It has been reported that dogs and cats with lymphoma (2,11), mast cell tumors (5), hemangiosarcoma, carcinoma, histiocytic sarcoma, and other cancers (10,11,12) all have 25vitD values below 40ng/mL. The relative risk of having cancer increases to almost 4x when 25vitD values are below 40ng/mL.
Chronic Enteropathy (IBD)
Disease severity and the incidence of chronic enteropathy (CE) in both cats and dogs increases substantially when 25vitD values fall below 40ng/mL (4,11). In CE, survivors vs non-survivors can be separated when 25vitD values fall below 30ng/mL (15,17,23,29).
Congestive heart disease is more prevalent in dogs with 25vitD values below 40ng/mL and there is a 2.6x increase in cardiovascular events (9). Heart remodeling in chronic valvular heart disease worsens as 25vitD values fall below 30 ng/mL (16).
Chronic Kidney Disease
Studies show acute and chronic kidney disease is more prevalent in dogs with 25vitD values below 40ng/mL (1,2). As 25vitD values fall below 40ng/mL, creatinine increases dramatically (19).
Hospitalized cats with 25vitD levels below 40ng/mL have an 8x higher incidence of dying (13) and hospitalized dogs with 25vitD levels below 33ng/mL have a 7x higher incidence of dying (28).
25vitD is the substrate for the enzymatic conversion to the active hormone calcitriol. When 25vitD values fall below 40ng/mL, there is difficulty in maintaining proper calcitriol levels (1).
As a result, ionized calcium can fall below the reference interval (4,26). Maintaining proper ionized calcium levels is vital for muscle and nerve function.
For references, please refer to the Growing Body of Evidence. VDI has concluded that the body of evidence supports a high risk of disease and/or death when 25VitD levels are below 40ng/mL (deficient).