Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520-8064, USA.
Am J Clin Nutr. 2012 Jan;95(1):137-46. doi: 10.3945/ajcn.111.018721. Epub 2011 Dec 14.
Reports of clinical rickets are particularly evident in minority infants and children, but only limited analyses of vitamin D are available in this demographic group.
We sought to characterize circulating 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)(2)D], and their determinants, including circulating parathyroid hormone (PTH), total alkaline phosphatase activity (ALP), calcium, and phosphorus, in minority infants and children.
We obtained demographic information and blood samples for measurement of PTH, ALP, 25(OH)D, and 1,25(OH)(2)D in >750 6-mo- to 3-y-old children. Dietary intake data were obtained and analyzed.
The mean (±SD) 25(OH)D concentration was 66 ± 22 nmol/L (26.3 ± 8.7 ng/dL). A total of 15% of children had 25(OH)D concentrations less than the recommended target threshold of 50 nmol/L. Combined elevations of PTH and ALP occurred in only 2.5% of children. Determinants of 25(OH)D included vitamin D intake, age (decreasing with age), skin type (greater concentrations in lighter-skinned children than in darker-skinned children), formula use (higher intakes), season (greater concentrations in the summer and fall than in the winter and spring), and, inversely, PTH. The mean 1,25(OH)(2)D concentration was 158 ± 58 pmol/L (60.6 ± 22.5 pg/mL), which was consistent with a reference range of 41-274 pmol/L or 15.7-105.5 pg/mL. Determinants for 1,25(OH)(2)D were age (decreasing with age), sex (greater concentrations in girls than in boys), skin type (greater concentrations in lighter-skinned children than in darker-skinned children), and, inversely, serum calcium and phosphorus.
Although 15% of subjects were vitamin D insufficient, only 2.5% of subjects had elevations of both PTH and ALP. The greater 25(OH)D concentrations observed with formula use confirm that dietary vitamin D fortification is effective in this demographic group. Circulating 1,25(OH)(2)D is higher in infants than in older children and adults and, in contrast to 25(OH)D, is not directly correlated with nutrient intakes.
临床佝偻病的报告在少数民族婴儿和儿童中尤为明显，但在这一人群中，仅有有限的维生素 D 分析报告。
我们旨在描述少数民族婴儿和儿童的循环 25-羟维生素 D [25(OH)D]、1,25-二羟维生素 D [1,25(OH)(2)D]及其决定因素，包括循环甲状旁腺激素 (PTH)、总碱性磷酸酶活性 (ALP)、钙和磷。
我们收集了 750 多名 6 个月至 3 岁儿童的人口统计学信息和血液样本，用于测量 PTH、ALP、25(OH)D 和 1,25(OH)(2)D。我们还获取了饮食摄入数据并进行了分析。
25(OH)D 浓度的平均值（±SD）为 66 ± 22 nmol/L（26.3 ± 8.7 ng/dL）。15%的儿童 25(OH)D 浓度低于 50 nmol/L 的推荐目标阈值。只有 2.5%的儿童同时出现 PTH 和 ALP 升高。25(OH)D 的决定因素包括维生素 D 摄入量、年龄（随年龄增长而降低）、皮肤类型（浅色皮肤儿童的浓度高于深色皮肤儿童）、配方奶使用（摄入量较高）、季节（夏季和秋季的浓度高于冬季和春季），以及相反的甲状旁腺激素。1,25(OH)(2)D 的平均浓度为 158 ± 58 pmol/L（60.6 ± 22.5 pg/mL），与 41-274 pmol/L 或 15.7-105.5 pg/mL 的参考范围一致。1,25(OH)(2)D 的决定因素为年龄（随年龄增长而降低）、性别（女孩的浓度高于男孩）、皮肤类型（浅色皮肤儿童的浓度高于深色皮肤儿童），以及相反的血清钙和磷。
尽管 15%的受试者维生素 D 不足，但只有 2.5%的受试者同时出现 PTH 和 ALP 升高。在使用配方奶的情况下观察到更高的 25(OH)D 浓度证实了膳食维生素 D 强化在这一人群中是有效的。与 25(OH)D 不同，循环 1,25(OH)(2)D 在婴儿中高于在较大儿童和成人中，并且与营养素摄入量没有直接相关性。
