Shopping Cart
0

Vitamin D for Dogs: Do Dogs Need Vitamin D?

Dr. Abdul Basit

As a pet parent, I was terrified when my typically energetic husky, Rocky, suddenly became unusually fatigued. After a vet visit, I learned he had a vitamin D deficiency.

Left untreated, Rocky would’ve struggled with chronic pain, lethargy, and a weakened immune system. Immediately after the visit, I sought to fully understand vitamin D for dogs—and all of its caveats—and how to properly supplement to keep my buddy happy. 

Here’s what I found.

What Is Vitamin D and How Do Dogs Process It?

Source: Depositphotos

This is where the confusion arises: dogs and humans use vitamin D in practically the same way, but the difference lies in the way we process it.

  1. When humans are exposed to sunlight, specifically UV-B rays, a substance (7-dehydrocholesterol) in our skin is converted to vitamin D, a fat-soluble vitamin. 
  2. The latter travels to our liver, where it’s converted into calcidiol, the form that circulates in our bloodstream and that we use to measure our vitamin D levels. 
  3. Then, it moves to the kidneys, where it’s converted into calcitriol, the active form that benefits us.

The problem is that dogs can’t produce vitamin D effectively from the sun—they can’t just soak in it like you and I do and call it a day because their fur gets in the way. 

They actually take most of their Vitamin D from their diet. And no, shaving your dog is a bad idea; they’ll be at an increased risk of sunburns and skin issues.

What Are the Benefits of Vitamin D for Dogs?

The sunshine vitamin benefits our furry friends in similar ways as it benefits us. It lets them absorb and retain calcium and phosphorus from the food they eat, the former being critical for bone and muscle health. 

Here’s a breakdown of the most important benefits:

  • It ensures proper bone and teeth development, health, and maintenance.
  • It enhances their ability to fight infections and inflammation by modulating the immune system.
  • It regulates cell growth, differentiation, and programmed death to inhibit the development of some cancers.
  • It maintains proper muscle function, including the heart, and reduces the risk of muscle weakness.
  • It aids in the regulation of various hormones in their body, which in turn influences their metabolism and mood.
  • It aids in the functioning of nerves for proper coordination and responses to stimuli.
  • It contributes towards keeping their coat healthy and shiny!

How Do I Know My Dog Is Deficient In Vitamin D?

Many symptoms of vitamin D deficiency can be mistaken for other health issues, as it influences a range of bodily functions. Even worse, you might think some of the milder signs, such as fatigue, are just due to your dog having a bad day. 

The definitive way to diagnose such a deficiency in your pet is to take it to the vet and get a blood test done. 

Below are some signs you need to pay attention to.

Common Symptoms

Source: Depositphotos

One of the first symptoms I noticed in Rocky was his change in behavior and fatigue. 

He seemed unusually tired, irritated, and less interested in our day-to-day activities and mealtimes. He gave up playing and his hearty appetite for around-the-clock naps. If you’ve ever owned a vocal furball as a husky before, you know how inconceivable that is!

Assuming the worst, I took him to the vet. I later learned that clinical signs of vitamin D deficiency in dogs also include:

  • Noticeable muscle tremors and twitching, which gradually become more noticeable, particularly when your pet is moving around.
  • Signs of discomfort when touched due to bone pain, which extends to a reluctance to jump around, climb stairs, or engage in rough play, as well as stiff gait or lameness to their walk.
  • Dental issues, which contribute to a loss of appetite. For puppies, it can manifest as delayed tooth development.
  • Greater susceptibility to falling ill; your dog’s immune system becomes compromised and recovery takes much longer than usual.
  • Drier, flakier skin, and a less shiny coat.

Some pet owners found that dogs with vitamin D deficiency also suffer from weight loss. However, this is a consequence of their reduced appetite and isn’t immediately noticeable.

Long-Term Consequences

Long-term vitamin deficiencies are debilitating to both dogs and humans. 

Since vitamin D is responsible for phosphorus and calcium absorption and retention, many of the issues that will emerge down the line will be bone- and muscle-related.

  • Osteomalacia: This condition is similar to osteoporosis in humans, where the dog’s bones become soft and deformed, leading to fractures and permanent skeletal issues.
  • Rickets: This condition affects puppies and leads to soft and deformed bones. It manifests as bone pain, swelling, a stiff gait, difficulty rising, bowed limbs, and fractures.
  • Muscle Atrophy: Over time, your dog will struggle with engaging in play or day-to-day activities due to muscle weakness and loss. In severe cases, it can lead to heart issues.
  • Weakened Immune System: Your dog might become more susceptible to infections due to their compromised immune system.
  • Increased Cancer Risk: Vitamin D contributes to cell regulation. When it’s deficient, the chance for some types of cancer to emerge in dogs increases.
  • Cognitive Decline: Vitamin D deficiency impacts cognitive function, and older dogs may exhibit signs of confusion, disorientation, depression, anxiety, and more.

