Rapid improvement in vitamin D status with dietary 25-hydroxycholecalciferol in vitamin D insufficient dogs.

Vitamin D insufficiency is associated with various disease processes. We determined whether consumption of a diet supplemented with HyD, a 25-hydroxycholecalciferol (25(OH)D) source, would safely increase plasma 25(OH)D concentrations in Golden Retrievers with low vitamin D status. We hypothesised that dietary supplementation with HyD would rapidly increase and sustain plasma 25(OH)D levels in healthy Golden Retrievers with low vitamin D status compared with supplementation with vitamin D.