In the ITP group, VitD and TGF-β1 (r = 0.421), Treg cells (r = 0.516), TGF-β1 and Treg cells (r = 0.563), and platelet count (r = 0.399, 0.305, 0.361, respectively, p  < 0.05). This evidence concerns the gene TGFB1 and autoimmune thrombocytopenic purpura.