Department of Food and Nutritional Sciences, University College, Cork, Ireland.
J Nutr. 2010 Mar;140(3):454-60. doi: 10.3945/jn.109.113480. Epub 2010 Jan 20.
Although there have been several studies of the effect of vitamin D status on bone turnover in the elderly, the findings are unclear, and, furthermore, to date very few have investigated this in young adults. The objective of these randomized, placebo-controlled, double-blind, 2-center intervention studies was to investigate the effect of cholecalciferol supplementation (0, 5, 10, and 15 microg cholecalciferol/d) throughout winter time on indices of vitamin D status and bone turnover in young (aged 20-40 y; n = 215) and elderly (aged > or = 64 y; n = 204) adults, with relatively high mean calcium intakes of 976 and 874 mg/d, respectively. Fasting serum concentrations of 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), osteocalcin, bone-specific alkaline phosphatase, and carboxyterminal collagen crosslinks were measured by enzyme immunoassays at baseline and endpoint. Fok I and Taq I vitamin D receptor (VDR) genotypes were determined by real-time PCR. Endpoint serum 25(OH)D increased (P < 0.0001) in a dose-related manner with increasing supplemental cholecalciferol (up to 15 microg/d) in 20-40-y olds and up to 10 microg/d in > or = 64-y olds. Endpoint serum PTH was lower (P < 0.05) in the 3 cholecalciferol-supplemented groups compared with that in the placebo group in > or = 64-y olds, but cholecalciferol supplementation did not affect other markers in either cohort and there was no significant interaction with VDR genotype. In conclusion, cholecalciferol supplementation alone throughout winter did not affect bone turnover markers in apparently healthy young and elderly adults, even when stratified by VDR genotype.
尽管已经有几项关于维生素 D 状态对老年人骨转换影响的研究，但研究结果并不明确，而且迄今为止，很少有研究调查年轻人的情况。这些随机、安慰剂对照、双盲、2 中心干预研究的目的是研究在冬季补充胆钙化醇（0、5、10 和 15 微克胆钙化醇/天）对年轻（年龄 20-40 岁；n=215）和老年（年龄≥64 岁；n=204）成年人维生素 D 状态和骨转换的影响，他们的平均钙摄入量分别为 976 和 874mg/d。空腹血清 25-羟维生素 D [25(OH)D]、甲状旁腺激素 (PTH)、骨钙素、骨碱性磷酸酶和羧基末端胶原交联的浓度通过酶联免疫吸附试验在基线和终点进行测量。Fok I 和 Taq I 维生素 D 受体 (VDR) 基因型通过实时 PCR 确定。在 20-40 岁的年轻人中，随着补充胆钙化醇剂量的增加（最高 15 微克/天），终点血清 25(OH)D 呈剂量相关增加（P<0.0001），而在≥64 岁的老年人中，最高增加至 10 微克/天。与安慰剂组相比，在≥64 岁的老年人中，补充胆钙化醇的 3 个组的终点血清 PTH 较低（P<0.05），但胆钙化醇补充剂并没有影响两个队列中的其他标志物，也与 VDR 基因型没有明显的相互作用。总之，在冬季单独补充胆钙化醇不会影响明显健康的年轻和老年成年人的骨转换标志物，即使按 VDR 基因型分层也是如此。
