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Dogs and Vitamin D

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With the arrival of spring, lots of us will be spending extra time soaking up the sunshine outside with our dogs. With all of that time spent staying at home this past year, many of us could also use that extra Vitamin D boost! 

Vitamin D is known as the “sunshine vitamin,” because it is naturally produced by our bodies with exposure to sunlight. While Vitamin D is essential for dogs and humans alike, dogs don’t produce it the same way we do. Soaking up the sun is an enjoyable bonding activity, but ultimately your pooch needs to get his fix through his diet.

Why is Vitamin D Important? 

Vitamin D is crucial for maintaining the health of humans and canines alike. Vitamin D’s most prominent role is to regulate calcium and phosphorus absorption, which is necessary for growing and maintaining healthy bones. 

If your dog’s diet is deficient in Vitamin D, he may experience poor muscle activity, heart disease, and weakened bones or bone disorders, and other conditions. 

Before mixing some precautionary Vitamin D supplements into Fido’s food bowl, make sure he’s eating a healthy, well-rounded diet. The most common sources of Vitamin D for dogs are liver, fish, egg yolks, beef, and dairy; most commercial pet foods also contain Vitamin D. If your pup is eating a healthy diet, chances are he’s also getting a healthy dose of Vitamin D. 

If you’re worried that your furry friend may be deficient in Vitamin D, consult your vet. When it comes to this vitamin in particular, it’s incredibly easy to have too much of a good thing—in fact, too much Vitamin D can be incredibly toxic to dogs. 


Too Much of a Good Thing

When it comes to Vitamin D and dogs, you want to take the cautious route and assume that less is more. While Vitamin D deficiencies can cause unwanted health issues, too much of the vitamin can be poisonous, and even fatal. 

Vitamin D is a fat-soluble vitamin. This means that, unlike water-soluble vitamins, excess Vitamin D gets stored in the liver and fat tissue instead of being excreted with the urine. Too much calcium staying in the body can then cause tissues in the body to calcify, or harden. 

It doesn’t take much to cause Vitamin D toxicity. Just 0.45 mg per 10 pounds of body weight can be poisonous, and 9 mg in a 10-pound dog can be fatal. 

There are three main ways that dogs could end up ingesting dangerous amounts of Vitamin D: 

Eating food with too much Vitamin D
In 2018, several dog food products were recalled due to dangerously high levels of Vitamin D. Fortunately, credible companies diligently test their food for proper dosage amounts. 

Eating your Vitamin D supplements 
Because Vitamin D deficiency is such a common ailment among humans, many of us own Vitamin D supplements. Be sure to store these somewhere where your curious dog can’t sniff them out and perform a taste test, as this can easily lead to toxicity.

Ingesting rat poison 
Many rodenticides, or rat poisons, contain cholecalciferol (Vitamin D3). Unfortunately, rat poison isn’t only poisonous to rats—the high calcium levels will quickly lead to toxicity, including renal failure and cardiac issues. 


Symptoms of Vitamin D Poisoning

Symptoms of Vitamin D poisoning can appear anywhere from 12-36 hours after ingestion; they usually start out subtly, and gradually increase in severity. 

Common symptoms of Vitamin D poisoning include:

  • Loss of appetite
  • Increased thirst 
  • Drooling
  • Diarrhea
  • Dark, tarry stools
  • Vomiting
  • Breathing difficulties
  • Increased urination
  • Weight loss 
  • Joint/muscle issues 

If you notice any concerning changes in your dog’s behavior, consult your vet immediately. If you know what your dog ingested, such as your Vitamin D supplements or a specific brand of dog food, bring the packaging with you to show the vet for reference. 

Depending on the severity of the toxicity, your vet may decide to induce vomiting and/or administer charcoal to absorb excess Vitamin D. Treatment can also include an overnight stay with an IV to support the kidneys; in some cases, the dog may also be given an oral steroid to prevent further calcium absorption. 


What About Sunshine? 

For humans, the main source of Vitamin D is sunshine and supplements. While we should keep those supplements away from our four-legged friends, plenty of sunshine is still perfectly safe and healthy for your dog. 

Sunshine doesn’t necessarily affect your dog’s Vitamin D levels—as mentioned before, his diet should be the main source of the vitamin. You don’t need to worry about a Vitamin D overdose if you spend too much time outside with your dog; after all, regular exercise and exploration is encouraged. 

That being said, be aware that like humans, dogs can also get sunburnt or suffer from heatstroke. Offer plenty of shade and rest and avoid going out during the hottest time of day. Of course, when seasonal allergies are an issue, you’ll also want to avoid the peak pollen hours. 

For dogs experiencing seasonal allergies, PetHonesty Allergy Support Chews can improve environmental, food, and skin allergies by supporting a healthy immune system. 


Sources: 
https://vethelpdirect.com/vetblog/2020/06/29/do-dogs-need-vitamin-d-supplements/
https://www.animalbiome.com/blog/your-dog-needs-vitamin-d-too-much-can-be-toxic
https://www.fda.gov/animal-veterinary/animal-health-literacy/vitamin-d-toxicity-dogs
https://www.thesprucepets.com/vitamin-d-poisoning-in-dogs-4771518