What Is Vitamin D3 for Dogs?

Vitamin D3 for Dogs

Vitamin D3 for dogs is an essential nutrient. It is one of four fat-soluble vitamins, with the others being vitamin A, vitamin E, and vitamin K. 

Vitamin D plays an important role in the absorption of calcium and phosphorus. By regulating the calcium and phosphorus levels in the body, it helps maintain strong bones. Also, vitamin D is important for immune system function, a healthy nervous system, and muscle movement.

Vitamin D3 (cholecalciferol), a specific form of vitamin D, is produced by the human body in sunlight and found in animal foods and dietary supplements. Vitamin D3 is popularly known as the “sunshine vitamin“ because people synthesize it via sunlight exposure (as a response to ultraviolet light). However, dogs make very little of their own vitamin D3 from the sun and need adequate levels of vitamin D in their food.

The other main form of vitamin D is vitamin D2 (ergocalciferol), which is made by plants, yeasts, and fungi and included in some dietary supplements. 

Vitamin D deficiency occurs if the dog does not get enough vitamin D3 from its pet food or if the absorption and utilization of the vitamin are impaired.

Rx Vitamins Rx D3 Liquid Vitamin D for Dogs & Cats
  • RxD3 is a nutritional supplement for dogs and cats that contains pure Vitamin D3 in the form of cholecalciferol.
  • It helps maintain and replace normal levels of Vitamin D3 that may be lacking from your pet’s diets.
  • Vitamin D3 helps with calcium and phosphorus absorption in the body and helps support immune system health and function.

Is Vitamin D3 Safe for Dogs?

Yes, vitamin D3 for dogs is safe when used correctly. Any vitamin D3 supplement given should be prescribed by a vet and in the right doses or concentrations. Typically, these products would be recommended by your veterinarian if your dog was diagnosed with a deficiency of vitamin D.

High levels of either form of vitamin D may result in vitamin D toxicity. However, vitamin D2 has a wider safety margin compared to vitamin D3.

Excess amounts of vitamin D can cause acute kidney failure and death. This is because vitamin D is not excreted via the urine like water-soluble vitamins would be excreted. As a fat-soluble vitamin, it instead accumulates within the body.

Since both high and low vitamin D levels are dangerous for dogs, it is important to stick to the doses recommended by the veterinarian. Also, it is inadvisable to use human vitamin D supplements, as they contain higher concentrations.

What are the Benefits of Vitamin D3 for Dogs?

Vitamin D3 for dogs helps with mineral metabolism, is important for a healthy immune system, and prevents certain health conditions. Here is a closer look at the benefits of vitamin D3:

  • Strong Teeth & Bones: Vitamin D3 helps absorb calcium and phosphorus from the food the dog eats. It also facilitates the balance of phosphorus and calcium homeostasis, which means that when calcium levels are low, vitamin D3 helps restore them to safe levels. This prevents osteomalacia (bone softening) in adult animals, rickets in puppies, and bone deformities. Adequate vitamin D3 levels may also improve the range of motion in dogs with arthritis.
  • Healthy Heart: Low levels of vitamin D3 may be a risk factor for congestive heart failure in dogs. Sufficient vitamin D3 prevents a dog from having risks and complications due to heart disease.
  • Strong Immune System: Vitamin D3 helps with immune system modulation as it regulates the production of inflammatory cytokines and immune cells.
  • Chronic Disease Prevention: Appropriate levels of vitamin D3 also prevent kidney disease, inflammatory bowel disease, and hyperparathyroidism (excess production of parathyroid hormones).

What are Good Sources of Vitamin D3 for Dogs?

Vitamin D3 for Dogs

There are several supplements that make excellent sources of vitamin D3 for dogs. While it is highly advisable to talk to your vet first, we will provide a short review of some of the best-selling vitamin D supplements.

  • Rx Vitamins Rx D3 Liquid Vitamin D for Dogs & Cats: This high-quality supplement contains pure cholecalciferol. It is an immune-supporting supplement that contains MCT oil. Plus, it is very easy to use – just add the drops required to your dog’s food.

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  • Nutrition Strength Vitamin D Complex for Dogs: This supplement is a great source of vitamin D, calcium, magnesium, and zinc. It improves a dog’s immune system, maintains strong bones and teeth, promotes muscle growth, and maintains a healthy cardiac function.

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  • PetHonesty 10-in-1 Dog Multivitamin with Glucosamine: This great supplement containing vitamin D3 for dogs will provide comprehensive health benefits. It also has glucosamine, which helps improve joint health. The krill oil in the formula supports healthy skin and a shiny coat.

