Vitamin D deficiency has been widely reported among pregnant women and infants around the world. Women with low sun exposure, high BMI, low vitamin D intakes and socioeconomic disadvantage with poor quality diets are at greatest risk of vitamin D deficiency, leading to very low serum concentrations of 25-hydroxyvitamin D (25(OH)D) in their offspring and an increased risk of nutritional rickets. Many observational studies, supported by compelling in vitro and in vivo data, have generated evidence suggesting that low vitamin D status in pregnancy may also contribute to the risk of adverse perinatal outcomes including hypertensive disorders (e.g., preeclampsia), fetal growth restriction, and preterm birth. However, the few large randomized controlled trials (RCTs) conducted to date have generated conflicting evidence for a role of vitamin D supplementation in improving perinatal outcomes. Vitamin D supplementation policies during pregnancy and implementation of policies vary within and between jurisdictions. Regulatory authorities have cited insufficient evidence to establish pregnancy-specific targets for serum 25(OH)D concentrations or prenatal vitamin D intake that effectively reduce the risks of adverse perinatal and infant outcomes. This paper arises from a Debate on Vitamin D Requirements during Pregnancy, held at the 22nd Vitamin D Workshop, 2019. From varied perspectives, our objectives were to evaluate the evidence for: vitamin D metabolism in pregnancy and the prevalence of gestational vitamin D deficiency worldwide; the translation of laboratory research findings to clinical studies on the role of vitamin D in perinatal health; the challenges of designing and conducting clinical trials to establish prenatal vitamin D requirements; and results to date of major large RCTs of prenatal vitamin D supplementation. Lastly, we explored potential next steps towards generating robust clinical data in this field to address both public health protection and patient care.

中文翻译：

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怀孕期间的维生素D：我们在哪里以及应该去哪里。

维生素D缺乏症已在世界各地的孕妇和婴儿中广泛报道。低日光照射，高BMI，低维生素D摄入量以及不良饮食习惯对社会经济造成不利影响的妇女面临维生素D缺乏症的最大风险，从而导致其子代的血清中25-羟基维生素D（25（OH）D）的浓度非常低以及增加营养性increased病的风险。许多观察性研究都得到了令人信服的体外和体内数据的支持，这些证据表明，维生素D含量过低可能会增加围产期不良结局的风险，包括高血压疾病（例如先兆子痫），胎儿生长受限和早产出生。然而，迄今为止进行的几项大型随机对照试验（RCT）产生了相互矛盾的证据，证明补充维生素D在改善围产期结局中的作用。怀孕期间的维生素D补充政策以及政策的实施在各辖区内和辖区之间有所不同。监管机构援引的证据不足，无法针对血清25（OH）D浓度或产前维生素D摄入量确定怀孕特定目标，从而有效降低围产期和婴儿不良结局的风险。本文来自于2019年在第22届维生素D研讨会上举行的关于怀孕期间维生素D需求的辩论。从不同的角度来看，我们的目标是评估以下证据：怀孕期间的维生素D代谢和全球妊娠期维生素D缺乏症的流行; 将实验室研究结果转化为有关维生素D在围产期健康中的作用的临床研究；设计和进行临床试验以确定产前维生素D需求的挑战；以及迄今为止主要的产前补充维生素D的大型RCT。最后，我们探索了在该领域生成可靠的临床数据以解决公共卫生保护和患者护理的潜在下一步措施。