Science on Vitamin K for Dogs AnalysisThere are some claims on the benefits of Vitamin K for dogs being thrown around in the pet community.

However, majority of pet owners have never even heard about Vitamin K.

Outside of some unjustified scare that Vitamin K3 has been receiving recently, general Vitamin K is an underappreciated nutrient that doesn’t receive enough attention.

When it comes to using Vitamin K for dogs, its powerful effects may have a significant impact on pet’s health.

Giving Vitamin K1 for dogs has shown to improve their liver and blood health. Vitamin K2 showed positive effects on heart and bone-related diseases.

We’ve previously broken down the benefits and side effects of a more popular Vitamin C for dogs.

In this article, we’ll look at the benefits and side effects of Vitamin K for dogs, and shed some scientific light on the mysterious nutrient.

 

What is Vitamin K?

Vitamin K is praised by some as the super-vitamin for humans and animals alike [1].

Vitamin K exists in two natural forms: K1 (phylloquinone) and K2 (menaquinone). For the purpose of this article, Vitamin K1 and K2 are the “medication,” and Vitamin K is a general term.

Synthetically manufactured forms also exist: K3, K4, K5. Some of them have shown toxicity but only at high dosage levels.

Vitamins K1 and K2 have been proven to be non-toxic [2].

Vitamin K is a fat-soluble vitamin that is necessary to a dog’s overall health [3], and especially as effective coagulant [4].

It was first discovered in 1929 to fight blood clotting/coagulation, and it was called Koagulationsvitamin in a German medical journal [5]. This explains the “K.”

This vitamin can be found naturally in a wide variety of dog-friendly foods, such as cabbage, egg yolks, broccoli, and spinach.

Most commercial dog food diets provide proper amounts of Vitamin K1 for dogs.

A dog’s body can produce its own Vitamin K2 using gut bacteria, but supplementation can be helpful to ensure healthy dog nutrition as long as it has been discussed with a vet beforehand.

Bottom Line: Vitamin K exists in two natural forms, K1 and K2, both of which have different functions. Vitamin K first became known for its definite benefits on blood clotting.

How Does Vitamin K Work in Dogs?

Vitamin K for Dogs and Dental Health

Functions of Vitamin K for dogs are similar to those in humans [6].

One of its crucial jobs is in assisting calcium to strengthen dog’s bones, teeth and other biological processes [7, 8].

This is why Vitamin K for dogs can be very useful if a pet is at risk of osteoporosis or related diseases [9, 10].

Vitamin K1, K2 and K3 all function differently [11, 12]. K1 and K2 are important for closely related body processes.

Vitamin K1 is responsible for activating calcium-binding properties of proteins in your dog’s body, which helps with blood clotting.

Vitamin K2 regulates the appropriate amounts of calcium throughout the dog’s body, like parking enforcement. Studies have shown a lot more potential benefits of Vitamin K2.

Benefits of Vitamin K1 for Dogs

Vitamin K1 (phylloquinone) is known to be non-toxic and has effects that are slightly less impactful than those of Vitamin K2 [2].

When compared to naturally produced K2, Vitamin K1 benefits are not as varied and mostly focused on calcium regulation, bone density and blood health [13, 14].

Its main benefits include potential prevention of osteoporosis in dogs [15].

Vitamin K1 also assists with blood coagulation and preventing arterial calcification [16].

It can also assist in cases of hypoprothrombinemia when there’s an increased physiological risk of bleeding [17].

Vitamin K1 supplements are commonly used when a dog swallows rat poison or any other anticoagulant medicine [18, 19, 20, 21, 22, 23].

Bottom Line: Using Vitamin K1 may help with preventing osteoporosis, osteoarthritis and several blood-related diseases in dogs, but more research is required. Vitamin K1 is the first solution to help dogs who swallow rat poison or other anticoagulants.

Benefits of Vitamin K2 for Dogs

Vitamin K1 for Dogs and Heart HealthSeveral studies on dogs and rats have concluded that Vitamin K2 (menaquinone) has low to no toxicity, and is safe to use [2, 24].

Overall, research with canines is seriously lacking on the effects of Vitamin K2, specifically.

Vitamin K2 is a far more popular vitamin among people when compared to K1, which is why there’s a lot more human trials using Vitamin K2.

When it comes to research, dogs are physiologically similar to humans in some respects [25], thus we’ll have to use studies with people for this part to further speculate on all negative and positive effects of Vitamin K2 for dogs.

