BACKGROUND The rationale for the prescription of vitamin D analogues in patients with chronic kidney disease (CKD) is still a matter of debate. We aimed to compare native vs. active forms of vitamin D on pre-dialysis children with CKD and evaluate effects on calcium (Ca), phosphorus (P), and parathyroid hormone (PTH). METHODS Thirty children with pre-dialysis CKD were enrolled in a prospective cross-over study. Patients were randomly classified into two groups. Group A received native cholecalciferol while group B received alfacalcidol for 3 months. After 1 month (washout period), patients were switched to receive the opposite form for another 3 months. Serum Ca, P, alkaline phosphatase (ALP), PTH, and 25(OH)D3 were measured at study start (BL-1), end of first period (FU-1), before second period (BL-2), and after second period (FU-2). RESULTS There was significant increase in levels of 25(OH)D3 after administration of either native or active vitamin D in the first period in both groups (p < 0.001 and < 0.001, respectively) and also in the second period for both groups (p = 0.02 and < 0.001, respectively). There was no significant difference between both groups regarding changes in serum Ca (1st period; p = 0.770 and 2nd period; p = 0.412), serum P (1st period; p = 0.835, 2nd period; p = 0.052), and serum PTH (1st period; p = 0.250, 2nd period; p = 0.539). CONCLUSION Alfacalcidol and native vitamin D3 were equally effective in decreasing PTH levels and increasing serum 25(OH)D3 in pre-dialysis CKD patients. There was no significant difference between the two forms regarding changes in serum Ca or P. Graphical abstract.

中文翻译：

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慢性肾病儿童的天然维生素 D 与活性维生素 D：交叉研究。

背景 在慢性肾病 (CKD) 患者中开具维生素 D 类似物处方的基本原理仍然存在争议。我们旨在比较天然与活性形式的维生素 D 对透析前 CKD 儿童的影响，并评估对钙 (Ca)、磷 (P) 和甲状旁腺激素 (PTH) 的影响。方法 30 名患有透析前 CKD 的儿童参加了一项前瞻性交叉研究。患者被随机分为两组。A 组接受天然胆钙化醇，B 组接受阿法骨化醇治疗 3 个月。1 个月后（洗脱期），患者转而接受另一种形式的治疗，为期 3 个月。血清 Ca、P、碱性磷酸酶 (ALP)、PTH 和 25(OH)D3 在研究开始 (BL-1)、第一阶段结束 (FU-1)、第二阶段之前 (BL-2) 和在第二阶段（FU-2）之后。结果 两组的第一阶段（分别为 p < 0.001 和 < 0.001）和第二阶段（p = 0.02 和 < 0.001，分别）。两组之间在血清 Ca（第一期；p = 0.770 和第二期；p = 0.412）、血清 P（第一期；p = 0.835，第二期；p = 0.052）和血清 PTH 的变化方面没有显着差异（第一期；p = 0.250，第二期；p = 0.539）。结论 阿法骨化醇和天然维生素 D3 在降低透析前 CKD 患者的 PTH 水平和增加血清 25(OH)D3 方面同样有效。两种形式在血清 Ca 或 P 的变化方面没有显着差异。图形摘要。