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Vitamins are biological compounds or micro-nutrients needed to perform many vital biological functions in the body and for growth and maintenance by all living organisms, and dogs are no exception.
The AKC (American Kennel Club) has included vitamin D in the list of seven essential vitamins for dogs. “Essential vitamin” means a dog’s body itself cannot produce these, so it must be supplied via diet or some other external source.
Just like it does in humans, vitamin D in dogs improves calcium absorption from the intestine, thus regulating calcium and phosphorus levels in the body.
A good calcium level in the body and proper proportion with phosphorus strengthens the bones, improves bone growth, aids in fracture healing, and plays a vital role in the appropriate functioning of muscles and nerves.
Experts also believe that vitamin D reduces the incidence of many health issues dogs commonly face, like arthritis, IBD (inflammatory bowel disease), dental issues, hyperthyroidism, and vision problems. Some researchers also show that vitamin D reduces the risk of heart problems, depression, and other neurological issues.
Can Dogs Get Vitamin D From Sunlight?
Contrary to humans (where vitamin D is also called “sunshine vitamin” because sunlight is a major source of vitamin D in humans), the amount of vitamin D derived from sunlight is not significant in dogs.
This is partially due to the lack of direct sunlight exposure on the skin due to the presence of fur that covers most of the body in dogs, but there is another reason that dogs do not get a significant amount of Vitamin D from sunlight, as well.
It is actually a chemical 7-DHC (a precursor to Vitamin D) that is converted to vitamin D by sun rays. Humans have a good level of 7-DHC in their skin, while dogs don’t have enough 7-DHC in their skin to meet the body’s requirements for the vitamin D.
So, even if a dog got enough direct sunlight exposure to their skin, they would not be able to process this chemical into vitamin D in the quantities that humans can.
Do Dogs Get Vitamin D From Licking?
Shockingly, dogs can actually supplement their vitamin C from licking.
This is because the 7-DHC chemical is present in the oil produced by skin cells; and vitamin D produced is absorbed by the skin back into the body.
However, in the case of dogs, the skin oil is absorbed by the fur, which doesn’t allow vitamin D absorption in the body.
So vitamin D stays on the fur and is consumed orally when they lick their fur to groom themselves.
How Do Dogs Get Vitamin D Naturally?
Dogs largely get Vitamin D orally, either from licking it off their fur or from their normal food intake.
Some everyday food items that are good sources of Vitamin D and your dog can eat are fish (like salmon, mackerel, tuna, herring, halibut, sardines, and bluefish), Cod liver oil, Egg yolks, Beef liver, Cheese, Yogurt, Mushrooms, Fortified oats, and Squash.
Every batch of homemade dog food I make has a certain amount of egg (with yolk) and organ meats to help ensure my dogs are getting enough Vitamin D.
Do Dogs Need Vitamin D Supplements?
You don’t need to give any vitamin supplements if your dog is on high quality, well-balanced commercial food such as the brands available from K9 Cuisine. This is because high-quality dog foods are fortified with all essential vitamins (including Vitamin D) to ensure the physical and mental wellbeing of the dog.
However, supplements can be given if your dog is not getting enough Vitamin D, or showing signs of deficiency.
If this is the case, hold off on administering any supplements intended for humans. Your best bet is going to be to contact your veterinarian; they will do a blood test to check the deficiency level and decide what dose of vitamin D supplement should be given.
Signs of Vitamin D Deficiency in Dogs
So how do you know if your dog has a Vitamin D deficiency?
As vitamin D is required to uptake calcium from the intestine, (and this is essential for proper growth and functioning bones, muscles, and nerves) Vitamin D deficiency can lead to osteomalacia and rickets, and can affect the proper functioning of muscles and nerves.
Common signs of vitamin D deficiency are brittle bones, decrease in muscle mass, fatigue, stunted growth, joint issues, etc. Dogs deficient in vitamin D are more likely to develop congestive heart failure, heart disease complications, soft bones, rickets, bone demineralization, and other bone disorders.
Daily Recommended Dose Of Vitamin D For Dogs
According to the Association of American Feed Control Officials the recommended range of daily doses of vitamin D for dogs is 500 international units (0.0125 mg) to 3,000 international units (0.075 mg) for every kilogram of live body weight. It is crucial to follow the recommended dose by the vet because an overdose can lead to vitamin D toxicity, which in extreme cases can be lethal.
Signs Of Vitamin D Toxicity In Dogs
A high intake of vitamin D means more absorption of calcium into the blood which will disturb the function of the nervous system, cardiovascular system, gastrointestinal tract, and kidneys.
Some common signs of vitamin D toxicity are anorexia, constipation, abdominal pain, excessive thirst, urination, drooling, vomiting, lethargy, muscle weakness, soft tissue demineralization, lameness, tremors, and convulsions.
