There were data on vitamin D treatment in 5215 patients, 24.8% received 25(OH) vitamin D (20.6% on CKD G3b vs. 30.2% on CKD G4) and 13.6% received 1,25(OH)2 vitamin D (10.2% on CKD G3b vs. 18.0% on CKD G4) significantly more on CKD G4 and on the PTH-data Group (Chi2p < .05) (Table 2). This evidence concerns the gene PTH and chronic kidney disease.