How Vitamin D Deficiency may Affect Your Dog’s Health

Man’s best friend

For centuries, dogs have been coined man’s best friend. The support and companionship these special animals offer is unlike that of any other species. In fact, research shows that dogs experience a wide range of emotions, including love, joy, fear and even grief over a loss of a loved one.

Furthermore, there are a variety of health benefits associated with owning a dog, including but not limited to stress reduction, improved relaxation, increased physical activity, and even an increased life span. 

How Vitamin D Deficiency may Affect Your Dog’s Health

Is your dog’s health at risk? 

As pet owners, we do our best to ensure our trusted companions receive the love and care they need to thrive. But what happens when your dog becomes ill, despite your best efforts? Unfortunately, this reality is all too common for pet owners.

Dogs are prone to many of the same acute and chronic illnesses as people. However, since our pets can’t tell us when they feel unwell, disease states often go unnoticed, leading to the development of critical illness.

Like people, poor dietary habits, excess weight and a lack of physical activity can significantly impair affect treatment outcomes in ill dogs. In addition, research suggests vitamin D may play a role in various canine diseases. However, until recently, researchers have yet to evaluate how vitamin D deficiency may affect critical illness outcome in dogs.

New research on vitamin D and canine health

In a study published earlier this year, researchers hypothesized that, like humans, critically ill dogs are more likely to be vitamin D deficient, and that vitamin D deficiency may affect disease severity and survival. A total of 99 dogs were included in the study, 82 of which were admitted to the University of Missouri Veterinary Health Center Intensive Care Unit (ICU) between October of 2016 and January of 2017 for critical illness. The remaining 17 healthy dogs served as controls.

The researchers evaluated the dog’s physical health, lab values (including vitamin D levels) and disease severity within 24 hours of admission. They recorded overall length of hospital stay, reason for ICU admission and survival outcomes. In addition, the researchers followed up with each dog owner to determine survival a day after discharge and again 30 days after discharge from ICU.

The researchers found that healthy dogs had significantly higher vitamin D levels than those who were critically ill or had sepsis. Dogs with higher vitamin D levels experienced lower illness severity. Vitamin D status was an independent predictor of survival. In addition, every 1 ng/ml increase in vitamin D status was associated with a 6% decreased risk of mortality. 

The researchers concluded,

“Hospitalized dogs with critical illness have decreased serum 25(OH)D concentrations compared to healthy dogs and can be used to predict survival in this cohort.”

Final thoughts

These findings suggest vitamin D may plays a key role in illness severity and treatment outcomes among critically ill dogs. Unfortunately, research on this topic is still in its infancy. Furthermore, there is a lack of research evaluating the ideal dose of vitamin D for dogs, so it is difficult to determine what the ideal 25(OH)D reference range for dogs is at this time.

Until research suggests otherwise, the Vitamin D Council hypothesizes vitamin D metabolism among dogs is similar to humans, and thus dogs need about 100 IU/kg body weight. Do you have any questions or experiences about vitamin D and canine health you would like to share? If so, please reach out to the Vitamin D Council at