The importance of vitamin D in skeletal health is well known. This study reviewed vitamin D in nonskeletal disease.
Many nonskeletal tissues express the vitamin D receptor. Vitamin D deficiency has been linked with several human diseases and may play an important role in companion animal health. Dogs with chronic enteropathy and cats with inflammatory bowel disease and intestinal small-cell lymphoma have low vitamin D levels. The causal relationship is unclear.
Vitamin D metabolism in dogs and cats with renal disease has been studied because the active vitamin D metabolite 1,25(OH)2D is produced in the kidney. The role of vitamin D therapy in dogs and cats with renal disease is poorly defined. Lower median levels of 25(OH)D were associated with increased disease severity in dogs with chronic valvular heart disease. Studies have indicated that 1,25(OH)2D promotes cardiac contractility and inhibits hypertrophy.
Epidemiologic studies have suggested a link between vitamin D status and neoplasia in dogs. Vitamin D deficiency has long been associated with human mycobacterial infections; a recent study indicated this may also be the case in cats. Low vitamin D levels in humans have been associated with increased markers of inflammation.
Further studies are needed to clarify the role of vitamin D in inflammation in dogs. Low vitamin D levels have been linked with higher mortality risk in humans and cats. Cats and dogs offer a unique model by which to further evaluate vitamin D and nonskeletal disease.
