Can I Give My Dog Human Vitamin B Complex?

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If you’re a healthy adult who’s somewhat fit or at least generally active, you might have a bottle of two of multivitamins lying around the house.

It’s completely normal for us to pop a chewable vitamin in the morning or before bed, but what if we give human vitamins to our dog too?

Is it okay to give them vitamins or are we causing more harm than good?

While some people say that vitamins are bad for dogs, there are some pet parents who give Vitamin B complex to their pooches?

Are they helping their dog or causing more harm?

Can I give my dog human vitamin B complex? 

No, it is generally a bad idea for you to give your dog human vitamin pills because of the difference in dosage. Your dog needs a lot less than the amount of vitamins that is in a human vitamin pill. If the time comes that your dog actually needs supplementary vitamins, let your vet make a prescription to ensure the correct and safe dosage for your pet.

However, if there is a vitamin that your dog may not fully get from good quality dog food, it is Vitamin B complex. While most good dog food varieties have the complete set of vitamins for your pet, the Vitamin B complex is fragile and can easily be destroyed by heat, exposure, light, and air. What this means is that if the dog food has been in the doggie bowl for a while or if it hasn’t been stored properly, the Vitamin B complex content is probably gone.

What happens if a dog doesn’t get enough Vitamin B complex? This vitamin is in charge of promoting a biochemical reaction that helps transform your dog’s carbohydrate intake into glucose which is a basic form of energy. Your dog will experience weakness and lethargy as well as other symptoms such as sudden weight gain, excessive shedding, decaying teeth, and increased cholesterol levels. 

If you suspect that your dog may be experiencing Vitamin B complex deficiency, contact your vet and arrange a checkup. When your dog is on antibiotics, it is also likely that he will be prescribed Vitamin B complex to go with it.

Can you give your dog human vitamins?

As it turns out, while some dogs do require vitamin supplements for specific cases (and not all dogs in general), these supplements have to made especially for dogs. To make a long story short, you cannot give dogs human vitamins.

What’s the danger of just taking a tablet or two from your own vitamins stash and giving it to your pet, you might ask.

We found out that if you give dogs too much vitamins – Vitamin A and Vitamin D in particular – can cause vitamin toxicity in pets. But vets say that dogs need vitamins too so why does giving them vitamins hurt them?

Dogs have a much lower daily need for vitamins than humans do. Most dog food that you’ll find actually supplies them with their dietary vitamin needs (those that are labeled ‘complete and balanced’), and they only contain about 20% to avoid vitamin overdose. A human vitamin tablet contains 100% of their daily vitamin requirement which will bring them dangerously close to a toxic reaction.

What are the differences between human vitamin pills and dog vitamin pills?

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The main difference between human vitamin pills and dog vitamin pills is balance and content. You will see a lot of articles online that say that dogs need Vitamin D, Vitamin A, Vitamin C, and so on and they’re not wrong. The problem is how much of the vitamins they actually need.

Vitamin D is particularly problematic when it comes to giving dogs vitamin pills meant for humans. Vitamin D or D3 is essential for dogs because, unlike humans, they don’t make their own and they need it for calcium absorption. However, while too little is definitely bad, too much of Vitamin D is even worse.

There’s just too much Vitamin D in human vitamins than is recommended for dogs. Studies show that with a dose as low as 0.5mg per kilo, dogs exhibited vitamin toxicity with symptoms that included vomiting, acute renal failure, polyuria (urinating too much), hyperphosphatemia (calcium deposits on the tissue, causing muscle spasms), and so on.

Generally, if your dog is eating good quality dog food, than he should be getting all the vitamins that he needs. There is no need to give your pet supplementary vitamins unless your vet prescribes it.

What do vitamins do for dogs?

Vitamins are essential to dogs just as much as they are essential to human beings. And just like with humans, they play different yet vital roles in the dog’s body and good health.

  1. Vitamin A – Similar to its role for humans, vitamin A also responsible for eye care and health in dogs. Other than that, it also plays a role in growth and development, fetal growth, cell function, and is important for a dog’s immune system.
  1. Vitamin B complex – As we mentioned above, vitamin B complex plays the important role of converting carbohydrates to glucose, making it essential for a dog’s energy production. Unlike vitamin A and vitamin D, vitamin B complex is water soluble which makes it more fragile and easy to flush out of the body.
  1. Vitamin D – Also considered the sunshine mineral for dogs, vitamin D helps our pets to absorb calcium and phosphorus for healthy bone development and growth. When there’s not enough vitamin D, your dog might start to have problems with bone and muscle health. 
  1. Vitamin C – Ever heard of antioxidants? That’s what vitamin C does for dogs. It removes harmful free radicals that cause sickness and mutations in growth. It also helps reduce inflammation and dementia in dogs. Dogs are not likely to need supplements for vitamin C because they can synthesize it in their liver, but there are still unusual cases where your vet may prescribe some for your pet.
  1. Vitamin K – Vitamin K is in charge of helping your dog’s blood clot in cases of cuts or wounds. In cases when a dog has ingested a poison for rats, this can inhibit the vitamin K and stop your pet’s blood from clotting.

Does giving human vitamins for dogs have any side effects?

Yes, giving human vitamin pills to dogs can have severe side effects.

Because the vitamin dosage for humans are much higher than dogs, giving your dog human vitamin pills poses a legitimate risk of overdose. We’ve already touched a bit on what can happen if your dog ingests too much vitamin D, which is a fat-soluble vitamin so it will take hours to flush out of your dog’s system.

Another common culprit for dog vitamin overdose is vitamin A. Vitamin A toxicity is common in dogs because it is contained in a common human vitamin supplement namely fish oil capsules. While fish oil capsules are great for humans, there is a common misconception that it will also improve the lustre and look of a dog’s hair. The worse thing about too much vitamin A for dogs is that it stays in their liver practically forever (it is also fat-soluble) and can have very long term effects for your pet.

Some of the damage that vitamin toxicity can cause in dogs is irreversible. We highly recommend that you visit your vet before buying any vitamin supplements for your pet, even for those that are designed for dogs.

What is a good source of vitamin B complex for dogs?

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If you are feeding your dog good quality dog food, it is likely that he is already getting his daily needed dose of vitamin B complex. Just make sure that your dog food is properly stored and not exposed to light or air because vitamin B complex is fragile and is easily destroyed by exposure.

Here’s a trick that most pet owners don’t know – sometimes, if your dog is lacking some vitamins, particularly vitamin B complex, your vet will recommend feeding your dog fruits and vegetables. And the fruit that is rich in vitamin B complex that’s also safe for dogs is… bananas. However, since bananas are sugary, it should be saved as a treat instead of being part of your dog’s regular diet.


It’s important to remember that while dogs need vitamins to stay healthy too, the dosage of human vitamin pills is much too high for dogs and can lead to vitamin toxicity. That’s why it’s important to never give human vitamin pills to our pets and to always consult a veterinarian before giving any kind of supplements and medications to dogs – even those that seem completely harmless. 

If you feel that your dog is exhibiting symptoms for vitamin deficiency, specifically vitamin B complex deficiency, our only recommendation is that you consult your vet immediately.