Dietary Vitamin D Intake and Vitamin D Status in Canine Cancer Patients
In humans, low dietary vitamin D intake and a low vitamin D status have been linked to increased risk of cancer development. This association is starting to be explored in canines. This thesis is an investigation of the dietary vitamin D intake and vitamin D status of dogs with cancer, specifically osteosarcoma, lymphoma and mast cell tumours, in comparison to healthy dogs. Plasma 25(OH)D concentration was significantly higher in healthy dogs than in those with osteosarcoma and lymphoma, but not mast cell tumours. There was an independent effect of cancer, dietary vitamin D intake and plasma ionized calcium on plasma 25(OH)D concentrations. The independent effect of cancer suggests that dietary vitamin D intake is not responsible for observed differences in plasma 25(OH)D concentrations. Further research is needed to investigate whether decreased plasma 25(OH)D concentrations are a factor in cancer development, or a consequence of cancer.