University of Cagliari, A.O.U. of Cagliari, Italy.
Clin Exp Rheumatol. 2011 Nov-Dec;29(6):1024-31. Epub 2011 Dec 22.
Vitamin D is essential not only for calcium and bone metabolism, but it also may exert other biological activities, including immunomodulation through the expression of vitamin D receptor in antigen-presenting cells and activated T cells. Evidence from animal models and human prospective studies of rheumatoid arthritis, multiple sclerosis, type I diabetes, and systemic lupus erythematosus, indeed suggested an important role for vitamin D as a modifiable environmental factor in autoimmune diseases. In systemic sclerosis (SSc), this role has not been completely dissected, although recent studies clearly evidenced a high prevalence of vitamin D deficiency. Moreover, some degree of association between vitamin D deficiency and disease activity or phenotype characteristics has also been observed. Vitamin D deficiency in SSc may be related to several factors: insufficient sun exposure due to disability and skin fibrosis, insufficient intake because of gut involvement and malabsorption. Although it is advisable to regularly check vitamin D status in these patients, there is no consensus about which vitamin D supplementation regimen might be sufficient to modulate immunological homeostasis, and possibly reduce disease activity or severity, thus further prospective studies are needed. Moreover, novel vitamin D analogues with more pronounced immune modulatory effect and lower activity on calcium metabolism are in the pipeline, and might represent a great innovative opportunity for the treatment of vitamin D deficiency in such autoimmune disorders.
维生素 D 不仅对钙和骨骼代谢至关重要，它还可能发挥其他生物学活性，包括通过抗原呈递细胞和活化 T 细胞中维生素 D 受体的表达来调节免疫。来自类风湿关节炎、多发性硬化症、I 型糖尿病和系统性红斑狼疮的动物模型和人类前瞻性研究的证据确实表明，维生素 D 作为一种可改变的环境因素在自身免疫性疾病中具有重要作用。在系统性硬化症 (SSc) 中，这一作用尚未被完全阐明，尽管最近的研究清楚地表明维生素 D 缺乏症的高患病率。此外，还观察到维生素 D 缺乏症与疾病活动或表型特征之间存在一定程度的关联。SSc 中的维生素 D 缺乏可能与多种因素有关：由于残疾和皮肤纤维化导致的日晒不足、肠道受累和吸收不良导致的摄入不足。尽管建议定期检查这些患者的维生素 D 状态，但对于哪种维生素 D 补充方案足以调节免疫稳态并可能降低疾病活动或严重程度，尚无共识，因此需要进一步的前瞻性研究。此外，具有更强免疫调节作用和更低钙代谢活性的新型维生素 D 类似物正在研发中，这可能为治疗此类自身免疫性疾病中的维生素 D 缺乏提供一个巨大的创新机会。
