Koo W W, Sherman R, Succop P, Ho M, Buckley D, Tsang R C
Department of Pediatrics, University of Cincinnati, Children's Hospital Research Foundation, Ohio.
J Pediatr. 1989 Jun;114(6):1017-22. doi: 10.1016/s0022-3476(89)80455-x.
Seventy-one very low birth weight (less than or equal to 1500 gm) infants were studied to determine the sequential changes in serum vitamin D metabolite concentrations between infants with and without radiographically documented rickets, fractures, or both (R/F). Usual intake of vitamin D included 20 IU/kg/day from parenteral nutrition or 400 IU/day supplementation with enteral feeding. Radiographs of both forearms and serum samples were obtained at 3, 6, 9, and 12 months. Twenty-two infants had R/F. At 3 months, significantly lower mean (+/- SEM) serum phosphorus levels (4.5 +/- 0.4 vs 6.1 +/- 0.2 mg/dl), higher 1,25-dihydroxyvitamin D (1,25-[OH]2D) concentrations (96 +/- 5 vs 77 +/- 4 pg/ml), and higher free 1,25-(OH)2D index (1,25-[OH]2D:vitamin D binding protein ratio; 5.2 +/- 0.3 x 10(5) vs 4.0 +/- 0.2 x 10(5] were found in the R/F group. These values returned to normal and were similar between groups on subsequent measurements. Serum calcium, magnesium, and 25-hydroxyvitamin D (25-OHD) concentrations were normal and similar between groups. In both groups, serum vitamin D binding concentrations increased initially but remained stable and normal beyond 6 months. We conclude that in very low birth weight infants with R/F, the vitamin D status (as indicated by serum 25-OHD concentrations) is normal, and that lowered serum phosphorus levels, higher serum 1,25-(OH)2D levels, and a higher free 1,25-(OH)2D index support the thesis that mineral deficiency (especially of phosphorus) may be important in the pathogenesis of R/F in small preterm infants.
对71名极低出生体重（小于或等于1500克）的婴儿进行了研究，以确定有或没有影像学记录的佝偻病、骨折或两者兼具（R/F）的婴儿血清维生素D代谢物浓度的连续变化。维生素D的常规摄入量包括肠外营养中20 IU/kg/天或肠内喂养时补充400 IU/天。在3、6、9和12个月时获取双前臂X线片和血清样本。22名婴儿患有R/F。在3个月时，R/F组的平均（±标准误）血清磷水平显著较低（4.5±0.4 vs 6.1±0.2 mg/dl），1,25-二羟维生素D（1,25-[OH]2D）浓度较高（96±5 vs 77±4 pg/ml），游离1,25-(OH)2D指数较高（1,25-[OH]2D：维生素D结合蛋白比值；5.2±0.3×10(5) vs 4.0±0.2×10(5]）。在随后的测量中，这些值恢复正常且两组之间相似。血清钙、镁和25-羟维生素D（25-OHD）浓度正常且两组之间相似。在两组中，血清维生素D结合浓度最初升高，但6个月后保持稳定且正常。我们得出结论，在患有R/F的极低出生体重婴儿中，维生素D状态（以血清25-OHD浓度表示）正常，血清磷水平降低、血清1,25-(OH)2D水平升高以及游离1,25-(OH)2D指数升高支持矿物质缺乏（尤其是磷缺乏）可能在小早产儿R/F发病机制中起重要作用这一论点。
