关键词: 维生素D, 孕妇, 新生儿, 25-(OH)D

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