Abrams Steven A
US Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA.
Am J Clin Nutr. 2007 Feb;85(2):604S-607S. doi: 10.1093/ajcn/85.2.604S.
Only limited aspects of the transfer of calcium across the placenta to the fetus are known. Clinical outcome studies suggest that bone mineral mass in newborn infants is related to maternal size and dairy intake. Available data indicate that vitamin D deficiency may also limit in utero fetal bone mineral accumulation. Recent data suggest that maternal vitamin D status affects long-term childhood bone status. At present, no strong evidence exists showing that improving maternal calcium or vitamin D status has a long-term positive effect on childhood bone mass. In premature infants, clinical rickets and fractures are common. In utero rates of calcium accretion during the third trimester cannot be readily achieved. The use of fortifiers designed for human-milk-fed infants or specially designed high-mineral-containing formulas allows for bone mineral accretion at or near in utero rates. Recent data have shown that physical therapy programs, judiciously used, in combination with adequate mineral content, can enhance bone mineral mass in preterm infants. There is little evidence for the use of high doses of vitamin D in the management of premature infants. After hospital discharge, continuation of a relatively high mineral intake has been shown to enhance bone mineral acquisition. Future research should include evaluations of the role of maternal vitamin D supplementation on fetal and infant bone mass, the mineral needs of infants weighing <800 g or <25 wk gestation, and the optimal discharge management of premature infants who are at risk of low bone mass.
目前已知的钙经胎盘向胎儿转运的方面有限。临床结局研究表明，新生儿的骨矿物质含量与母亲的体型和乳制品摄入量有关。现有数据表明，维生素D缺乏也可能限制子宫内胎儿骨矿物质的积累。最新数据表明，母亲的维生素D状况会影响儿童期的长期骨骼状况。目前，没有有力证据表明改善母亲的钙或维生素D状况对儿童期骨量有长期积极影响。在早产儿中，临床佝偻病和骨折很常见。妊娠晚期子宫内的钙积聚速率难以轻易实现。使用专为母乳喂养婴儿设计的强化剂或特别设计的高矿物质配方奶粉可使骨矿物质以接近子宫内的速率积聚。最新数据表明，合理使用物理治疗方案并结合充足的矿物质含量，可以提高早产儿的骨矿物质含量。几乎没有证据支持在早产儿管理中使用高剂量维生素D。出院后，持续摄入相对较高的矿物质已被证明可促进骨矿物质的获取。未来的研究应包括评估母亲补充维生素D对胎儿和婴儿骨量的作用、体重<800 g或孕周<25周的婴儿的矿物质需求，以及对有低骨量风险的早产儿的最佳出院管理。
