Dogs & Vitamins: Do dogs need them? Vitamin Deficiencies in dogs

feeding dog vitamins

Vitamins are necessary substances that dogs use to complete everyday metabolic functions properly. They are mostly found at low concentrations in the diet and unfortunately many are not synthesized by the body.

With the advent of holistic pet care, many owners are questioning if a dog multivitamin is necessary to achieve optimal health.

Let’s start with the basics, there are two main types of vitamins: water-soluble (does not need to be taken with food) and fat-soluble (should be taken with food). This is important to know when giving your dog vitamins or adding them to their food.

Also, if you are looking for more information about vitamins and minerals for dogs a great book to check out is here, it may be a bit on the scientific side for most but includes basically everything you need to know about feeding dogs and cats.

Should I give my dog vitamins?
Which dogs should have vitamins?
Which vitamins does my dog need?
How do I know if my dog has a vitamin deficiency?
What are some good dog multivitamins?
What not do when starting your dog on vitamins?
Can Dogs take human vitamins?

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There may be many reasons that pet owners decide to supplement their dog’s meals with vitamins, a couple of the most common reasons include

  • Most produce is grown in soil depleted of nutrients and sprayed with pesticides
  • Most meat (unless organic) comes from animals given estrogenlike hormones to make them grow bigger and faster
  • Some animals were administered antibiotics
  • Dogs (just like humans) experience a daily bombardment of pollutants and toxins which can be physical stressors that may increase your dog’s need for vitamins


The main question to ask yourself is if you even need to give your dogs vitamins. The answer depends on what and how you are feeding him or her.

If your pet is eating quality “complete and balanced” over-the-counter commercial dog food, they probably do not need a dog multivitamin supplement as their food should contain all of the vitamins needed.

This is even more so if you are feeding your dog food aimed at specific life states like puppy and senior since these diets often contain a calculated vitamin dose depending on what your dog needs at that time in their life.


Here are some times you may consider supplementing your dog with a multivitamin

If your dog gets homemade meals

Homemade meals are a great, healthy option for your dog since you know exactly what your dog is ingesting and how it was processed. However, you may need to supplement your dog’s meals with vitamins or an overall multivitamin. If you are simply topping your dog’s over-the-counter meals with homemade food this should not be necessary but speak with a veterinary nutritionist to develop a sound feeding plan for your dog to ensure s/he is getting everything they need in their diet.

Something else to consider is the fact that many vitamins may denature with heat, so if you are not feeding your dog a raw diet and are cooking their food they may need vitamin supplementation

Large breed dogs

If you opt not to feed your growing large breed dog puppy food specifically for large breed pups then you may want to supplement their diet with vitamins. Speak with your vet about which vitamins to give your fast-growing pup because if their food contains too many vitamins and minerals, like calcium, it could make them grow too quickly and negatively impact their joints. It is a fine line to walk when feeding puppies which is why most vets recommend sticking with quality commercial dog food that has been formulated for growing dogs.

Pregnant or lactating dogs

Speak with your vet about good vitamins for your pregnant or lactating dog as they will often require more nutrients and minerals than dogs that are not

Vegan Dogs

Yes, there is such a thing, although I’m sure most dogs would prefer not to be vegan if given the option, some pet parents choose to go the route of canine veganism. Dogs are omnivores so they eat meat and plants (as opposed to cats which are carnivores) many of the vitamins vital to their growth, development, and longevity are found in meat which is why vegan dogs need vitamin supplementation

Dogs eating poor-quality diets

If your dog is eating a diet that is of poor quality, they may need supplementation. If you want to read about how to choose a quality dog food read our article all about the subject.

Dogs on certain medications

Some medications like high blood pressure meds and cortisone can interfere with vitamin absorption in dogs and may need supplementation. An example is anti-inflammatories and vitamin D and in some cases, dogs on diuretics (medication to help them urinate) will need vitamin supplementation

Dogs with pre-existing conditions

If your dog has anemia, cancer, or another pre-existing condition that can interfere with the absorption of vitamins, they may need to have vitamin supplementation


Vitamins A, C, K, E, C, and B-complex vitamins are considered essential for dogs because they are needed to sustain life. It should also be noted that the fat-soluble vitamins are stored in the body which creates a greater risk for toxicity but a lower risk for deficiencies. Let’s go over these major vitamins that your dog needs and should be getting from their diet and the risks associated with toxicities and deficiencies.

1. Vitamin A


There are five primary functions of vitamin A vision, growth, cellular differentiation, morphogenesis (the formation of morphology during embryonic development), and immune function.

Clinical signs of a Vitamin A deficiency

Clinical signs of too much Vitamin A

  • Skeletal abnormalities
  • Oversensitivity to sensory stimuli
  • Cleft palpate i puppies
  • Refusal to walk

2. Vitamin D


Vitamin D helps maintain your dog’s body mineral balance and plays an important part in regulating calcium and phosphorous in the body for bone growth

Clinical signs of a Vitamin D deficiency

Vitamin D deficiencies often have to do with bone development and stabilization so signs of a deficiency usually include

  • lameness
  • rickets

Clinical signs of too much Vitamin D

calcification of soft tissues (calcium sticking to the organs)

3. Vitamin E


Vitamin E is an antioxidant present in plasma, erythrocytes, and tissues, where it functions as a scavenger of free radicals and thus, prevents free-radical or oxidative damage.

