TNF and Parkinson disease: In addition, 1,25(OH)2D3 induces the release of neurotrophin and synthesis of Ca2+-binding proteins such as parvalbumin, inhibits the synthesis of inducible iNOS, macrophage colony-stimulating factor, TNF-α, down-regulates L-type voltage sensitive Ca2+ channel (LVSCC), and upregulates γ-glutamyl transpeptidase activity, which are also reported to be the potential neuroprotective mechanisms of VD in PD (Figure 2A) (91–93).