Many dogs -- and their owners -- receive adequate amounts of vitamin D from regular sunshine exposure. Depending on his size, your dog requires approximately 500 international units of vitamin D per day. Since he is what he eats, if he's not receiving sufficient amounts from food or sunlight, you may need to supplement.
Whether or not the food you give your dog contains adequate amounts of vitamin D depends on its ingredients. While vitamin D is found in meat and eggs, it is not abundant in grains, vegetables, nuts or fruits. Since many commercial dog foods contain large amounts of grain products, that could affect the amount of vitamin D your dog eats each day. Check labels and feed your dog a primarily meat food to ensure adequate vitamin D intake.
Most high-quality dog foods contain sufficient levels of vitamin D for Fido. Other good sources of vitamin D include dairy products, such as yogurt or cottage cheese. Because some dairy products can cause gastrointestinal problems for dogs, feed small amounts until you are sure your dog can digest it. Cod liver oil and fish also contain vitamin D. If your vet does blood testing on your dog and concludes vitamin D is lacking, she can advise you on supplementation.
Vitamin D Levels
While vitamin D is necessary for good health, too much of it causes serious problems. If your dog consumes very large quantities of vitamin D, hypervitaminosis D might result. This causes the heart valves, kidney tubules and large vessel walls to undergo irreversible soft-tissue calcification, with death resulting either from chronic renal failure or a massive aortic rupture, according to "The Merck Veterinary Manual."
If a dog suffers from vitamin D deficiency, he could end up with rickets in puppyhood or osteomalacia as an adult canine. While rare, signs of rickets have been seen in puppies fed homemade foods with no supplementation, according to "The Merck Veterinary Manual." Rickets cause decrease of bone mineralization, and the puppy may limp or appear in pain. Osteomalacia, or soft bones, does not cause obvious signs in dogs.
Jane Meggitt has been a writer for more than 20 years. In addition to reporting for a major newspaper chain, she has been published in "Horse News," "Suburban Classic," "Hoof Beats," "Equine Journal" and other publications. She has a Bachelor of Arts in English from New York University and an Associate of Arts from the American Academy of Dramatics Arts, New York City.