B-Complex Vitamins for Dogs

Written By Emily Gantt
Published: 03/17/2021Updated: 03/17/2021
B-Complex Vitamins for Dogs

What two things do niacin, riboflavin, and pantothenic acid have in common? They're all B-complex vitamins, and they're essential for both dogs and humans.

B-complex vitamins play many roles in a dog's body, from giving them energy to keeping their teeth healthy ‚ÄĒ but that's just the beginning. We'll delve into the function of these vitamins, how to know if your dog has a deficiency, and give you the facts on supplementing if your dog needs more.


Each vitamin (and there's a lot of them!) within the B-complex category have different functions in the canine body, and they affect nearly every body system. Here's what they do:

Thiamine (vitamin B1)

  • Needed for the body to break down carbohydrates

  • Strengthens the body's immune response

  • Important for brain function

Riboflavin (vitamin B2)

  • Works closely within the muscle system to maintain strength

  • Supports eye health

  • Plays a role in red blood cell production

Niacin (vitamin B3)

  • Helps with the digestion and the metabolism of fatty acids¬†

  • Promotes brain function

  • Catalyst for hormone productions

  • Aids in the production of corticotrophin-releasing hormones.

Folic acid (vitamin B9)

  • Used in red blood cell production

  • Essential for DNA synthesis

  • Is important for the development of healthy embryos during pregnancy

Pantothenic acid (vitamin B5)

  • Necessary for the body to make proteins and fatty acids

Biotin (vitamin B7)

  • Important for healthy skin and fur

Pyridoxine (vitamin B6)

  • Regulates sodium and potassium levels in the body

  • Promotes healthy cognitive function

  • Important for erythrocyte production

Cobalamin (vitamin B12)

  • Affects nerve function

  • Essential for the production of myelin, which coats the nerves

Daily Recommended Intake

Below is the daily recommended intake of B-complex vitamins for a healthy 30-pound dog. Keep in mind that every dog is different, and some may need more or less vitamins depending on their activity level and any conditions they may have. Talk to your vet about specific daily requirements for your dog's size and breed.

Daily recommended intake of B-complex vitamins for a 30-pound dog is as follows:

  • Thiamine: 0.56 mg/1,000 calories

  • Riboflavin: 1.3 mg/1,000 calories

  • Niacin: 4 mg/1,000 calories

  • Folic acid: 68 micrograms/1,000 calories

  • Pantothenic acid: 4 mg/1,000 calories

  • Biotin: 7 mg/1,000 calories

  • Pyridoxine: 0.4 mg/1,000 calories

  • Cobalamin: 9 micrograms/ 1,000 calories

Food Sources

Kibble is a dog's number one source of B-complex vitamins, but even that isn't perfect. B-complex vitamins are light-sensitive and can quickly denature. For this reason, you should keep your pet's food in its original packaging, away from light sources or heat, to maximize the vitamin's potency. 

So where else can dogs get the B-complex vitamins if their food isn't fitting the bill? Here are some dog-safe human foods that are excellent sources of B-complex vitamins:

  • Beef liver

  • Milk

  • Leafy greens

  • Eggs

  • Chicken¬†

  • Oats

  • Fish

  • Beans

Signs of B-Complex Vitamin Deficiency in Dogs

Symptoms of B-complex vitamin deficiency vary depending on which vitamin the dog is deficient in. Some of these symptoms are pretty unique and are easy to diagnose (like the black tongue, which is a classic sign of a niacin deficiency). Other symptoms of B-complex vitamin deficiencies aren't as distinct and make it more difficult to pinpoint the exact cause. Here are the signs of B-complex deficiency by vitamin. 

Signs of a thiamine deficiency:

  • Absent reflexes

  • Anorexia

  • Muscle weakness

Signs of a riboflavin deficiency:

  • Stunted growth

  • Decrease in strength

  • Poor eyesight

  • Weakness of the back legs

  • Heart problems

Signs of a niacin deficiency:

  • Darkening of the tongue

  • Swelling of the mouth

  • Anorexia

  • Blood in the stools

  • Bad breath

Signs of a folic acid deficiency:

  • Low hemoglobin¬†

  • Fatigue

Signs of a pantothenic acid deficiency:

  • Bald patches

  • Change in fur color

  • Loose stools

  • Stomach upset

Signs of a biotin deficiency:

  • Dull coat

  • Skin sores

  • Muscle weakness or paralysis

Signs of a pyridoxine deficiency:

  • Low hemoglobin

  • Skin sores

  • Tooth decay

  • Kidney stones

Signs of a cobalamin deficiency:

  • anorexia
  • lethargy
  • weight loss
  • foul-smelling diarrhea

Signs of B-Complex Vitamin Overdose in Dogs

Unlike vitamins A and D, which are fat-soluble and stay in the system for long periods, B-complex vitamins are water-soluble and easily eliminated from a canine's body.

Overdose of B-complex vitamins is virtually unheard of since the high water-solubility means your dog will pee out whatever their body can't use. Dogs can, however, react to very high doses of niacin, which may cause liver damage and skin sores if the dosage is high enough. The only other B-complex vitamin that dogs can overdose on is pyridoxine. 

A study of Beagles given extremely high doses of pyridoxine had a loss of muscle control, low red blood cell counts, and presented cognitive changes. It's important to mention that there is little data on niacin and pyridoxine overdoses outside of experimental settings.

B-Complex Vitamin Supplements for Dogs

Sometimes kibble isn't enough to satisfy a dog's vitamin needs, so pet parents turn to supplements to give their dogs an extra boost. But what does B-complex vitamin supplements do for dogs exactly?

One of the more apparent side effects of B-complex vitamin supplements in dogs is a healthier, shinier coat. Pups with skin conditions may experience clearer skin, less itchiness, and a reduction in inflammation when taking B-complex supplements. Some dogs get an energy boost when taking B-complex vitamins, specifically from extra vitamin B6.

When supplementing, it's important to remember that healthy dogs receiving a nutritionally complete kibble probably won't show much difference since kibble is made with a vitamin blend to satisfy all of a dog's nutritional needs. Dogs that show progress from supplements are usually those with vitamin deficiencies or pre-existing illnesses, like dermatitis.

When choosing a B-complex vitamin supplement for your dog, make sure you're picking one that's made for canines. These formulations are specific to dogs' nutritional needs, and some even come in lots of tasty flavors to make administration easy. You can find B-complex vitamins for dogs in powders and liquids that you can mix in with food or capsules that you can conceal in treats. Most canine multivitamins contain B-complex vitamins as well as other vitamins and minerals your dog needs, like vitamin D and zinc.

As you can see, B-complex vitamins run the gamut as far as effects on bodily processes, from helping eyesight to helping the body synthesize DNA. Without B-complex vitamins, dogs can quickly decline, but these vitamins' susceptibility to light can make getting them in your dog difficult. For this reason, some pet parents choose supplements.

While it might seem like a good idea, refrain from giving your dog B-complex vitamins made for humans; these are too strong for canines, and while overdose is unlikely, it's still not worth the risk.

Considering giving your dog nutritional supplements? Get an expert opinion first. Chat live with a vet now! 

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