤25-(OH)D＜75 nmol/L;3)Sufficiency:25-(OH)D≥75 nmol/L. Results 1)25-(OH)D levels of pregnant women were (19.48±7.04)nmol/L in winter and (53.15±17.50)nmol/L in summer, which were significantly lower in winter than in summer.Corresponding 25-(OH)D levels of neonates were respectively (19.95±6.79) nmol/L and (47.39±15.31) nmol/L, which were significantly lower in winter than in summer.2)25-(OH)D levels of pregnant women varied from 9.19 nmol/L to 36.99 nmol/L in winter, which of neonates varied from 7.78 nmol/L to 37.36 nmol/L, vitamin D deficiency rates of pregnant women and neonates were both 100% in winter.25-(OH)D levels of pregnant women varied from 26.72 nmol/L to 103.90 nmol/L in summer, which of neonates varied from 20.76 nmol/L to 79.91 nmol/L, vitamin D deficiency rate was 47.5% of pregnant women in summer, which was 62.5% for the neonates.3)Maternal and neonatal 25-(OH)D levels were positively correlated (r=0.902).4)In winter, there were no difference in serum 25-(OH)D levels between the pregnant women and their neonates living in the urban and rural areas.In summer, the serum 25-(OH)D levels of them living in rural areas were higher than those in urban areas. Conclusions Vitamin D levels of pregnant women and their neonates have a significantly seasonal fluctuation.The pregnant women and their neonates in winter are all vitamin D deficiency, the vitamin D deficiency proportions of pregnant women and their neonates are considerably high even in summer.

Key words: vitamin D, pregnant women, neonates, 25-(OH)D

摘要： 目的 以血清25-(OH)D为检测指标, 了解不同季节、不同居住环境孕妇及其新生儿的维生素D营养状况及母婴血清维生素D的相关性。方法 选取冬季(2010年12月-2011年2月)和夏季(2011年6月-2011年8月)在河北北方学院附属第二医院妇产科正常分娩的孕妇及其新生儿为研究对象。72对孕妇及其新生儿为冬季组, 40对孕妇及其新生儿为夏季组。孕妇于分娩前采集静脉血, 新生儿于娩出后采集脐血, 分离血清。酶联免疫法测定血清25-(OH)D水平。维生素D营养状况采用三分法:1)维生素D缺乏:25-(OH)D＜50 nmol/L;2)维生素D不足:50 nmol/L≤25-(OH)D＜75 nmol/L;3)维生素D充足:25-(OH)D≥75 nmol/L。结果 1)冬季和夏季孕妇血清25-(OH)D水平分别为(19.48±7.04)nmol/L和(53.15±17.50)nmol/L, 冬季显著低于夏季;对应的新生儿脐血25-(OH)D水平分别为(19.95±6.79)nmol/L和(47.39±15.31)nmol/L, 冬季显著低于夏季。2)冬季孕妇25-(OH)D水平为9.19~36.99 nmol/L, 新生儿25-(OH)D水平为7.78~37.36 nmol/L, 冬季孕妇及新生儿维生素D缺乏率为100%。夏季孕妇25-(OH)D水平为26.72~103.90 nmol/L, 新生儿25-(OH)D水平为20.76~79.91 nmol/L, 夏季孕妇和新生儿维生素D缺乏率分别为47.5%和62.5%。3)孕妇与新生儿25-(OH)D水平具有显著正相关(r=0.902)。4)冬季组孕妇及其新生儿25-(OH)D水平无城乡之间的差异;夏季组孕妇及其新生儿25-(OH)D水平存在城乡之间的差异, 农村孕妇及其新生儿25-(OH)D水平高于城市。结论 孕妇及其新生儿25-(OH)D水平存在明显的季节差异。冬季孕妇及其新生儿普遍维生素D缺乏, 即使夏季孕妇及其新生儿维生素D缺乏比率也较高。

关键词: 维生素D, 孕妇, 新生儿, 25-(OH)D