Yes, dogs need vitamins, but most healthy dogs get them all from their food. A food labeled complete and balanced must supply every essential vitamin and mineral within set limits, say Tufts veterinary nutritionists. A supplement makes sense for a home-cooked diet built on a nutritionist's recipe, according to the Merck Veterinary Manual, or when your vet finds a specific need. Extras can harm, because some nutrients have narrow safety ranges.
Key points
- Tufts's list of essential nutrients for dogs has 11 vitamins and 12 minerals. Dogs make their own vitamin C, and gut bacteria usually supply vitamin K.
- On the bag or can, look for an AAFCO statement that says complete and balanced for your dog's life stage. "Intermittent or supplemental feeding only" means the product is not a whole diet.
- Keep treats, toppers, and table food to 10% of your dog's daily calories or less.
- Do not add calcium to a growing large-breed puppy's food: a diet above 3% calcium (dry matter) causes more severe bone and joint problems than one with 1% to 3%.
- If your dog eats a bottle of vitamins or a rat or mouse poison, call your vet or a pet poison hotline at once.
Do dogs need vitamins? What complete food already covers
Every dog needs vitamins and minerals, and a complete and balanced food is made to supply all of them. Tufts veterinary nutritionists say a dog that eats a commercial food should not need any vitamin or mineral supplement unless a specific health issue has been identified.
A quick definition: vitamins and minerals are nutrients, and a supplement is any product you add on top of the food, such as a multivitamin, fish oil or a probiotic.
Most dogs are covered because of how a complete food is made. A food whose AAFCO nutritional adequacy statement says complete and balanced must include all the essential nutrients, each between the minimum requirement and any maximum, per Tufts's list of essential nutrients. In higher-income countries, nutritional diseases are rarely seen in dogs fed a good-quality commercial complete and balanced diet, notes the Merck Veterinary Manual.
The exceptions come down to diet and health. Nutrition problems occur most often in dogs fed unbalanced homemade diets, Merck adds. A specific health issue that your vet identifies can also call for a supplement. The decision table further down shows what to do in each case.
Should you give your dog a multivitamin?
Not if your dog is healthy and eats a complete and balanced food, per the Tufts advice above. If you think something is missing, ask your vet first and bring the food label to the visit.
What vitamins and minerals do dogs need?
Dogs need 11 vitamins and 12 minerals, 23 in all, on Tufts veterinary nutritionists' list of essential nutrients, plus a few fatty acids. Find each nutrient’s type, main role, and safety notes in the table below, where provided by the Merck Veterinary Manual.
| Nutrient | Type | What to know | Source |
|---|---|---|---|
| Vitamin A | Fat-soluble vitamin | Needed for normal vision, growth, reproduction, immune function, and healthy skin and lining tissues. Poisoning is rare in dogs | Tufts; Merck |
| Vitamin D | Fat-soluble vitamin | Increases absorption of calcium and phosphorus and helps deposit both in bone. Too much raises blood calcium and phosphorus and can calcify soft tissues for good | Tufts; Merck |
| Vitamin E | Fat-soluble vitamin | Works as an antioxidant. Very high doses can interfere with absorption of the other fat-soluble vitamins | Tufts; Merck |
| Thiamine (B1) | Water-soluble vitamin | Most B vitamins act as enzyme helpers (cofactors) | Tufts; Merck |
| Riboflavin (B2) | Water-soluble vitamin | Most B vitamins act as enzyme helpers (cofactors) | Tufts; Merck |
| Niacin (B3) | Water-soluble vitamin | Most B vitamins act as enzyme helpers (cofactors) | Tufts; Merck |
| Pantothenic acid (B5) | Water-soluble vitamin | Most B vitamins act as enzyme helpers (cofactors) | Tufts; Merck |
| Pyridoxine (B6) | Water-soluble vitamin | Most B vitamins act as enzyme helpers (cofactors) | Tufts; Merck |
| Folic acid or folate (B9) | Water-soluble vitamin | Most B vitamins act as enzyme helpers (cofactors) | Tufts; Merck |
| Vitamin B12 | Water-soluble vitamin | Most B vitamins act as enzyme helpers (cofactors) | Tufts; Merck |
| Choline | Vitamin | A complete and balanced food must supply it | Tufts |
| Vitamin C | Water-soluble vitamin | No AAFCO requirement: dogs make their own from glucose in the liver | Merck |
| Vitamin K | Fat-soluble vitamin | Essential, but gut bacteria typically provide enough; the Tufts list marks it for cats | Tufts; Merck |
| Calcium | Mineral | Deposited in bone with phosphorus, with help from vitamin D. In young, fast-growing large-breed dogs, more than 3% of the diet (dry matter) causes more severe bone and joint problems than 1% to 3% | Tufts; Merck |
| Phosphorus | Mineral | Deposited in bone with calcium, with help from vitamin D | Tufts; Merck |
| Potassium | Mineral | A complete and balanced food must supply it | Tufts |
| Sodium | Mineral | A complete and balanced food must supply it | Tufts |
| Chloride | Mineral | A complete and balanced food must supply it | Tufts |
| Magnesium | Mineral | A complete and balanced food must supply it | Tufts |
| Iron | Mineral | A complete and balanced food must supply it | Tufts |
| Copper | Mineral | A complete and balanced food must supply it | Tufts |
| Manganese | Mineral | A complete and balanced food must supply it | Tufts |
| Zinc | Mineral | A complete and balanced food must supply it | Tufts |
| Iodine | Mineral | A complete and balanced food must supply it | Tufts |
| Selenium | Mineral | A complete and balanced food must supply it | Tufts |
Tufts's list also names fatty acids for dogs: linoleic acid, plus alpha-linolenic acid and EPA and DHA for growth.
