Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
Am J Clin Nutr. 2012 May;95(5):1103-12. doi: 10.3945/ajcn.111.023861. Epub 2012 Apr 4.
Maternal calcium intake and vitamin D status may affect fetal bone development.
This study was designed to examine relations between maternal calcium intake, 25-hydroxyvitamin D [25(OH)D] status, and fetal bone growth across pregnancy.
This was a prospective longitudinal design. Maternal 25(OH)D, parathyroid hormone, and 1,25-dihydroxyvitamin D [1,25(OH)(2)D] were determined at midgestation (∼26 wk) and at delivery in 171 adolescents (≤ 18 y). Dietary recalls and fetal sonograms were performed up to 3 times across gestation, and fetal femur and humerus z scores were generated.
Fetal femur and humerus z scores and neonatal birth length were significantly greater (P < 0.03) in adolescents consuming ≥ 1050 mg than in those consuming <1050 mg Ca/d. Maternal 25(OH)D > 50 nmol/L was significantly positively associated with fetal femur and humerus z scores (P < 0.01). When maternal smoking, height, race, weight gain, and gestational age were controlled for, these relations remained significant. Interactions between calcium intake and 25(OH)D were evident. Calcium intake was associated with fetal femur z scores and birth length only when maternal 25(OH)D was ≤ 50 nmol/L (P < 0.05). Similarly, maternal 25(OH)D was associated with fetal femur and humerus z scores only when maternal calcium intake was <1050 mg/d (P < 0.03).
Optimal calcium intake and adequate maternal vitamin D status are both needed to maximize fetal bone growth. Interactions between these nutrients were evident when either calcium or vitamin D status was limited. Improving maternal calcium intake and/or vitamin D status during pregnancy may have a positive effect on fetal skeletal development in pregnant adolescents.
母体钙摄入量和维生素 D 状况可能会影响胎儿的骨骼发育。
本研究旨在探讨妊娠期间母体钙摄入量、25-羟维生素 D [25(OH)D]状况与胎儿骨骼生长之间的关系。
这是一项前瞻性纵向设计。在 171 名青少年（≤ 18 岁）妊娠中期（约 26 周）和分娩时测定了母体 25(OH)D、甲状旁腺激素和 1,25-二羟维生素 D [1,25(OH)(2)D]。在妊娠期间进行了多达 3 次的饮食回顾和胎儿超声检查，并生成了胎儿股骨和肱骨 z 评分。
摄入≥1050mg 钙的青少年的胎儿股骨和肱骨 z 评分以及新生儿出生长度显著更大（P<0.03）。母体 25(OH)D>50nmol/L 与胎儿股骨和肱骨 z 评分显著正相关（P<0.01）。当控制母体吸烟、身高、种族、体重增加和胎龄时，这些关系仍然显著。钙摄入量和 25(OH)D 之间存在相互作用。只有当母体 25(OH)D≤50nmol/L 时，钙摄入量才与胎儿股骨 z 评分和出生长度相关（P<0.05）。同样，只有当母体钙摄入量<1050mg/d 时，母体 25(OH)D 才与胎儿股骨和肱骨 z 评分相关（P<0.03）。
要使胎儿骨骼生长最大化，需要摄入最佳的钙量和足够的母体维生素 D 状态。当任一营养素的状况受到限制时，这些营养素之间存在相互作用。在妊娠期间改善母体钙摄入量和/或维生素 D 状态可能对妊娠青少年胎儿骨骼发育产生积极影响。
