Debier Cathy
Institut des Sciences de la Vie, Unité de Biochimie de la Nutrition, Université Catholique de Louvain, Croix du Sud 2/8, B-1348 Louvain-la-Neuve, Belgium.
Vitam Horm. 2007;76:357-73. doi: 10.1016/S0083-6729(07)76013-2.
Vitamin E is a fat-soluble nutrient that is extremely important during the early stages of life, from the time of conception to the postnatal development of the infant. The mechanisms involved in its placental and mammary uptake appear to be allowed by the presence of lipoprotein receptors (LDL-receptor, VLDL-receptor, scavenger receptor class B type I) together with lipoprotein lipase at the placental and mammary barriers. In addition, alpha-tocopherol transfer protein has been described as playing an essential role in the selective transfer of RRR-alpha-tocopherol across the placenta. Lower alpha-tocopherol concentrations are found in cord blood as compared to maternal circulation. The ingestion of colostrum which contains very high levels of vitamin E is therefore of utmost importance to supply the newborn with an essential defense against oxygen toxicity. Pregnancy is sometimes associated with complications that may lead to a premature delivery of the baby. Preterm infants are usually facing an oxidative stress that is among others related to a deficiency in alpha-tocopherol, as it accumulates mainly during the third trimester of pregnancy. Despite vitamin E supplementation, preterm infants usually require significantly longer to replenish their serum alpha-tocopherol levels than full-term infants. The use of vitamin E as a therapeutic agent in preeclampsia, which induces high maternal and fetal morbidity and mortality, has been discussed in numerous papers. This disorder is indeed associated with an important oxidative stress in the placenta and maternal circulation. However, the most recent studies did not show a beneficial effect of vitamin E administration in this pathology.
维生素E是一种脂溶性营养素，在生命早期阶段，从受孕到婴儿出生后的发育过程中都极其重要。其通过胎盘和乳腺摄取的机制似乎是由于胎盘和乳腺屏障处存在脂蛋白受体（低密度脂蛋白受体、极低密度脂蛋白受体、I型清道夫受体B类）以及脂蛋白脂肪酶。此外，α-生育酚转运蛋白被认为在RRR-α-生育酚跨胎盘的选择性转运中起着至关重要的作用。与母体循环相比，脐带血中的α-生育酚浓度较低。因此，摄入含有极高水平维生素E的初乳对于为新生儿提供抵御氧毒性的重要防御至关重要。妊娠有时会伴有一些并发症，可能导致婴儿早产。早产儿通常面临氧化应激，这尤其与α-生育酚缺乏有关，因为它主要在妊娠晚期积累。尽管补充了维生素E，但早产儿补充血清α-生育酚水平通常比足月儿需要更长的时间。许多论文都讨论了将维生素E用作子痫前期治疗药物的情况，子痫前期会导致高孕产妇和胎儿发病率及死亡率。这种疾病确实与胎盘和母体循环中的重要氧化应激有关。然而，最近的研究并未显示维生素E给药对这种病症有有益效果。
