BACKGROUND Severe vitamin D deficiency causes osteomalacia, yet trials of vitamin D supplementation in the community have not on average demonstrated benefit to bone mineral density (BMD) or fracture risk in adults. OBJECTIVE To determine whether monthly high-dose vitamin D supplementation influences BMD in the general population and in those with low 25-hydroxyvitamin D levels. METHODS Two-year substudy of a trial in older community-resident adults. A total of 452 participants were randomized to receive monthly doses of vitamin D3 100 000 IU, or placebo. The primary end-point was change in lumbar spine BMD. Exploratory analyses to identify thresholds of baseline 25-hydroxyvitamin D for vitamin D effects on BMD were prespecified. RESULTS Intention-to-treat analyses showed no significant treatment effect in the lumbar spine (between-groups difference 0.0071 g cm-2 , 95%CI: -0.0012, 0.0154) or total body but BMD loss at both hip sites was significantly attenuated by ~1/2% over 2 years. There was a significant interaction between baseline 25-hydroxyvitamin D and treatment effect (P = 0.04). With baseline 25-hydroxyvitamin D ≤ 30 nmol L-1 (n = 46), there were between-groups BMD changes at the spine and femoral sites of ~2%, significant in the spine and femoral neck, but there was no effect on total body BMD. When baseline 25-hydroxyvitamin D was >30 nmol L-1 , differences were ~1/2% and significant only at the total hip. CONCLUSIONS This substudy finds no clinically important benefit to BMD from untargeted vitamin D supplementation of older, community-dwelling adults. Exploratory analyses suggest meaningful benefit in those with baseline 25-hydroxyvitamin D ≤ 30 nmol L-1 . This represents a significant step towards a trial-based definition of vitamin D deficiency for bone health in older adults.

中文翻译：

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一项随机对照试验的结果显示，每月高剂量维生素D对社区老年人的骨密度的影响。

背景技术严重的维生素D缺乏症会导致骨软化症，但是在社区中补充维生素D的试验平均没有证明对成年人的骨矿物质密度（BMD）或骨折风险有益。目的确定每月大剂量补充维生素D是否会影响普通人群和25-羟维生素D水平低的人群的BMD。方法对居住在社区的老年人进行为期两年的研究。总共452名参与者被随机分配接受每月剂量100 000 IU的维生素D3或安慰剂。主要终点是腰椎骨密度的变化。预先进行了探索性分析，以确定基线25-羟基维生素D对维生素D对BMD的影响的阈值。结果意向性治疗分析未显示出对腰椎（组间差异0.0071 g cm-2，95％CI：-0.0012、0.0154）或全身的显着治疗效果，但两个髋部的BMD损失均显着减轻了2年内〜1/2％。基线25-羟基维生素D与治疗效果之间存在显着的相互作用（P = 0.04）。在基线25-羟基维生素D≤30 nmol L-1（n = 46）的情况下，两组之间在脊柱和股骨处的BMD变化约为2％，在脊柱和股骨颈处显着，但对全身骨密度。当基线25-羟基维生素D> 30 nmol L-1时，差异为〜1/2％，仅在整个髋关节处显着。结论：这项研究没有发现年龄较大，居住在社区的成年人无针对性地补充维生素D对BMD没有重要的临床意义。探索性分析表明，基线25-羟基维生素D≤30 nmol L-1的患者获益匪浅。这是朝着基于试验确定老年人骨骼健康中维生素D缺乏症迈出的重要一步。