A poor vitamin D level has a cascading effect on a dog’s health. It will stunt their growth, shorten their lifespan, and lead to chronic pain. Worse, when the deficiency is so severe that it atrophies their bones, the damage may become irreversible!

Sources of Vitamin D for Dogs

Source: Deposiphotos

Your dog will derive its vitamin D requirements from its diet. 

Here are some foods you can provide to keep them healthy, with the amount of vitamin D in each measured in International Units (IU).

According to the Association for American Feed Control Officials (AAFCO), a kilogram of adult dog food should contain no less than 500 IUs (growth and reproduction minimum/adult maintenance minimum), but should not exceed 3,000 IUs (adult maintenance maximum).

Natural Sources

FoodServing SizeVitamin D Amount
Egg Yolks1 Yolk~18–56 IU
Beef Liver3.5 oz/100 g~50 IU
Cod Liver Oil1 tsp./4.9 ml~450 IU
Salmon3.5 oz/100 g~360–685 IU
Mackerel3.5 oz/100 g~360 IU
Halibut3.5 oz/100 g~600 IU
Fresh Atlantic Herring3.5 oz/100 g~1,600 IU

Other foods your dog can enjoy that are rich in vitamin D include fortified yogurt, kefir, oatmeal, squash, and some types of cheese.

Commercial Dog Foods

Source: Depositphotos

Most commercial pet food manufacturers fortify their products by adding vitamin D3 (cholecalciferol). Alternatively, they incorporate natural sources rich in it, such as fish oils or egg products.

When reading the labels, look for vitamin D or D3 in the guaranteed analysis section, or stick to products that have an AAFCO statement on the packaging. 

Labels such as “Complete & Balanced” guarantee that the dog food is sufficient in every way for your furry friend.

Remember that your dog’s nutritional needs will vary depending on their age; puppies require less vitamin D than adult dogs. 

Most commercial products are age-graded and will meet the requirements without leaving room for concern. However, if you feed your dog homemade food, make sure you monitor the vitamin D levels carefully!

Vitamin D Poisoning: Is It Real?

Yes, after a certain threshold, consuming more of a vitamin poses risks to both humans and dogs. Too much vitamin D doesn’t mean better, and as a well-meaning parent, you might inadvertently commit this error.

Usually, vitamin D toxicity in dogs is usually the result of the accidental ingestion of supplements. It’s difficult for your dog to overdose on this vitamin through natural sources because it would take quite a large amount of food.

However, if you suspect your dog is at risk, note:

  • Neurological symptoms, such as weakness, depression, confusion, seizures, or lethargy.
  • Gastrointestinal issues, such as vomiting, diarrhea, or a loss of appetite.
  • Increased thirst and urination.
  • Impaired kidney function, including increased blood urea nitrogen (BUN) and creatinine levels.
  • Muscle tremors or stiffness.
  • Bone pain or lameness.
  • Calcification of soft tissues.

Once toxicity occurs, it can be difficult to treat, as high levels of vitamin D interfere with the absorption and utilization of other nutrients, impede many bodily functions, and damage your dog’s organs. However, if you notice the symptoms early and take him to the vet, they can be mitigated!

Vitamin D Supplements and Your Dog’s Intake: What You Need to Know

If your homemade meals are lacking in vitamin D or you don’t have access to high-quality commercial dog food, consider vitamin D supplementation, particularly if you have a puppy, a pregnant/nursing dog, or a senior dog.

Supplements are necessary for dogs with medical conditions that interfere with the absorption or utilization of this vitamin. Inflammatory bowel disease (IBD), chronic pancreatitis, and chronic kidney disease are common culprits.

It’s a good idea to consult with your veterinarian first; they’ll prescribe specialized supplements if your dog requires higher doses.

However, if you do the math yourself (and are confident that your dog can benefit from more vitamin D), consider oral supplements. You can easily add them to your dog’s food and they are packed with essential vitamins to keep your pet healthy and happy!

Conclusion

Much like us, healthy dogs are the result of a balanced diet with sufficient amounts of vitamin D. If it’s deficient, debilitating musculoskeletal conditions and a range of other health issues can emerge. Unfortunately, dogs can’t derive sufficient amounts of it from sunlight exposure; they rely on their diet for this essential nutrient.

High-quality food and supplements can ensure your dog remains happy and vibrant, but make sure you conduct regular checkups and consult with your veterinarian before you make a significant change to your pet’s diet or notice concerning symptoms.

Dr. Abdul Basit
Latest posts by Dr. Abdul Basit (see all)
{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}