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  • ProSense Vitamin Solutions: This vitamin supplement is suitable for dogs of all breeds and ages and helps provide overall health. It is formulated with a blend of vitamins, minerals, and antioxidants to provide well-balanced nutrients for your dogs.

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  • BravoPaws Dental Chew Dog Treat Avodent Sticks: The sticks are tasty and health-boosting for dogs. They contain adequate concentrations of vitamin D3, vitamin C, curcuminoids, and zinc. Plus, for dog owners who are concerned about additives, this product is free from grains, fillers, and artificial additives.

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What Food Has Vitamin D3 for Dogs?

Animal-sourced foods are the best sources of vitamin D. An appropriately fed dog without underlying health conditions can get all the vitamin D they need from its normal diet.  Here is a more detailed review of some of the best natural sources of vitamin D3 for dogs.

  • Fatty Fish: Fatty fish are the greatest source of vitamin D for dogs. This includes salmon, swordfish, tuna, cod, and sardines. The high-fat levels in fish facilitate the absorption and utilization of vitamin D3.
  • Fish Liver Oils: Cod liver oil and salmon oil are great sources of vitamin D3 for dogs. In addition to vitamins, they are rich in antioxidants and omega-3 fatty acids.
  • Beef Liver: Beef liver is also rich in vitamin D3. Beef liver is also an excellent source of vitamin A and offers proteins and several essential minerals.
  • Egg Yolks: While not as vitamin D-rich as the rest of the foods on this list, egg yolks still have healthy concentrations of vitamin D3, along with other vitamins, minerals, and healthy fats.

Finally, when it comes to commercial dog food, the Association of American Feed Control Officials (AAFCO) gives strict recommendations regarding the levels of vitamin D. Namely, one kilogram of adult dog food must contain a minimum of 500 IU (0.0125 mg) of vitamin D and a maximum of 3,000 IU (0.075 mg).

How Often Should You Give a Dog Vitamin D3?

Vitamin D3 for Dogs

The frequency of supplementing a vitamin D-deficient dog will depend on the case. While some dogs need daily, others need weekly supplements. Disease-free dogs with a healthy diet typically do not require extra supplementation of vitamin D.

When determining how often to give a dog vitamin D3, you need to consult with a veterinarian. Using the dog’s history, physical exam, and blood test, the vet will establish the vitamin D deficiency and consider the dog’s diet and overall health to give the best advice.

How Much Vitamin D3 Should I Give My Dog?

If you are supplementing vitamin D3, follow your veterinarian’s dosage recommendations. If feeding a fresh, whole-food diet, it should contain a minimum of 125 IU of vitamin D content per 1000 calories and a maximum of 750 IU for an active 33-pound dog. That is equivalent to an ounce of wild salmon every other day if the dog’s diet otherwise contained no vitamin D.

A vitamin D3 supplement should contain a maximum of 100-120ng/ml for daily intake. Commercial dog food should have enough vitamin D, a minimum of 500 IU, and not more than 3000 IU per kg of dog food. Follow either the recommendations on the packaging or your veterinarian’s recommendation to ensure your pet is getting enough vitamin D.

Dr. Rhiannon Koehler says, “Most dogs will receive an adequate amount of vitamin D in their diet and don’t require extra supplementation. Because there is the risk of vitamin D toxicity, you should always follow your veterinarian’s recommendations regarding dosing or whether your pet actually needs this supplement.”

How Much Vitamin D3 Is Toxic for Dogs?

An amount of 0.45 mg per 10 pounds of body weight can be poisonous to dogs. The fatal dose of vitamin D for dogs is around 9 mg per 10 pounds of body weight.

The two most common scenarios in which vitamin D toxicity occurs are rodenticide poisoning and ingestion of excessive vitamin D supplements.

What Are Signs of Too Much Vitamin D in Dogs?

Vitamin D poisoning causes hypercalcemia (high blood levels of calcium) due to increased calcium absorption. The signs of vitamin D poisoning and subsequent hypercalcemia include gastrointestinal upset (diarrhea, vomiting, appetite loss), increased thirst, frequent urination, abdominal pain, weight loss, and depression.

High levels of vitamin D can cause renal failure. This can be fatal, too. Therefore, pet owners need to seek veterinary help if they notice unusual signs and symptoms.

The treatment for vitamin D poisoning will include detoxification (vomiting induction and activated charcoal), intravenous fluids, oral steroids (to reduce calcium absorption), furosemide (to eliminate the excess calcium), and more. In severe cases, the dog will be hospitalized until stable.