Effects of calcifediol supplementation on markers of chronic kidney disease‐mineral and bone disorder in dogs with chronic kidney disease

Background Chronic kidney disease‐mineral and bone disorder (CKD‐MBD) in dogs is associated with hypovitaminosis D, increased parathyroid hormone (PTH), and increased fibroblast growth factor‐23 (FGF‐23) concentrations. Best practice for vitamin D metabolite supplementation in CKD‐MBD remains unknown. Objective To provide an extended‐release calcifediol supplement to dogs with CKD and to measure its effects on variables indicative of CKD‐MBD. Animals Ten dogs with International Renal Interest Society stages 2 and 3 CKD. Methods In a prospective study, dogs received a calcifediol supplement for 84 days. Serum 25‐hydroxyvitamin D (25[OH]D), 1,25‐dihydroxyvitamin D (1,25[OH]2D), 24,25‐dihydroxyvitamin D (24,25[OH]2D), creatinine, calcium, phosphorus, PTH, plasma FGF‐23 concentrations, and urine profiles were measured monthly during supplementation. Urine calcium to creatinine (UCa/Cr) ratios and fractional excretion of calcium, phosphorus, and sodium were determined. Results All serum vitamin D metabolite concentrations increased significantly by day 84 (P