Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany; Center for Cardiovascular Research, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany; Department of Biochemistry, Faculty of Pharmacy, Zagazig University, Egypt.
J Steroid Biochem Mol Biol. 2018 Jun;180:51-64. doi: 10.1016/j.jsbmb.2017.11.008. Epub 2017 Nov 21.
Observational studies from all over the world continue to find high prevalence rates of vitamin D insufficiency and deficiency in many populations, including pregnant women. Beyond its classical function as a regulator of calcium and phosphate metabolism, vitamin D elicits numerous effects in the human body. Current evidence highlights a vital role of vitamin D in mammalian gestation. During pregnancy, adaptations in maternal vitamin D metabolism lead to a physiologic increase of vitamin D levels, mainly because of an increased renal production, although other potential sources like the placenta are being discussed. A sufficient supply of mother and child with calcium and vitamin D during pregnancy ensures a healthy bone development of the fetus, whereas lack of either of these nutrients can lead to the development of rickets in the child. Moreover, vitamin D insufficiency during pregnancy has consistently been associated with adverse maternal and neonatal pregnancy outcomes. In multitudinous studies, low maternal vitamin D status was associated with a higher risk for preeclampsia, gestational diabetes mellitus and other gestational diseases. Likewise, several negative consequences for the fetus have been reported, including fetal growth restriction, increased risk of preterm birth and a changed susceptibility for later-life diseases. However, study results are diverging and causality has not been proven so far. Meta-analyses on the relationship between maternal vitamin D status and pregnancy outcomes revealed a wide heterogeneity of studied populations and the applied methodology in vitamin D assessment. Until today, clinical guidelines for supplementation cannot be based on high-quality evidence and it is not clear if the required intake for pregnant women differs from non-pregnant women. Long-term safety data of vitamin D supplementation in pregnant women has not been established and overdosing of vitamin D might have unfavorable effects, especially in mothers and newborns with mutations of genes involved in vitamin D metabolism. Reliable data from large observational and interventional randomized control trials are urgently needed as a basis for any detailed and safe recommendations for supplementation in the general population and, most importantly, in pregnant women. This is of utmost importance, as ensuring a sufficient vitamin D-supply of mother and child implies a great potential for the prevention of birth complications and development of diseases.
来自世界各地的观察性研究继续在许多人群中发现维生素 D 不足和缺乏的高患病率，包括孕妇。除了作为钙和磷酸盐代谢调节剂的经典功能外，维生素 D 在人体中还产生许多作用。目前的证据强调了维生素 D 在哺乳动物妊娠中的重要作用。在怀孕期间，母体维生素 D 代谢的适应性导致维生素 D 水平的生理性增加，主要是由于肾脏产生增加，尽管正在讨论胎盘等其他潜在来源。孕妇和儿童充足的钙和维生素 D 供应可确保胎儿健康的骨骼发育，而缺乏这些营养素中的任何一种都可能导致儿童佝偻病的发展。此外，孕妇维生素 D 不足一直与不良的母婴妊娠结局相关。在众多研究中，母体维生素 D 状态较低与子痫前期、妊娠糖尿病和其他妊娠疾病的风险增加相关。同样，也有报道称胎儿存在多种负面后果，包括胎儿生长受限、早产风险增加以及以后生活中疾病的易感性改变。然而，研究结果存在差异，因果关系尚未得到证实。关于母体维生素 D 状态与妊娠结局之间关系的荟萃分析显示，研究人群和维生素 D 评估中应用的方法存在很大的异质性。直到今天，补充剂的临床指南都不能基于高质量的证据，也不清楚孕妇所需的摄入量是否与非孕妇不同。孕妇补充维生素 D 的长期安全性数据尚未建立，维生素 D 过量可能会产生不利影响，尤其是在涉及维生素 D 代谢的基因发生突变的母亲和新生儿中。迫切需要来自大型观察性和干预性随机对照试验的可靠数据，作为在一般人群中进行补充的详细和安全建议的基础，最重要的是在孕妇中。这一点至关重要，因为确保母亲和儿童获得充足的维生素 D 供应具有很大的预防出生并发症和疾病发展的潜力。
