Association between vitamin D metabolites, vitamin D binding protein, and proteinuria in dogs

Abstract

Background: Proteinuria has been associated with progression of renal disease and increased morbidity and mortality in dogs and people. In people, proteinuria also has been associated with hypovitaminosis D. Little is known about the relationship between vitamin D metabolism and proteinuria in dogs. Objectives: To further elucidate vitamin D status in dogs with protein-losing nephropathy (PLN) and minimal to no azotemia. We hypothesized that vitamin D metabolites would be lower in dogs with PLN compared to healthy dogs. Animals: Twenty-three client-owned adult dogs with PLN and 10 healthy control dogs. Methods: Serum 25-hydroxyvitamin D (25[OH]D), 1,25-dihydroxyvitamin D (1,25[OH]2D), 24,25-dihydroxyvitamin D (24,25[OH]2D), serum vitamin D binding protein (VDBP), and urine 25(OH)D concentrations were measured. Results: Compared to healthy dogs, dogs with PLN had lower concentrations of all vitamin D metabolites (P