A new study published in Veterinary and Comparative Oncology examined the vitamin D status of dogs to determine a range of sufficiency. The study also showed that low vitamin D levels were associated with an increased risk of cancer.
Since research has shown that the effects of vitamin D extend beyond bone health, vitamin D sufficiency has been extensively evaluated in humans. However, little research has been conducted in dogs.
Researchers recently created the first study to examine the range of vitamin D sufficiency in dogs. The researchers were also interested in how low vitamin D levels related to the risk of cancer.
In the study, the researchers defined sufficiency as the point at which vitamin D status was met by a near maximum suppression of the parathyroid hormone (PTH).
Normally, when vitamin D levels are low the body produces PTH to pull calcium from the bones to meet the body’s needs, since a lack of vitamin D reduces the body’s ability to absorb calcium from the diet.
When vitamin D levels are sufficient for bone health, the production of the PTH is maximally suppressed indicating that vitamin D is effectively absorbing calcium from the diet to meet the body’s needs.
The researchers analyzed at what vitamin D range the PTH was maximally suppressed in 282 dogs and found it to be in the range of 100-120 ng/ml.
The researchers then analyzed the relationship between the dogs’ vitamin D levels and the prevalence of cancer and found that dogs with a vitamin D level below 40 ng/ml were 3.9 times more likely to have cancer.
This correlates with research in humans indicating an increased risk for many cancers in individuals with vitamin D levels below 40 ng/ml.
“Serum vitamin D measurement can identify dogs for which supplementation may improve health and response to cancer therapy,” the researchers concluded.