Abstract
Autoimmune disorders, characterized by an overactive immune system attacking healthy tissues, are a significant global health concern. A common thread among these disorders is vitamin D deficiency. While the exact relationship between vitamin D and autoimmunity remains a hot research arena, plenty of reports have suggested a strong association between vitamin D and autoimmune conditions, including systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, and Type 1 diabetes, among others. Type 1 diabetes, in particular, has been extensively studied in relation to vitamin D. Evidence suggests that vitamin D deficiency may play a role in the development of this autoimmune disease. Beyond its well-known function in bone health, vitamin D acts as a key regulator of both innate and adaptive immune responses. This review sought to explore the complex interplay between vitamin D and the immune system, with a particular focus on its potential role in autoimmunity, especially Type 1 diabetes. Moreover, the coupled therapy and clinical trials that have investigated the use of vitamin D as a therapeutic intervention for autoimmune disorders were also examined, highlighting both successes and limitations.