Hypovitaminosis D in dogs with inflammatory bowel disease and hypoalbuminaemia.

Objectives: To compare serum vitamin D metabolites and plasma parathyroid hormone concentrations in dogs with inflammatory bowel disease and normal albumin concentration, dogs with inflammatory bowel disease and hypoalbuminaemia, healthy dogs and hospitalised ill dogs with non-gastrointestinal illness.

Methods: Serum 25 hydroxyvitamin D and 1,25 dihydroxyvitamin D concentrations were measured in 36 healthy dogs, 49 hospitalised ill dogs with non-gastrointestinal illnesses, 21 dogs with inflammatory bowel disease and normoalbuminaemia and 12 dogs with inflammatory bowel disease and hypoalbuminaemia. Plasma parathyroid hormone and ionised calcium concentrations were measured in a subset of these dogs.

Results: Concentrations of serum 25 hydroxyvitamin D were lower in hypoalbuminaemic dogs with inflammatory bowel disease than in the healthy dogs (P<0·001), hospitalised ill dogs (P<0·001) and normoalbuminaemic dogs with inflammatory bowel disease (P<0·001). Dogs with inflammatory bowel disease and hypoalbuminaemia had a higher plasma concentration of parathyroid hormone (P<0·01) and lower plasma concentration of ionised calcium (P<0·001) than hospitalised ill dogs. Dogs with inflammatory bowel disease had a positive correlation between serum 25 hydroxyvitamin D concentrations and serum albumin (P<0·0001), serum calcium (P<0·0001) and plasma ionised calcium (P<0·0005) concentrations.

Clinical Significance: Dogs with inflammatory bowel disease and hypoalbuminaemia frequently have ionised hypocalcaemia, high parathyroid hormone and low serum 25 hydroxyvitamin D concentrations. Further studies are indicated to establish the pathogenesis of this disease complication as well as therapeutic strategies to reverse this state.