Dogs can produce some essential vitamins in their own bodies, while others must be obtained through food. In short: Dogs can (partly) produce vitamin D, vitamin K, and vitamin C themselves. Vitamin A, vitamin E, and B vitamins must be included in their diet. Note: Even the self-produced vitamins often need some dietary supplementation.

Don't give too much

Dogs can produce vitamin D in their skin through exposure to sunlight, although this process is less efficient than in humans, partly due to their thick coat. Therefore, dogs get most of their vitamin D through food. Supplementing vitamin D is usually unnecessary and can even be harmful!

Dogs can produce vitamin K in their intestines through bacterial fermentation. In addition, they receive it through complete dog food. Generally, it is not necessary to supplement vitamin K for healthy dogs. However, if your dog is unwell, supplementation might be needed. For example, long-term antibiotic use can lower vitamin K production. Certain metabolic issues or intestinal diseases can also make vitamin K supplementation necessary.

Like many other mammals, dogs can synthesize vitamin C in their liver. Therefore, it’s usually not necessary to give dogs a vitamin C supplement. Vitamin C is also found in fruits and vegetables, so you can offer your dog a fresh treat now and then, especially during times of stress or illness.

Always in the diet

The vitamins that must always be present in your dog's diet are: Vitamin A, vitamin E, and the B vitamins.

Vitamin A is important for healthy skin, coat, and eyes. Since dogs cannot produce this vitamin themselves, it must always be included in their diet. Puppies and lactating females often need slightly more vitamin A. Complete dog food always contains added vitamin A, but if you prepare your dog’s food yourself, make sure it includes enough of this essential vitamin.

Vitamin E helps protect cells from damage and is also important for muscles and fertility. This vitamin must be obtained through food and is usually found in complete pet food. Vitamin E naturally occurs in small amounts in animal products and more abundantly in vegetable oils, nuts, and leafy green vegetables.

The vitamin B complex includes several vitamins such as B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folic acid), and B12 (cobalamin). These must be obtained through food and are essential for various body functions, including metabolism and the nervous system. Vitamin B12 is especially important.