Studies have found correlations between insufficient levels of vitamin D and increased risk of developing non-skeletal pathologies such as cardiovascular diseases (including hypertension), cancer, and chronic inflammatory diseases such as rheumatoid arthritis and asthma.  Vitamin D receptors are expressed in many tissues throughout the body, through which vitamin D is believed to directly or indirectly regulate more than 2000 genes.  Emerging research has shown that many tissues will locally convert 25(OH)D to the active form 1,25(OH)2D without influence from serum calcium.  This also may explain why various storage forms of vitamin D do not necessarily correlate with circulating concentrations of active vitamin D.  However, serum concentrations of 25(OH)D have been evaluated in both humans and dogs and have correlated with risk of various disease states.  The optimal vitamin D concentration for immunologic and other cell microenvironment factors may be different than that required to prevent rickets.  In dogs, low 25(OH)D and 1,25(OH)2D have been correlated with canine lymphoma, cutaneous mast cell tumors, hyperparathyroidism, renal disease, inflammatory bowel disease, and heart disease.  In human - and more recently veterinary – medicine, vitamin D “sufficiency” has been defined by examining the inverse relationship between intact parathyroid hormone (iPTH) and vitamin D.  The latter is considered sufficient when both iPTH concentration and biological variation plateau with increasing 25(OH)D.  In dogs this has been determined to be 100-125 mg/dL.  Future investigations should focus on routine therapeutic monitoring of vitamin D concentrations in patients with chronic disease, and the potential benefit of supplementing to the point of sufficiency.

Progress and future investigations in understanding the role of vitamin D in canine and feline health and disease

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.