Fat-soluble or water-soluble: why the type matters
The type tells you how much risk an excess carries. Vitamins A, D, E, and K are fat-soluble, and the B vitamins and vitamin C are water-soluble, Merck explains. Water-soluble vitamins carry much less risk of toxicity, because the body does not readily store an excess.
Do dogs need vitamin C and vitamin K?
Dogs need both, but their bodies usually cover them. Dogs make their own vitamin C from glucose in the liver, so AAFCO sets no vitamin C requirement for dogs and cats, according to Merck. Vitamin K is essential too, but a dog's gut bacteria typically provide enough.
Before you share your own vitamin C tablets, read whether human vitamin C is safe for dogs.
What vitamins are good for dogs?
Every vitamin in the table is good for your dog in the amounts a complete and balanced food supplies. More is not better. Tufts warns that some nutrients have narrow safety ranges, as the risks section below explains.
How to tell if your dog's food is complete and balanced
Read the AAFCO nutritional adequacy statement on the bag or can, and look for "complete and balanced" plus your dog's life stage. A product labeled for "intermittent or supplemental feeding only" is not meant to be the whole diet, according to the Merck Veterinary Manual.
The 30-second label check
Work through the statement in this order.
- Find the AAFCO statement. It is a short sentence on the label that names AAFCO.
- Check the claim and how it was supported. One kind of statement says the food is "formulated to meet the nutritional levels established by the AAFCO Dog Food Nutrient Profiles". The other says "animal feeding tests using AAFCO procedures substantiate" that it "provides complete and balanced nutrition".
- Read the life stage. The statement names growth, maintenance, gestation/lactation, or all life stages. Make sure it matches your dog.
- Spot "intermittent or supplemental feeding only". A product with this line is not meant to be the whole diet, so check toppers and mixers for it too.
- Count the extras. Treats and other extras should supply no more than 10% of your dog's daily calories, so they do not unbalance the diet, says Tufts Petfoodology's treat guidance. Table scraps add up fast.
When does a dog need a supplement?
Usually when eating a home-cooked diet or when your vet identifies a specific health need. Healthy dogs eating complete and balanced commercial food generally don’t need vitamin or mineral supplements, according to Tufts veterinary nutritionists.
Find your dog’s situation in the table, then read the notes below.
| Your dog | Does the food cover it? | What to do | Who decides |
|---|---|---|---|
| Healthy adult on a complete and balanced food | Yes | No vitamin or mineral supplement unless your vet finds a specific health issue (Tufts) | Your vet |
| Home-cooked diet | Not on its own: studies show most recipes that owners design, or find in magazines, books or online, lack one or more essential nutrients (Tufts) | Use a recipe from a board-certified veterinary nutritionist and the exact supplements it names (Merck) | A board-certified veterinary nutritionist |
| Growing puppy of a large breed | Yes, if the label names growth or all life stages | Do not add calcium: too much harms bone development (Merck) | Your vet |
| Senior dog | Yes, if the food is complete and balanced | Same rule as other adults; ask about supplements at the senior checkup (Tufts) | Your vet |
| Dull, dry or flaky coat | Your vet checks first: a health problem may be the cause | See your vet before adding a fatty acid supplement (Merck) | Your vet |
| Diagnosed condition | Your vet decides | Your vet chooses any supplement and the dose, for example fish oil for some heart, kidney or joint problems (Tufts) | Your vet |
| Many treats or table scraps | Not if extras pass 10% of daily calories | Cut extras back to 10% of calories instead of adding a vitamin (Tufts) | You |
What supplements should I give my dog?
Only the ones that your vet, or a veterinary nutritionist for a home-cooked diet, names for a clear reason. For a healthy adult on a complete and balanced food, that usually means no vitamin or mineral supplement at all.
