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Vitamin C for Dogs: Benefits and Uses

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Vitamin C is among the many vitamins and minerals that are important for dogs. It is an antioxidant that can fight harmful free radicals, reduce inflammation, and prevent cognitive decline associated with aging.

Dogs, unlike humans, are able to make vitamin C in their bodies and don’t rely on food or supplements for their daily dose.

Even though dogs can make their own vitamin C, there are some reasons dogs may benefit from additional supplementation. 

What Is Vitamin C?

Vitamin C, or ascorbic acid, is a water-soluble vitamin that plays a role in immune health, collagen synthesis (which is important for normal bone formation), wound healing, and endocrine function. Studies suggest that vitamin C has important intracellular functions to help reduce inflammation or oxidative stress that can lead to chronic health issues like allergies and cancer

Dogs are able to synthesize vitamin C from glucose in the liver. It is then widely distributed through body tissues. 

Food can be used for natural sources of vitamin C, especially for chronic health conditions and higher levels of stress. Foods with higher levels of vitamin C for dogs that are safe to give include broccoli, kale, bell peppers, papaya, brussel sprouts, and kiwifruit. These whole foods provide natural vitamin C for dogs, which provide antioxidant support and reduce inflammation while supporting the immune system. 

Herbs like chickweed and comfrey are also great natural sources of of this vitamin that help with allergies and pain. 

Benefits of Vitamin C for Dogs


The studies in dogs are lacking for showcasing the effectiveness of vitamin C, but many integrative and holistic veterinarians are seeing results using IV vitamin C therapy in cancer treatments, possibly due to its antioxidant properties. 

Vitamin C is also commonly used for urinary tract infections in dogs. Whole food sources of vitamin C, such as cranberries, support the bladder lining and prevent bacteria better than supplemental vitamin C [1].  Excess vitamin C is excreted in the urine as oxalate, and a high concentration of oxalate has the potential to contribute to the formation of calcium oxalate bladder stones. 

Care is important if supplementing with synthetic vitamin C versus using whole food options, since it can potentially lead to side effects. 

How to Give Vitamin C to Dogs

Vitamin C is not commonly added to a dog’s food or wellness regimen due to a dog’s ability to synthesize it naturally. Ascorbic acid may be seen on a pet food label for its antioxidant properties to help preserve kibble diets.  

When using synthetic vitamin C, it comes in chews, pills, capsules, and powders. There is not a general dosing guideline because supplementation is often non-essential.  

There are also different forms of vitamin C to choose from, some which may be more easily absorbed than others. Your veterinarian can discuss side effects and how to choose the best option if they believe it is the right option for your dog.

Before adding any kind of vitamin C to your dog’s regimen, it is best to discuss dosing with your veterinarian to avoid a vitamin C overdose.

Side Effects for Dogs

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Because dogs make vitamin C on their own, there can be risks of giving too much – especially when using supplements.  

Overall vitamin C is fairly safe, because it is a water soluble vitamin. If excess vitamin C is ingested, the dog will urinate it out of the body. But too much may lead to the formation of oxalate bladder stones. Pet parents should avoid any kind of vitamin C supplement if their dog is prone to bladder stones or has a low urinary pH. 

Also, for dogs who have sensitive GI tracts, adding additional vitamin C to their diets is not recommended unless partnering with a holistic or integrative veterinarian due to the risk of diarrhea or vomiting. 

Do Dogs Need Vitamin C Supplements?

Most healthy dogs do not need vitamin C supplements and extra supplementation could lead to an overdose if you’re not careful. 

However, if your veterinarian recommends a vitamin C supplement to your dog, make sure to choose a reputable brand that adheres to safety and quality standards. 

When purchasing supplements, there are numerous pet-specific products. It is important to look for the National Animal Supplement Council (NASC) label on the brand, since this shows the company had to successfully pass certain requirements and standards for their products. 

These products can be bought through veterinary clinics, online, or in pet stores. Higher quality supplements should list the concentration of each ingredient on the label.  This is important to make sure you are not giving too much of one ingredient over time that could lead to GI upset or other health concerns.  

Higher quality products should be free of fillers. Many supplement companies add unnecessary ingredients, like binders and flavorings, which can flare allergies or GI upset. Avoid ingredients like animal digest and artificial flavors, colorings and sweeteners.