TGFB1 and Hyperglycemia: Another study has shown that vitamin D can inhibit the activation of the RAAS and hyperglycemia-induced production of TGF-β (transforming growth factor-β), thus decreasing the number of TGF-β-stimulated renal interstitial fibroblasts and inhibiting renal tubular epithelial-mesenchymal transdifferentiation (36).