Vitamin D deficiency is one of the most common vitamin deficiencies across different populations. It has primarily been implicated in the development of metabolic bone disease in adults and children. However, in recent years its role in immunomodulation has also emerged and has gained further importance since the occurrence of coronavirus disease 2019 (COVID-19). Here, we describe the most recent literature on vitamin D and its impact on immunomodulatory pathways. Furthermore, the current evidence on the impact of vitamin D deficiency on COVID-19 infection, severity, and prognosis is summarised. We also highlight the key research gaps in this field that need further research.

维生素 D 缺乏症是不同人群中最常见的维生素缺乏症之一。它主要与成人和儿童代谢性骨病的发展有关。然而，近年来，自 2019 年冠状病毒病 (COVID-19) 发生以来，其在免疫调节中的作用也开始显现，并变得更加重要。在这里，我们描述了有关维生素 D 及其对免疫调节途径影响的最新文献。此外，还总结了维生素 D 缺乏对 COVID-19 感染、严重程度和预后影响的现有证据。我们还强调了该领域需要进一步研究的关键研究空白。