Does My Cat Need Supplements?
by Dr. Alycia Washington, DVM, MS, | January 23, 2024

Dmytro Zinkevych / Shutterstock
If you’re on social media at all, you’re likely constantly getting targeted with the latest supplement gummies, powders, etc. While you might be all set in that department (and really need those ads to stop popping up!), the one curled up on your lap, purring away, could benefit from an extra vitamin boost.
Cat supplements can provide essential nutrients for your cat, including omega-3 fatty acids for skin and joint health, probiotics for digestive health, and glucosamine and chondroitin for joint support. First, remember that it’s important to consult with your veterinarian to determine if your cat needs supplements and which type is right for them. Some cats may not need any supplements, while others may benefit from certain types.
Many pet parents take supplements for their health and want the same benefits for their feline friends. Supplements are products that provide nutrients to the body in order to lower the risk or reduce the effects of certain diseases. Supplements for cats come in various forms, including tablets, capsules, powders, liquid, or gel.
Most healthy cats who are type: entry-hyperlink id: kinshipArticle-merge-1084 do not need additional supplements. Diets that are formulated for cats, complete, balanced, and certified by the Association of American Feed Control Officials (AAFCO) can provide cats with the nutrients they need. Some cats, especially those with nutrient deficiencies or underlying health issues, may benefit from nutritional supplements. Many cats who type: entry-hyperlink id: kinshipArticle-merge-1173require additional supplements to ensure they get adequate amounts of essential vitamins and minerals.

Not your mama’s multivitamin.
Cat supplements are designed to provide additional nutrients to prevent or address specific health concerns. Supplements should not be used in place of a proper diet but rather to support cats and help them live healthier lives. Pet parents may consider giving their type: entry-hyperlink id: kinshipArticle-merge-306 to:
Address nutrient deficiencies
Support joint health
Promote skin and coat health
Maintain digestive health
Provide immune support
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Address health conditions
Decrease anxiety
Pet parents want to ensure their cat’s wellbeing, and many ask their veterinarians about the best supplements for cats. The answer depends on the individual cat and the parent’s specific concerns. Commonly used cat supplements include:
Probiotics
Fish oil
Vitamins
Joint supplements
Immune support supplements
Stress and anxiety supplements
Digestive supplements

