background: vitamin d plays a critical role in the regulation of growth and differentiation of squamous epithelium. the pleiotropic effects of 1,25-dihydroxyvitamin d3 [1,25(oh)2d3], include proliferative, pro-apoptotic, and pro-differentiation effects on numerous cell types. although 1,25-dihydroxyvitamin d3 is involved in the regulation and differentiation of epithelium, there is no data in t...