Clinical signs of a Vitamin E deficiency

  • degeneration of the skeletal muscles
  • muscle weakness
  • reproductive failure
  • retinal degeneration
  • while rare owners may notice edema
  • anorexia
  • depression
  • in severe cases coma

Clinical signs of too much Vitamin E

Dogs given high doses of vitamin E showed relatively few clinical signs as it is known to be relatively nontoxic. However, it may interfere with the absorption or metabolism of vitamins D and K

4. Vitamin K

Fat-Soluble (should be given with food)

Vitamin K plays an important part in activating your dog’s blood’s ability to clot and bone formation

Clinical signs of a Vitamin K deficiency

Signs of a vitamin K deficiency may include increased clotting times in dogs, however, there has not been much research done as naturally occurring vitamin K deficiencies (in the absence of anticoagulants) have not been reported

Clinical signs of too much Vitamin K

There have also been no studies of vitamin K excess in dogs to determine what the detrimental effects would be if any. But vitamin, in general, has not been shown to be toxic to animals

5. Vitamin B

The B-complex vitamins work together as a team and usually come together. The B-complex vitamins help to ward off stress, are essential for cell maintenance and growth, alleviate neurological issues, are needed for the production of antibodies and red blood cells, and the absorption of protein, fat, and carbohydrates.

There has even been one study that showed that hyperactivity and aggressiveness in dogs can sometimes be remedied by a B-complex supplement.

Some drugs like cortisone (a steroid), some high blood pressure medication, sulfa drugs, and hormone therapy drugs rob your dog’s body of vitamin B so be sure to supplement if your dog is taking these.

Water Soluble

There are several forms of vitamin B often referred to as B complex vitamins, all of which help the body to convert food (carbohydrates) into fuel (glucose), which is used to produce energy.

Thiamin (Vitamin B1)

Most clinical signs of thiamin deficiencies are due to changes in the brain such as myelin degeneration and axonal disintegration and can include

  • severe neurological signs (seen in acute cases)
  • heart issues (usually in more chronic cases)

There are no reports of toxicity resulting from oral ingestion of thiamin by dogs, only thiamin hydrochloride


Also known as B2 and occurs in the coenzyme form and its major function is to serve as a precursor of the coenzymes FMN and FAD. Synthesis of the coenzymes from riboflavin is under the control of the thyroid hormones.

Signs of deficiency include

  • anorexia
  • decreased activity
  • hypothermia
  • weight loss
  • slow breathing
  • muscle weakness which worsens over time
  • flaking dermatitis
  • eye opacity

There are no studies that show negative effects of an increased dose of riboflavin in dogs

Vitamin B6

Signs of deficiency include:

  • weight loss
  • death (especially in puppies)
  • convulsions
  • muscle twitching
  • anemia

When an increased dose of Vitamin B6 is given dogs had

  • muscle weakness
  • loss of balance
  • ataxia


Niacin is the general descriptor for vitamins having the biological activity associated with nicotinamide, including nicotinamide, nicotinic acid, and a variety of pyridine nucleotide structures

signs of deficient include

  • anorexia
  • bodyweight loss
  • reddening of the inside of the upper lip that becomes inflamed
  • ulcers in the lip lining
  • excessive salivation
  • bloody diarrhea
  • reduced absorption of water and minerals

Too much Niacin has been shown to lead to bloody feces, convulsions, and death

Pantothenic acid

Is a component CoA and is required by all forms of life. It is widely distributed in foods and deficiencies are rare

If deficiencies occur they can result in

  • coma
  • fas breathing
  • fast heart rate
  • convulsions
  • gastrointestinal
  • signs like diarrhea and enteritis

no cases of pantothenic acid toxicity have been reported

Cobalamin (Vitamin B12)

Cobalamin is unique because it is made by certain microorganisms. The major food sources of cobalamin in the diet are animal products since plant products do not have the vitamin.

deficiency of cobalamin include

  • inappetence
  • failure to thrive
  • neutropenia
  • anemia
  • changes in the bone marrow

There are no reports of toxicity reported from eating high doses of cobalamin by dogs

Folic Acid (Vitamin B9)

  • signs of deficiencies include
  • weight loss
  • anemia

According to the book ‘The nutrient requirements of dogs and cats, there have been no adverse responses to excess folic acid in dogs and it is presumed to be fairly safe.


