Background Vitamin D, acknowledged since the 1930s for its role in preventing rickets, gained additional prominence in relation to fragility fracture prevention in the late 1980s. From the early 2000s, connections between vitamin D deficiency and extra-skeletal pathologies emerged, alongside increased awareness of widespread deficits. This prompted crucial debates on optimal serum concentrations, expected to conclude when the outcomes of high-dose supplementation randomized controlled trials were available. Skepticism arose with inconclusive results from these trials. Content This review begins with an exploration of vitamin D metabolism, followed by a detailed description of the measurement of vitamin D metabolites and the crucial role of standardization. Subsequent sections focus on the association of vitamin D with bone health and explore the extra-skeletal effects. The review concludes with a comprehensive discussion on the definition of vitamin D status and its implications for supplementation. Summary Despite standardization efforts, assay variations and challenges still exist, especially in specific patient groups. Vitamin D supplementation has a significant impact on bone metabolism and optimal vitamin D status improves the efficacy of antiresorptive drugs such as bisphosphonates. The extra-skeletal effects of vitamin D remain debated, but may include potential benefits in conditions such as respiratory infections and cancer mortality, particularly in deficient individuals. The definition of vitamin D sufficiency is nuanced, especially when variations in population groups and analytical methods are taken into account. Despite ongoing debates and recent mega-trials tempering enthusiasm, vitamin D remains a complex and essential element in human health. Further research is needed to clarify its role in various health outcomes and guide supplementation strategies.

中文翻译：

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维生素 D：分析进展、临床影响以及关于健康观点的持续争论

背景 维生素 D 自 20 世纪 30 年代以来因其在预防佝偻病方面的作用而得到认可，在 20 世纪 80 年代末期在预防脆性骨折方面获得了进一步的重视。从 2000 年代初期开始，维生素 D 缺乏症与骨骼外疾病之间的联系开始显现，同时人们对普遍缺乏维生素 D 的认识也有所提高。这引发了关于最佳血清浓度的关键争论，预计当高剂量补充剂随机对照试验的结果出来时就会得出结论。这些试验的不确定结果引发了怀疑。内容 本综述首先探讨维生素 D 代谢，然后详细描述维生素 D 代谢物的测量以及标准化的关键作用。后续部分重点介绍维生素 D 与骨骼健康的关系，并探讨骨骼外的影响。该综述最后对维生素 D 状态的定义及其对补充的影响进行了全面讨论。总结 尽管进行了标准化工作，但检测方法的差异和挑战仍然存在，特别是在特定的患者群体中。补充维生素 D 对骨代谢具有显着影响，最佳维生素 D 状态可提高双磷酸盐等抗骨吸收药物的疗效。维生素 D 的骨骼外作用仍存在争议，但可能包括对呼吸道感染和癌症死亡率等疾病的潜在益处，特别是对于缺乏维生素 D 的个体。维生素 D 充足性的定义是微妙的，特别是考虑到人群和分析方法的差异时。尽管持续的争论和最近的大型试验削弱了人们的热情，但维生素 D 仍然是人类健康中复杂而重要的元素。需要进一步的研究来阐明其在各种健康结果中的作用并指导补充策略。