The Role of Vitamin D in Autoimmune Thyroid Diseases: From Immunomodulation to Clinical Implications

Vitamin D plays a role in immune regulation and is linked to autoimmune thyroid diseases like Hashimoto's thyroiditis and Graves' disease. Low levels of vitamin D are associated with a higher risk of these diseases, suggesting a preventive role. However, clinical studies on vitamin D supplementation show mixed results, with some reduction in thyroid autoantibody levels but no consistent impact on thyroid function or disease progression. Thus, vitamin D deficiency may be a modifiable risk marker rather than a therapeutic target, indicating the need for more research on its clinical implications.