Biotin, also known as vitamin H is part of the B complex group of vitamins. There are no reports providing many clinical signs of biotin deficiency reported in dogs but alopecia may occur. There are also no reports of biotin toxicity in dogs

6. Choline

Choline is not a true vitamin in the classic sense because many animals can synthesize it in the liver. It is also not considered an essential vitamin but is an integral component of the phospholipid lecithin and is a necessary component of the phospholipid cell membrane. Choline supports healthy brain and liver function and in some cases is given to dogs with epilepsy.

Clinical signs of a Choline deficiency

  • weight loss
  • vomiting
  • fatty liver
  • death

Clinical signs of too much Choline

  • weight loss
  • anemia

7. Ascorbic Acid

Water Soluble

Ascorbic acid or vitamin C is normally synthesized in the liver from glucose and plays a role in hormones and hormone activation. It is a powerful antioxidant that can boost the immune system, reduce the risk of cancer and cataracts, and stimulate wound repair. It is important for proper bone formation and preventing heart disease.

There was a study published in the American Journal of Clinical Nutrition that reported people with cataracts tend to have lower levels of vitamin C in their blood.

Clinical signs of a Vitamin C deficiency

  • muscle weakness
  • joint pain
  • delayed wound healing
  • bone weakness
  • bad breath

Clinical signs of too much Vitamin C

  • Gastrointestinal upset (diarrhea & vomiting)

CHOOSING a good dog food

How do I know if my dog has a vitamin deficiency?

There are several ways to know if your dog has a vitamin deficiency besides paying attention to the clinical signs mentioned above. Most commonly, your vet will run a simple blood test to check your dog’s vitamin levels just like in human medicine. Here are the four main ways vets will check for vitamin deficiency in animals.

1. Blood work: One of the simplest and most common ways of measuring the concentration of vitamins in your dog’s blood work.

2. Urinary measurement: Oral administration of the vitamin to the dog or cat and measurement of the urinary excretion of the vitamin or one of its metabolic products as an index of the saturation of body tissues

3. Measurement of a compound in a biological fluid that requires the vitamin for its metabolism

4. Enzyme stimulation tests: The rate of a reaction is measured before and after the addition of the vitamin

What are some good vitamins for my dog?

There are so many choices for a dog multivitamin in the market but in general, you want a multivitamin that

  • Includes all of the core water and fat-soluble vitamins your dog needs
  • The ranges for each vitamin are within the necessary limits for your dog’s weight (not too low or too high)
  • Have paid for clinical trials or studies to test the efficacy of their vitamins
  • Have raving reviews of other’s experiences with the vitamins prior to

Can dogs take human vitamins?

It is not a good idea to give your dog human vitamins as the supplements made specifically for dogs are formulated with the weight of your dog in mind.

dog multivitamin

Canine Complete Wholistic Vitamins for Dogs

For Dog’s Daily Health: Canine Complete is a premium dog supplement loaded with multivitamins for dogs and a key source of healthy protein; contains vitamins, minerals, prebiotics, probiotics, and more

Per the website, the daily dog vitamin powder features organic ingredients which are easily digestible when mixed into food and is ideal for dogs of all ages; visible results in a few weeks

No fillers, synthetics, GMO or artificial flavoring, only natural ingredients for a healthy functioning digestive system, immune system, and more

dogs vitamins

dog multivitamin
dog multivitamin
dog multivitamin
dog multivitamin
dog multivitamin

Vegetable flavor, calcium carbonate, canola oil, soy lecithin, fish oil concentrate, I-ascorbyl-2- polyphosphate, maltodextrin, sodium
alginate, calcium sulfate, citrus pectin, water, Vitamin E
supplement, di-methionine, vitamin B12 supplement, ferrous sulfate, sorbic acid (a preservative), zinc sulfate, niacinamide, d-calcium,
pantothenate, mixed tocopherols (a preservative), citric acid (a preservative), rosemary extract, silicon, dioxide, vegetable oil,
propionic acid (a preservative), manganese sulfate, inositol, riboflavin, copper, sulfate, magnesium oxide, vitamin D supplement, vitamin A supplement, pyridoxine hydrochloride, sodium selenite,
thiamine mononitrate, biotin, folic acid, potassium chloride, and calcium iodate.

Also, LC Vitamins are very popular with many owners.

Do this prior to starting your dog on a multivitamin

  • Don’t start your dog on vitamins without speaking with your vet first as they can help you choose a good vitamin, give you the appropriate dose, and see if tests need to be run prior to starting your dog on vitamins
  • Don’t feed your dog human vitamins as they will most likely require a different dosage than a human
  • Get your dog’s vitamin base levels this way you can ensure that your dog is getting the appropriate amount of vitamins, you will probably want to check these levels annually

Key takeaways about dogs and vitamins

  • There are only a few vitamins stored in your dog’s body, which means they have to be provided in the diet regularly
  • Different life stages of your pet require different amounts of vitamins
  • Deficiency symptoms vary since each vitamin plays a different role in metabolism (some can take months to appear)
  • Most dogs do not need supplementation with vitamins as most commercially available dog foods have the proper amount. Researchers have determined that there is no chemical difference between synthetic vitamins and those in food

Dog diarrhea colitis