Markestad T, Ulstein M, Aksnes L, Aarskog D
Acta Obstet Gynecol Scand. 1986;65(1):63-7. doi: 10.3109/00016348609158232.
The serum concentrations of the vitamin D metabolites 25-OHD, 1,25-(OH)2D, 24,25-(OH)2D and 25,26-(OH)2D, and of vitamin D binding protein (DBP), were determined longitudinally in 22 vitamin D supplemented pregnant women, and in 17 age-matched non-pregnant women studied during the summer. The pregnant women had higher 25-OHD and 1,25-(OH)2D, similar 24,25-(OH)2D, and lower 25,26-(OH)2D concentrations than the non-pregnant group. The relative concentrations of 24,25-(OH)2D and 25,26-(OH)2D (expressed as the molar ratio of these metabolites to 25-OHD) were lower during pregnancy. The DBP levels were increased in pregnancy, but the calculated free fraction (i.e. not bound to DBP) of the hormonal form of vitamin D, 1,25-(OH)2D, was still persistently higher in the pregnant than in the non-pregnant women. The study suggests that a daily vitamin D supplement of 400 IU satisfies the vitamin D requirement of pregnant women living in a cool climate with limited sun exposure. The increased absolute and relative concentration of 1,25-(OH)2D and decreased relative levels of 24,25-(OH)2D and 25,26-(OH)2D further suggest that the increased intestinal calcium and phosphate absorption, which is known to occur during pregnancy, is at least partially mediated by the vitamin D endocrine system.
对22名补充维生素D的孕妇以及17名年龄匹配的非孕妇（在夏季进行研究）的血清维生素D代谢物25-羟基维生素D（25-OHD）、1,25-二羟基维生素D（1,25-(OH)2D）、24,25-二羟基维生素D（24,25-(OH)2D）和25,26-二羟基维生素D（25,26-(OH)2D）以及维生素D结合蛋白（DBP）的浓度进行了纵向测定。与非孕妇组相比，孕妇的25-OHD和1,25-(OH)2D浓度较高，24,25-(OH)2D浓度相似，25,26-(OH)2D浓度较低。孕期24,25-(OH)2D和25,26-(OH)2D的相对浓度（以这些代谢物与25-OHD的摩尔比表示）较低。孕期DBP水平升高，但维生素D的激素形式1,25-(OH)2D的计算游离分数（即未与DBP结合的部分）在孕妇中仍持续高于非孕妇。该研究表明，每日补充400国际单位的维生素D可满足生活在凉爽气候且日照有限地区的孕妇对维生素D的需求。1,25-(OH)2D绝对和相对浓度的增加以及24,25-(OH)2D和25,26-(OH)2D相对水平的降低进一步表明，孕期已知发生的肠道钙和磷吸收增加至少部分由维生素D内分泌系统介导。
