Figure 3.

Vitamin D and adaptive immune system. The adaptive immune system is like Tai-Chi, namely, that it separates the Yin and the Yang. 1,25(OH)₂D₃ directly modulates T cell responses and polarization related to the inflammatory molecules Th1 and Th17 in order to give rise to protective Th2 and Treg cells. In addition, 1,25(OH)₂D₃ also inhibits the inflammatory Th1 and Th17 cytokines and upregulates the protective Th2 and Treg cytokines. When these effects are integrated, the adaptive immune system may produce lower levels of inflammation, atherosclerosis, and autoimmunity.