Department of Physiology, University of Murcia, Biomedical Research Institute of Murcia (IMIB-Arrixaca), Murcia, Spain.
IMIB-Arrixaca, Department of Public Health Sciences, University of Murcia, CIBER en Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.
Ann Nutr Metab. 2018;72(3):179-192. doi: 10.1159/000487370. Epub 2018 Mar 13.
To what extent does the circulating 25-hydroxyvitamin D (25[OH]D) concentration help to meet the physiological needs of humans is an ongoing subject of debate. Remaining unexposed to the sun to reduce melanoma cancer risk, current lifestyle with less out door activities, and increasing obesity rates, which in turn increases the storage of vitamin D in the adipose tissue, are presumably factors that contribute to the substantial upsurge in the prevalence of vitamin D deficiency in humans. Since evidence is lacking regarding the appropriate cut-off points to define vitamin D status during pregnancy, references used to establish the intake recommendations and vitamin D content of prenatal vitamin supplements are quite conservative.
The foetus depends fully on maternal 25(OH)D supply. 25(OH)D readily crosses the placenta and it is activated into 1,25(OH)2D by foetal kidneys. Moreover, 1,25(OH)2D can also be synthesized within the placenta to regulate placental metabolism. The importance of vitamin D during pregnancy for maintaining maternal calcium homeostasis and therefore for foetal bone development is well recognized; major discussions are in progress regarding the potential maternal detrimental effects on pregnancy outcomes, foetal development, and the long-term health of children. Interventional studies have also evaluated the effect of vitamin D for reduction on preterm birth and asthma programming. Key Messages: Clinically, by understanding the effects of vitamin D on perinatal outcomes, we could individualize antenatal counselling regarding vitamin D supplementation to ensure vitamin D repletion without increasing the risk of foetal hypercalcemia.
循环 25-羟维生素 D（25[OH]D）浓度在多大程度上有助于满足人体的生理需求，这是一个持续存在的争议话题。为了降低黑色素瘤癌症风险而避免阳光照射、户外活动减少的当前生活方式，以及肥胖率的上升，这反过来又增加了维生素 D 在脂肪组织中的储存，这些因素可能导致人类维生素 D 缺乏症的患病率大幅上升。由于缺乏关于怀孕期间定义维生素 D 状态的适当切点的证据，因此用于确定摄入建议和产前维生素补充剂中维生素 D 含量的参考依据相当保守。
胎儿完全依赖于母体 25（OH）D 的供应。25（OH）D 很容易穿过胎盘，并且在胎儿肾脏中被激活为 1,25（OH）2D。此外，胎盘内也可以合成 1,25（OH）2D 以调节胎盘代谢。怀孕期间维生素 D 对于维持母体钙稳态从而促进胎儿骨骼发育的重要性已得到充分认识；关于维生素 D 对妊娠结局、胎儿发育和儿童长期健康的潜在母体不良影响的讨论正在进行中。干预性研究还评估了维生素 D 对降低早产和哮喘发病的影响。
临床上，通过了解维生素 D 对围产期结局的影响，我们可以针对个体进行产前咨询，进行维生素 D 补充，以确保维生素 D 得到补充，而不会增加胎儿高钙血症的风险。
