Immunomodulatory Mechanisms and Therapeutic Potential of Vitamin D in Immune Thrombocytopenia.

In addition to its classical function in regulating phosphorus and calcium equilibrium, the immunoregulatory effects of vitamin D (VD) have increasingly drawn attention in recent investigations. A deficiency of VD has been associated with multiple autoimmune pathologies. Immune thrombocytopenia (ITP), a hemorrhagic disorder mediated by autoantibodies, manifests through accelerated platelet destruction accompanied by impaired platelet production. Accumulating evidence suggests that VD is intricately involved in ITP pathophysiology, with serum VD concentrations strongly associated with clinical symptoms, disease severity, and overall prognosis. However, the mechanisms underlying these associations remain incompletely understood, and the limited number of studies conducted thus far highlights the necessity for further investigation. This study reviews the correlation between VD and ITP, the immunological mechanisms through which VD regulates ITP, and the potential therapeutic value of VD supplementation in ITP management. Future multicenter clinical trials and mechanistic studies are warranted to develop novel therapeutic strategies for ITP.