17 April 2023

Vitamin D in dogs – Dosage and how to give it

By Killian

Vitamin D in dogs - Dosage and how to give it

Vitamin D is an essential and fundamental vitamin for numerous functions in the body, highlighting the balance between calcium and phosphorus between the bones, kidney and parathyroid gland, bone mineralization, immune cell differentiation, insulin secretion, formation of blood cells, etc.

In order for dogs to obtain vitamin D, they must be fed a diet intended for the canine species, as this contains the necessary amounts of said vitamin that they require each day so that they do not present a deficit or toxicity that accumulates in organs such as the liver at the end of the day. cannot be eliminated in urine due to its lipid solubility and not water solubility. If you are interested in learning more about the vitamin D for dogs, its dose and how to give itcontinue reading this AnimalWised article.

What is vitamin D?

Vitamin D is a key nutrient for regulate the balance and assimilation of phosphorus and calcium, being a vitamin soluble in fat but not in water, so if a dog ingests more vitamin D than necessary, it accumulates in the body (liver and fatty tissue), and cannot be eliminated through urine. This excess of vitamin D can be dangerous for the dog as it can lead to kidney failure or death.

In humans and others, the synthesis of vitamin D begins with exposure to the sun through the skin, transforming 7-dehydrocholesterol into provitamin D3, but the dog cannot synthesize it in sufficient quantity, possibly due to increased activity. of 7-dehydrocholesterol-Δ7-reductase.

For this, for a dog to get sufficient amount of vitamin D must be provided through animal feed (cholecalciferol or vitamin D3) or vegetables (ergocalciferol or vitamin D2), although there are also nutritional supplements.

What is vitamin D used for in dogs?

What does vitamin D do in dogs? Vitamin D in dogs has multiple functions, highlighting homeostasis or balance between calcium and phosphorus through the axis established between the bones, the parathyroid gland and the kidney, favoring its reabsorption avoiding losses.

Vitamin D is also involved in bone remodeling and mineralization, forming the bones and being key to the development of the skeleton. It also has an action on the cells of the small intestine, favoring the absorption of calcium and phosphorus that will pass to the bones.

This vitamin is also involved in the differentiation of cells of the immune system promoting the conversion of monocytes to macrophages, hematopoiesis, insulin secretion, reduction of proteinuria and inflammation.

For all this, if your dog you don’t get enough of vitamin D and you wonder “how to know if my dog ​​lacks vitamin D” you should know that bones tend to demineralize, curve, and weaken being able to develop irreversible malformations, rickets in puppies and osteomalacia in adults.

Vitamin D Dosage in Dogs

Dogs require a minimum daily dose of 227 IU per kilogram of dry food for the canine species, doses of more than 2,700 IU/kg of body weight being toxicbeing well above the safety limit in dogs.

Although in much lesser amounts than in other species, dogs can also convert vitamin D in the most superficial layers of the skin, although the consumption of dry feed or human foods rich in vitamin D will cover their needs, avoiding deficiencies.

Once absorbed, vitamin D arrives through the lymphatic system and the portal system to the liver, requiring the activation of chylomicrons, digestive enzymes, bile acids, transcalciferins, and vitamin D binding proteins.

Vitamin D in dogs - Dosage and how to give it - Dosage of vitamin D in dogs

How to give vitamin D to my dog?

A dog with the correct diet based on the consumption of a dry feed for the canine species should not have vitamin D deficiency problems.

However, if a dog does not have a correct diet or is based on the consumption of too many vegetables, possibly due to the vegetarian or vegan habits of its caregivers, it is likely that it will develop a deficiency of this vitamin since for plants to obtain vitamin D it is necessary that they be dried in the sun, requiring yes or yes vitamin supplements to obtain the necessary dose.

Foods for human consumption such as egg yolk, butter, kidneys, fatty fish and cod liver oil they are also a source of vitamin D for dogs.

Vitamin D in dogs - Dosage and how to give it - How to give vitamin D to my dog?

Side Effects of Vitamin D in Dogs

When handlers give dogs vitamin D supplements or, worse, a human supplement with much higher doses than a dog requires, it can cause overvitaminosis or vitamin D toxicity in dogs, manifesting with clinical signs such as:

This is because vitamin D accumulates in liver and adipose tissue of the dog by not being able to eliminate excess vitamin D through urine.

Contraindications of vitamin D in dogs

The main contraindication to the use of vitamin D in dogs is to offer them supplementation to dogs whose diet is already complete enough for being fed with a complete food for the canine species that contains adequate levels of this vitamin.

This is because excess vitamin D is toxic to the dog and accumulates in its organic tissues, causing the serious symptoms described above.

If you want to read more articles similar to Vitamin D in dogs – Dosage and how to give itwe recommend that you enter our section on balanced diets.


Aveaca. Nutritional requirements in dogs and cats. Available in:


A. Elices. (2010). Atlas of nutrition and practical feeding in dogs and cats. Servetus.