Home-cooked diets need a nutritionist's recipe
Home-cooked diets usually need supplements, with each one specified in the recipe. Merck recommends recipes from a board-certified veterinary nutritionist, rather than the internet or a book. Tufts says good recipes specify exact ingredients and amounts, including sources of calcium, B vitamins, iron, zinc, and essential fatty acids. Balancing the diet may require a veterinary supplement or several human supplements, sometimes 7 to 9 products.
Meals based on just a few foods often lack nutrients. Merck warns that mostly meat or hamburger-and-rice diets can cause calcium deficiency and secondary nutritional hyperparathyroidism, a hormonal disorder that weakens bones.
Large-breed puppies need no extra calcium
Don’t add calcium to a large-breed puppy’s complete and balanced food. Merck reports that diets containing over 3% calcium by dry weight cause more severe bone and joint development problems (osteochondrosis) than diets containing 1% to 3%. This applies to young, fast-growing large-breed dogs. Unnecessary mineral supplements can also upset the diet’s mineral balance.
A dull or flaky coat needs a vet check first
Ask your vet first about coat problems. Merck notes that fatty acid supplements are often recommended for dry, flaky skin and dull coats. But your vet should check for an underlying health issue before you add them.
Why more is not better: risks of extra vitamins and minerals
Extra vitamins and minerals can harm your dog, since some nutrients have narrow safety ranges, warn Tufts veterinary nutritionists. Give supplements containing these nutrients only when your vet specifically recommends them.
Supplements can also interact with one another, medications, and your dog’s regular diet, according to Tufts's advice on sensible supplement use. Tell your vet about every product your dog gets, including chews and toppers.
Can dogs overdose on vitamins?
Yes. Vitamin D poisoning has followed excess vitamin D added by mistake to commercial pet foods, and dogs eating rat and mouse poisons that contain vitamin D3, reports the Merck Veterinary Manual. It raises blood calcium and phosphorus and can calcify soft tissues for good.
Vitamin A poisoning is rare in dogs. Very high doses of vitamin E, however, can interfere with absorption of the other fat-soluble vitamins.
Minerals need the same care. Merck advises against giving them without a reason, because it can cause a mineral imbalance. For growing large-breed puppies, the calcium limit in the nutrient table above applies.
Can I give my dog human vitamins?
Not unless your vet says so. A supplement proven safe for people may not be safe for pets, warns a Tufts Petfoodology article on pet supplements.
Keep all supplements out of reach, including yours and your dog’s. Joint supplements are generally safe, but dogs can overdose. Store them as carefully as medications, advises Cornell's Riney Canine Health Center.
If your dog eats a bottle of vitamins or supplements, or a rat or mouse poison, call your veterinarian or a pet poison hotline at once. Have the package with you when you call.
Which supplement ingredients have the most research behind them?
Omega-3 fatty acids from fish oil come first. Among joint supplements, they currently have the most support in the literature, says Cornell's Riney Canine Health Center.
Fish oil and omega-3 fatty acids
At the right dose, omega-3 fatty acids may ease joint discomfort, according to Tufts Petfoodology's fish oil article. They can help dogs and cats with heart disease and may benefit some pets with kidney disease. Fish oil may not suit pets with digestive or bleeding disorders. Ask your vet about the dose and a brand with reliable quality control.
Glucosamine and chondroitin
A 2017 Tufts Petfoodology article suggested that good-quality glucosamine/chondroitin may offer modest benefits for some animals with arthritis. Ask your vet whether they suit your dog. For newer findings, read what joint supplement research shows.
Where probiotics fit
Probiotics support a separate discussion about digestion. Read how probiotics fit into gut health.
Colostrum and functional mushrooms
Colostrum and functional mushrooms are sold as dog supplements. Ask your vet whether either fits your dog’s needs. Supplement mushrooms differ from wild mushrooms growing in your yard. If your dog eats a wild mushroom, call your vet immediately.
Are supplements worth it for dogs?
Sometimes, if there’s a clear need and evidence of benefit. The Merck Veterinary Manual advises adding nutrients to complete and balanced food cautiously and only for a clear reason. Tufts veterinary nutritionists recommend questioning claims before buying: look for evidence that the supplement works as labeled and is safe.
How to choose a quality supplement for your dog
Choose a brand your veterinarian recommends or one with the National Animal Supplement Council (NASC) seal, as Cornell's Riney Canine Health Center advises. Then read the label for the maker's contact details and the amount of each active ingredient.
The checks matter because supplements are not regulated like medications, and products may not contain what the label says. Unlike drugs, supplements do not need FDA review of their effectiveness, safety, or quality before they are marketed, explains Tufts Petfoodology. A tablet that should contain 500 mg may contain 500 mg, 1,000 mg, or nothing, and some supplements may be contaminated with mercury, lead, or other substances.
