Among the main functions of vitamin D, its ability to improve the integrity of the epithelium has mainly been observed as well as the ability to induce the synthesis of an antimicrobial peptide in epithelial cells and macrophages, thus directly improving host defense [103]. Vitamin D also promotes the differentiation of monocytes from macrophages [95], promotes the movement and phagocyability of macrophages [79], superoxide production and bacterial killing by innate immune cells. Hence, it promotes the processing of antigen presentation by dendritic cells [104].