Lew Olson's newly revised edition is filled with an abundance of new topics and information. Whether you are new to home feeding or a seasoned raw feeder, have a senior dog or a new puppy, a pregnant mom or a toy breed, this book presents all the information you need to make the best nutritional decisions for your dog.

The Importance of Vitamin D

Most of the articles I write focus on fresh food diets and the importance of adding certain supplements to your dog’s meals for their overall good health. Raw and home cooked meals provide most of the nutrients your dog needs for good health, but it is important to understand that some of the nutrients our dogs need are not plentiful enough in the foods we feed, so supplementing is important. An important vitamin that does not always get enough attention is vitamin D3, so I am going to talk about the importance of this vitamin and why it is necessary for good health.

There are water-soluble and fat-soluble vitamins. Water-soluble vitamins such as vitamin B and C are easily flushed from the body. Fat-soluble vitamins such as Vitamin A and E however, are stored in the dog’s body. Vitamin D3 (Cholecalciferol) is also a fat-soluble vitamin and like vitamin A and E, any excess is stored in the liver and bloodstream.

Many people associate vitamin D with sunshine. While people can easily absorb vitamin D3 from the sun, this is not true for our canine friends. Because of the dog’s thick coat and the oil on their skin, their ability to absorb vitamin D from the sun is poor. Dogs need to get their source of vitamin D3 primarily through their diet.

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The most common benefit of vitamin D is its role in helping with the uptake of calcium in the body, which prevents diseases like rickets where bones become fibrous. Vitamin D3 also helps prevent osteoporosis, muscle weakness, diabetes, heart conditions and high blood pressure. Additionally, it helps with skin conditions such as vitiligo, which is loss of pigment. More recently, vitamin D3 has been found to help with autoimmune conditions, Inflammatory Bowel Disease and cancer, as it helps certain chemotherapies work more efficiently.





Studies have also shown dogs with congestive heart failure are usually low in vitamin D3 blood serum.


Too much vitamin D3 or a possible overdose of the vitamin has always been a concern. During my research on D3, many articles warned of this problem. However, the most common cause of overdose was when dogs consumed rat poison. Most rat poisons contain extremely high doses of vitamin D3, which causes ‘bleeding out’ and death of rodents. It would be very difficult to give a dog that high of a dose of vitamin D. Even offering a much lower toxic dose, it would have to be taken daily for many months to achieve the dangerous effects. On rare occasions, this has happened with commercial pet foods where mistakes were made in the amounts on vitamin D3 put in the pet food.


While there are issues and concerns with vitamin D toxicity, the larger concern is vitamin D deficiency and this is an extreme concern for puppies. They need vitamin D3 to help with growing healthy bones, tooth development, immunity, heart health, nerve development and muscle tone. However, with the new information available, it is just as important for adult dogs to get enough vitamin D for heart health, immunity, protection against autoimmune disease and IBD, and cancer prevention.

How much vitamin D3 should be given to dogs? Vitamin D3 is not always easy to find in foods and dogs have little ability to absorb vitamin D3 from the sun. In the wild, dogs have a greater ability to find vitamin D3 in food because they eat the organ meat and blood of their prey, both of which contain D3. We avoid feeding too much liver because it is a rich food. Excess amounts can cause diarrhea and stomach upset. The meat we purchase for our dogs has been drained of most of the blood. Therefore, vitamin D3 is not as plentiful in the foods we feed our dogs.

The recommended dose of vitamin D3 for your dog is 227 IU per pound of food served. A toxic dose is given at over 2722 IU per pound of food; however, that amount would have to be given over several months to reach a dangerous toxicity level.

Vitamin D3 Recommended Dosage

Total IUs Daily Daily Food Consumption Dog’s Weight
400 IU 1-1/2 to 2 pounds > 75 pounds (large)
300 IU 1 to 1-1/2 pounds 30 – 75 pounds (medium)
100 – 200 IU 8 oz. to 12 oz. < 30 pounds (small)

These doses of vitamin D3 are safe. Remember, dosage is based on the amount of food you feed your dog, NOT your dog’s weight! In certain situations such as heart disease, cancer, autoimmune illness or IBD, I might double the recommended dose.

Foods with good levels of vitamin D include:

  • Canned Salmon
  • Canned Mackerel
  • Canned Sardines
  • Fortified dairy products such as yogurt and goats milk
  • Beef liver
  • Egg yolks

It is important to try to feed at least one of these types of food in your dog’s diet daily, along with adequate supplementation. Good supplements that contain the right amount of vitamin D3 are Berte’s Daily Blend and Berte’s Immune Blend. Both products contain 400 IU of vitamin D3 per tablespoon (large dog size) and come in a powder form that is palatable and very easy to add to raw or home-cooked diets.

Giving the amounts of vitamin D3 as indicated in the article and taking care to add vitamin D rich foods to your dog’s diet will help keep bones and teeth healthy and may help prevent heart disease, autoimmune issues, digestion problems and cancer. And Remember, vitamin D3 is most important for growing puppies!