Tabatabaei Negar, Rodd Celia J, Kremer Richard, Khavandgar Zohreh, Murshed Monzur, Weiler Hope A
School of Dietetics and Human Nutrition, McGill University, Ste-Anne-de-Bellevue, Canada;
Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada;
J Nutr. 2014 Dec;144(12):1985-93. doi: 10.3945/jn.114.197806. Epub 2014 Oct 15.
The effects of vitamin D during pregnancy on maternal and neonatal bone health remain unclear.
This study was designed to test whether dietary vitamin D dose-dependently affects maternal and neonatal bone health.
Female guinea pigs (n = 45; 4 mo old) were randomly assigned at mating to receive 1 of 5 doses of vitamin D3 (cholecalciferol; 0, 0.25, 0.5, 1, or 2 IU/g diet) throughout pregnancy. Plasma vitamin D metabolites, mineral homeostasis, bone biomarkers, and bone mass were tested in sows throughout pregnancy and in 2-d-old pups. Microarchitecture and histology of excised bone were conducted postpartum.
By 3 wk of pregnancy, plasma 25-hydroxyvitamin D [25(OH)D] followed a positive dose-response, whereas 1,25-dihydroxyvitamin D [1,25(OH)2D] reached a plateau if vitamin D was ≥0.5 IU/g diet. Weight gain, areal bone mineral density (aBMD), volumetic bone mineral density (vBMD), and bone biomarkers did not differ among maternal groups. A positive dose-response was observed for mean ± SEM pup plasma concentrations of 25(OH)D (10.5 ± 1.50 to 113 ±11.6 nmol/L) and 1,25(OH)2D (123 ± 13.8 to 544 ± 53.3 pmol/L). Pup weight, plasma minerals, and osteocalcin were not different; plasma deoxypyridinoline was lower in the 1- and 0.25-IU/g groups than in all other groups. Pup femur aBMD was higher (9.2-13%; P = 0.04) in the 2-IU/g group than in all other groups except for the 0-IU/g group. Tibia and femur vBMD of pups responded to maternal diet in a U-shaped pattern. The femoral growth plate was 7.9% wider in the 0-IU/g group than in the 1-IU/g group.
Maternal vitamin D supplementation dose-dependently altered pup long bone architecture and mineral density in a manner similar to vitamin D deficient rickets whereas maternal bone was stable. These data reinforce that inadequate maternal vitamin D intake may compromise neonatal bone health and that exceeding recommendations is not advantageous.
孕期维生素D对母体和新生儿骨骼健康的影响仍不明确。
本研究旨在测试膳食维生素D是否剂量依赖性地影响母体和新生儿骨骼健康。
雌性豚鼠（n = 45；4月龄）在交配时随机分组，在整个孕期接受5种剂量维生素D3（胆钙化醇）中的1种（0、0.25、0.5、1或2 IU/g饲料）。在整个孕期对母猪以及2日龄幼崽检测血浆维生素D代谢产物、矿物质稳态、骨生物标志物和骨量。产后对切除的骨骼进行微观结构和组织学检查。
怀孕3周时，血浆25-羟基维生素D [25(OH)D]呈正剂量反应，而如果维生素D≥0.5 IU/g饲料，1,25-二羟基维生素D [1,25(OH)2D]则达到平台期。母体各组间体重增加、面积骨矿物质密度（aBMD）、体积骨矿物质密度（vBMD）和骨生物标志物无差异。幼崽血浆25(OH)D（10.5±1.50至113±11.6 nmol/L）和1,25(OH)2D（123±13.8至544±53.3 pmol/L）的平均±标准误浓度呈正剂量反应。幼崽体重、血浆矿物质和骨钙素无差异；1 IU/g和0.25 IU/g组的血浆脱氧吡啶啉低于所有其他组。2 IU/g组幼崽股骨aBMD比除0 IU/g组外的所有其他组高（9.2 - 13%；P = 0.04）。幼崽胫骨和股骨的vBMD对母体饮食呈U形反应。0 IU/g组的股骨生长板比1 IU/g组宽7.9%。
母体补充维生素D剂量依赖性地改变幼崽长骨结构和矿物质密度，方式类似于维生素D缺乏性佝偻病，而母体骨骼保持稳定。这些数据强化了母体维生素D摄入不足可能损害新生儿骨骼健康，且超过推荐量并无益处的观点。