Tips for improving your cat’s appetite with these tasty add-ons.
Vitamin B is a water-soluble vitamin that serves as a catalyst for many of the body’s functions. Vitamin B deficiency in cats can lead to poor growth, low body weight, poor appetite, weakness, neurological signs, and anemia. Vitamin B12 (cobalamin) is particularly important in cats. Cats cannot produce vitamin B12 on their own and must source it from their diet.
Any underlying digestive condition that interferes with nutrient absorption, like diseases associated with the gastrointestinal tract, liver, or pancreas, can lead to low levels of vitamin B12. Signs of vitamin B12 deficiency in cats include vomiting, diarrhea, anorexia, poor body condition, and low blood cell counts. When faced with a cat displaying chronic gastrointestinal issues, many vets will recommend testing cobalamin levels. When vitamin B12 levels are low, supplementation (often via injections) is recommended.
Vitamin C (ascorbic acid) is a water-soluble vitamin that is important for immune function and its antioxidant properties. It’s also important for tissue growth and helps the body create hormones that regulate blood pressure. Cats are able to produce vitamin C in their liver, so vitamin C deficiency is rarely seen in healthy cats.
Vitamin C supplementation is rarely needed and can cause some kitties harm. Excess vitamin C is turned into oxalate before being excreted in the urine. This extra oxalate can put cats at risk of developing calcium oxalate crystals or stones in their bladders. On rare occasions, veterinarians will reach for vitamin C as part of a treatment plan for critically ill cats in an effort to help support the immune system and the body’s ability to maintain adequate blood pressure.
Vitamin D is a fat-soluble vitamin, meaning it can be absorbed and stored in the body along with fat. Unlike humans, cats are unable to produce vitamin D from sunlight, so they rely on dietary sources. Vitamin D plays an essential role in the absorption of calcium and phosphorus, and it is vital for healthy bone and muscle function.
Vitamin D deficiency can cause skeletal issues like rickets and osteomalacia — conditions in which cats develop weak, soft bones. Because vitamin D is closely linked to calcium, low levels can lead to muscle weakness, tremors, and seizures. Vitamin D deficiency is most often seen in cats with congenital abnormalities, chronic kidney disease, or being fed unbalanced diets. Because vitamin D is fat-soluble and can build up in the body to the point of toxicity, supplementation is not recommended unless under the guidance of a veterinarian.
Vitamin E (tocopherol) is a fat-soluble vitamin that serves as an important antioxidant. Some cat foods are formulated with vitamin E to prevent fatty acids from oxidizing and becoming rancid.
Vitamin E deficiency can lead to steatitis (inflammation of fat tissue) in cats. Symptoms of vitamin E deficiency/steatitis include lethargy, poor appetite, abdominal pain, abdominal fluid, and painful nodules under the skin. Feeding a diet that is complete and balanced is important to prevent vitamin E deficiency caused by insufficient dietary intake.
Your cat might just need a little boost to be back to their active self.
Even if your cat has no apparent health issues, talk to your vet before starting supplements. If your cat is not doing well, definitely seek veterinary advice before reaching for supplements. Your vet can use a medical history, physical exam findings, and diagnostic testing to determine if your cat has a specific condition that requires specific treatment and if supplements are appropriate. Symptoms that may cause cat parents to ask about supplements include:
Dull coat and skin
Chronic diarrhea/loose stools
Recurrent constipation
Mobility issues
Anxiety and stress
Viral diseases
Probiotics are the “type: entry-hyperlink id: kinshipArticle-merge-1652” that help keep the population of microbes balanced. They help maintain a healthy gastrointestinal tract and contribute to immune health. Probiotics are often given to cats that have chronic GI issues, such as vomiting, diarrhea, or recurrent constipation. They are also beneficial to cats with acute diarrhea or that were recently on antibiotics. Many probiotics for cats will contain Enterococcus, Bifidobacterium, Streptococcus, and/or Lactobacillus spp.
Types of probiotics for cats: Probiotics are formulated as powders, capsules, and pastes.
Risks of giving probiotics to cats: Some cats may experience flatulence or abdominal discomfort.
Fish oil is rich in omega-3 fatty acids and is commonly used to help cats with dry, flaky, itchy coats. type: entry-hyperlink id: kinshipArticle-merge-1405 also has anti-inflammatory properties and is sometimes recommended for cats with allergic skin disease, arthritis, chronic kidney disease, heart disease, inflammatory bowel disease, and cognitive dysfunction.
Types of fish oil supplements for cats: Fish oil typically comes in liquid or capsule form.
Risks of giving fish oil to cats: Some cats may experience gastrointestinal upset and weight gain. Less common side effects include pancreatitis, delayed wound healing and changes in blood clotting.
Most cat foods provide all the essential vitamins and minerals that a cat needs. Cats fed raw, homemade, or incomplete diets are more likely to need supplementation. It’s better to choose a complete and balanced diet. Cats requiring vitamins typically need a specific vitamin in a specific format, so it’s best to work with your vet to opt for a targeted approach, rather than giving a multivitamin that contains more than your cat needs.
Types of multivitamins for cats: Cat multivitamins often come in tablet, powder, or gel forms.
Risks of giving multivitamins to cats: It’s possible to overdose a cat or even cause toxicity with unnecessary vitamin supplementation.
Cats can develop arthritis due to abnormal joint development or age-related degeneration. type: entry-hyperlink id: kinshipArticle-merge-2092 can have chronic pain and mobility problems that impact daily activities. Joint supplements are often part of a well-rounded plan that can include weight control and exercise.
Types of joint supplements for cats: Chondroprotective drugs, such as glucosamine and chondroitin, are popular choices to protect joint cartilage. They are often formulated as chewable treats.
Risks of giving joint supplements to cats: Some cats experience GI upset.
L-Lysine is an amino acid used for immune support in cats dealing with chronic viral conditions, particularly feline herpesvirus. While there is no cure for the virus, supplementation can help decrease the frequency and severity of flare-ups.
Types of immune support supplements for cats: L-Lysine can be found in gel, paste, powder, or chewable forms.
Risks of giving immune support supplements to cats: Side effects are uncommon, but some cats may experience mild GI upset.
Stress can manifest in many ways in cats, including undesirable behaviors, urinary issues, and GI upset. Cat parents may reach for supplements to help their type: entry-hyperlink id: kinshipArticle-merge-788.
Types of stress and anxiety supplements for cats: Products for stress and anxiety range fromtype: entry-hyperlink id: kinshipArticle-merge-3758 (diffusers, collars) to amino acids like L-tryptophan and L-theanine (chewable treats).
Risks of giving stress and anxiety supplements to cats: Because behavior can be difficult to manage in cats, some products may not be effective.
Some cats — especially long-haired cats — benefit from hairball-control supplements. These products coat the fur that cats swallow during grooming and help the fur pass through the intestines easily.
Types of digestive supplements for cats: Hairball supplements are liquids or gels.
Risks of giving digestive supplements to cats: Some cats may experience diarrhea or flatulence.
Your cat might just need a little boost to be back to their active self.
Always consult with your veterinarian before starting any supplements, even if your cat seems healthy. Your vet can provide guidance on the most appropriate supplement for your goals and help you avoid unnecessary products or those that may lead to accidental overdose or toxicity.
Another important note is the lack of regulation in supplement products. Unlike drugs, supplements do not have to go through rigorous testing for safety and efficacy. Your vet can help you find reputable brands.
Some vitamins and supplements can easily be overdosed in cats and some are outright toxic. Those that are easily overdosed include:
Vitamin D
Vitamin C
Calcium
Multivitamins
Those to completely avoid include:
Human multivitamins
Iron supplements
Garlic supplements
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Green tea extract
Any product formulated with xylitol
Supplements containing essential oils
Cat supplements come in many forms including capsules, liquids, powders and pastes. Administration depends on the product and what your cat will tolerate.
Cat supplements can have unwanted side effects like gastrointestinal upset. Talk to your veterinarian if your cat is not doing well on a recommended supplement.
There are risks associated with giving a cat supplements, especially if they are not needed. Some vitamins and supplements can have detrimental effects or cause toxicity if given unnecessarily.

Alycia Washington is a small-animal emergency veterinarian with over 10 years of experience based in North Carolina. She works as a relief veterinarian and provides services to numerous emergency and specialty hospitals. She also works as a veterinary writer with a focus on educating pet parents.

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