The main role of vitamin D is to control mineral homeostasis. However, recent studies suggested the existence of a number of extraskeletal effects. Among the latter, preclinical studies provided consistent data on the involvement of vitamin D in innate and adaptive immunity and autoimmunity. Molecular biology studies showed that both vitamin D receptor and vitamin D enzymatic complexes are expressed in a large number of cells and tissues unrelated to mineral homeostasis. In contrast, only a few randomized clinical trials in humans investigated the possible role of vitamin D in the prevention or treatment of immunological disorders. In this regard, low serum vitamin D levels have been reported in observational trials in human autoimmune disorders. The aim of the present paper was to review the potential implications of vitamin D in immune modulation, with special focus on thyroid autoimmune disorders.

中文翻译：

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维生素 D 的免疫调节作用及其在预防和治疗甲状腺自身免疫中的潜在作用：叙述性综述。

维生素 D 的主要作用是控制矿物质稳态。然而，最近的研究表明存在许多骨骼外效应。在后者中，临床前研究提供了关于维生素 D 参与先天性和适应性免疫以及自身免疫的一致数据。分子生物学研究表明，维生素 D 受体和维生素 D 酶复合物都在大量与矿物质稳态无关的细胞和组织中表达。相比之下，只有少数人体随机临床试验调查了维生素 D 在预防或治疗免疫疾病中的可能作用。在这方面，在人类自身免疫性疾病的观察性试验中报告了低血清维生素 D 水平。