INS and chronic kidney disease: A randomized controlled-study including non-diabetic individuals with CKD found that insulin resistance incidence was significantly higher in the vitamin D-deficient than in the vitamin D-normal group; in the same study, the supplementation with activated vitamin D analogs significantly ameliorated insulin sensitivity and β-cell function, supporting the hypothesis of a direct role of vitamin D in regulating metabolic homeostasis in CKD [119].