Beyond its classical effects on calcium and phosphate homeostasis and bone formation [1], vitamin D has also non-classical functions [29] in the regulation of hormone synthesis and secretion, including the parathyroid hormone (PHT), the fibroblast growth-factor 23 (FGF-23) or insulin in the cell proliferation in the skin, in cancer and in the immune system. Here, FGF23 is linked to cancer.