New insights into the vitamin D requirements during pregnancy

作     者：Bruce W Hollis Carol L Wagner 

作者机构：Department of Pediatrics Darby Children's Research Institute Medical University of South Carolina 

出 版 物：《Bone Research》 (骨研究（英文版）)

年 卷 期：2017年第5卷第3期

页      面：161-176页

核心收录：

学科分类：1004[医学-公共卫生与预防医学(可授医学、理学学位)] 10[医学] 

基　　金：Funded in part by NIH/NICHD R01 HD043921 the Thrasher Research Fund NIH/NCATS UL1 RR029882 UL1 TR000062 

主　　题：New insights into the vitamin D requirements during pregnancy 

摘      要：Pregnancy represents a dynamic period with physical and physiological changes in both the mother and her developing fetus. The dramatic 2-3 fold increase in the active hormone 1,25（OH）2D concentrations during the early weeks of pregnancy despite minimal increased calcium demands during that time of gestation and which are sustained throughout pregnancy in both the mother and fetus suggests an immunomodulatory role in preventing fetal rejection by the mother. While there have been numerous observational studies that support the premise of vitamin D＇s role in maintaining maternal and fetal well-being, until recently, there have been few randomized clinical trials with vitamin D supplementation. One has to exhibit caution, however, even with RCTs, whose results can be problematic when analyzed on an intent-to-treat basis and when there is high non-adherence to protocol （as if often the case）, thereby diluting the potential good or harm of a given treatment at higher doses. As such, a biomarker of a drug or in this case ＂vitamin＂ or pre-prohormone is better served. For these reasons, the effect of vitamin D therapies using the biomarker circulating 25（OH）D is a far better indicator of true ＂effect.＂ When pregnancy outcomes are analyzed using the biomarker 25（OH）D instead of treatment dose, there are notable differences in maternal and fetal outcomes across diverse racial/ethnic groups, with improved health in those women who attain a circulating 25（OH）D concentration of at least 100 nmol. L-1 （40 ng. mL-1）. Because ,an important issue is the timing or initiation of vitamin D treatment/supplementation, and given the potential effect of vitamin D on placental gene expression and its effects on inflammation within the placenta, it appears crucial to start vitamin D treatment before placentation （and trophoblast invasion）; however, this question remains unanswered. Additional work is needed to decipher the vitamin D requirements of pregnant women and the optimal timing of s