Supplement label checklist
Bring this checklist to the store or use it when shopping online:
- A brand your vet recommends, or the NASC seal.
- The maker's name and contact information, as VCA Animal Hospitals advises.
- The amount of each active ingredient, not only a list of contents.
- Any inactive or carrier ingredients, such as milk, sugar, whey, or proteins.
- For herbal products: the Latin plant name, a harvest or expiration date, the part of the plant used, and the amount of active compounds.
- A lot number and an expiration date on the package.
- Evidence that the product meets its label claim and is safe, which Tufts veterinary nutritionists advise checking before you buy.
- Your vet knows about it, along with every other supplement your dog gets.
Before adding anything new, ask your vet whether it suits your dog, as Tufts recommends.
How long does a supplement take to work in a dog?
It depends on the product and the goal. Glucosamine for arthritis signs may take about four to eight weeks to show its effects, according to VCA Animal Hospitals. A multivitamin is a different case: a healthy dog on a commercial complete food should not need one unless your vet finds a specific health issue.
The table shows when to judge each type and what to watch.
| Supplement type | When to judge it | What to watch |
|---|---|---|
| Multivitamin, for a healthy adult on a complete and balanced food | Usually not needed: Tufts says a dog on a commercial food should not need one unless a specific health issue is found | Ask your vet first |
| Glucosamine, for arthritis signs | After about 4 to 8 weeks, VCA says; the effects take about as long to wear off after it is stopped | The signs your vet asked you to track |
| Probiotics | See how long probiotics take in dogs |
What your vet asks you to track |
| Fish oil | Ask your vet when to judge it | What your vet asks you to track |
Assess glucosamine over weeks, not days. Keep a brief weekly note of the signs your vet recommends watching to help you track changes.
Where a daily supplement fits in your dog's routine
If your vet recommends a daily supplement, choose a form your dog takes easily. Soft chews can be convenient for dogs that refuse tablets. HolistaPet offers multivitamin, colostrum, and functional mushroom soft chews for dogs. Browse HolistaPet's supplement soft chews.
Multivitamin Soft Chews for Dogs contain 30 chews per bag, available singly or in a 2-pack. The colostrum chews pair bovine colostrum with five mushrooms: Reishi, Turkey Tail, Lion’s Mane, Maitake, and Shiitake. The functional mushroom chews combine those mushrooms with vitamin C, astragalus, colostrum, DHA, EPA, and astaxanthin. Both mushroom-containing options come in bags of 30 or 60.
Make chews part of daily wellness care while keeping complete and balanced food as the foundation. Check each ingredient’s amount per chew on the label. Bring the bag to your next checkup so your vet can review it with your dog’s food and other supplements.
Sources
- Tufts University Cummings School of Veterinary Medicine, Petfoodology (Deborah E. Linder, DVM, MS, DACVIM (Nutrition)). What Nutrients are Essential for My Pet? 2023.
- Merck Veterinary Manual (Sherry Lynn Sanderson, DVM, PhD, DACVIM-SAIM, DACVIM-Nutrition). Nutritional Requirements of Small Animals. 2024.
- Merck Veterinary Manual (Sherry Lynn Sanderson, DVM, PhD, DACVIM-SAIM, DACVIM-Nutrition). Dog and Cat Foods. 2025.
- Tufts University Cummings School of Veterinary Medicine, Petfoodology (Cailin R. Heinze, VMD, MS, DACVIM (Nutrition)). When Less is More: Sensible Use of Supplements. 2018.
- Tufts University Cummings School of Veterinary Medicine, Petfoodology (Lisa M. Freeman, DVM, PhD, DACVIM (Nutrition)). Dietary Supplements for Pets: Harmful or Helpful? 2017.
- Cornell University College of Veterinary Medicine, Riney Canine Health Center. How joint supplements can help orthopedic conditions. 2025.
- VCA Animal Hospitals (Know Your Pet). Supplements - Selecting Supplements for Your Pet. 2024.
- Tufts University Cummings School of Veterinary Medicine, Petfoodology (Deborah E. Linder, DVM, MS, DACVIM (Nutrition)). Should I Give Fish Oil to My Pet? 2018.
- Tufts University Cummings School of Veterinary Medicine, Petfoodology (Cailin R. Heinze, VMD, MS, DACVIM (Nutrition)). Should you make your own pet food at home? 2016.
- Tufts University Cummings School of Veterinary Medicine, Petfoodology (Deborah E. Linder, DVM, MS, DACVIM (Nutrition)). Treat options for dogs and cats without unbalancing their diet. 2021.
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