Vitamin K2 for heart disease

Vitamin K2 may help to prevent heart problems by averting calcium deposits in arteries [26].

Calcium is one of the primary suspects for creating build-ups around the heart which is a risk factor for heart failure [27, 28, 29].

In human trials, people who took Vitamin K2 were at 57% lower risk of dying from heart disease and at 52% less of a risk for artery calcification [30].

More observational studies have found that regular Vitamin K2 intake may equal lower risk of heart failure [31].

Vitamin K2 for bone health

Osteoporosis is a very common problem in Western societies. Its occurrence has also been found in dogs [9, 25, 32].

Vitamin K2 was shown to help with building and maintenance of bones [33, 34].

There’s also some evidence on how Vitamin K2 has benefits for overall bone health and density [35].

There was also an association with reduction of fractures, particularly in hips and spine [36].

Further studies continue to recommended Vitamin K supplementation for general bone health and osteoporosis [37].

Vitamin K2 for dental health

Teeth are closely related to overall bone health both in dogs and humans.

Although research is still lacking, it only makes rational sense that if Vitamin K2 has benefits on bone health, then it would also has effect on dental health.

Vitamin K2 activates and positively affects bone metabolism through osteocalcin [38].

Osteocalcin is a main regulating protein in dental health. It stimulates growth of new dentin on teeth [39, 40].

Combining Vitamin K2 with Vitamins A and D can have further positive effects on dental health [41].

Vitamin K2 for cancer

There has been some suggestions that administration of Vitamin K2 supplements can help with different types of cancer.

An observational study has found a link between Vitamin K2 and a 63% risk reduction in prostate cancer [42].

A few clinical trials suggest that Vitamin K2 can increase chance of survival and reduce recurrence of liver cancer [43, 44].

More studies are still needed on this effect of Vitamin K2.

In conclusion on Vitamin K studies

It’s clear that there are some definite benefits from using Vitamin K2 and Vitamin K1 for dogs and humans.

However, there are two things pet parents have to keep in mind.

First, some of these are human studies (especially those on K2) and, even though they might, do not necessarily apply to dogs.

Second, more research is needed to make final conclusions on some major benefits and side effects of both Vitamin K1 and K2. Some studies have concluded that current research isn’t clear enough on certain aspects [45, 46].

Bottom Line: Vitamin K2 assists with heart disease, dental health, bone density and cancer. However, more studies are needed, particularly with canines.

Causes of Deficiency of Vitamin K in Dogs

Vitamin K1 for Dogs and DeficiencyThere are specific conditions that may potentially cause a deficiency of Vitamin K in dogs, as well as bleeding disorders.

A dog’s body typically produces Vitamin K all on its own, but there are specific conditions that may potentially cause for dogs to stop producing it or not produce enough.

Common causes of Vitamin K deficiency in dogs are liver problems, which may result in lack of vitamin absorption.

Furthermore, if a dog consumes drugs with certain substances such as warfarin or other anticoagulants, such as rat poison, it can also cause deficiency.

Liver problems

Once taken by mouth or in food form, Vitamin K is absorbed through the dog’s gastrointestinal tract.

Vitamin K1 specifically is absorbed in the presence of bile salts and pancreatic secretions.

Bile salts are made by the liver, and if the liver or gall bladder is diseased, these salts may not be present for proper Vitamin K1 absorption.

Rat poison

Anticoagulants, such as rat poison, or medications containing warfarin, can cause a Vitamin K deficiency in dogs [18-23].

Rat poison causes the rats (or other mammals) to die by inhibiting Vitamin K’s role in blood clotting.

This also ties back into the liver. The liver needs Vitamin K in order to make these clotting factors in the first place.

Digestion

Digestive disorders, especially those that involve fat absorption, can also cause Vitamin K deficiencies in dogs.

In rare cases, a diet severely restricted in fat can lead to Vitamin K deficiencies in dogs.

Antibiotics

It shouldn’t be surprising that antibiotics can contribute to Vitamin K deficiency.

Dogs are being prescribed antibiotics for many different diseases, sometimes even when there’s no reason to do so [47, 48].

A growing body of research has demonstrated how antibiotics lower Vitamin K levels [49, 50] as well as levels for other essential nutrients.

Bottom Line: Vitamin K deficiency in dogs can be caused for multiple reasons: antibiotics, poor digestion/absorption, poisoning or liver problems.

Dog-friendly Foods Rich in Vitamin K

Vitamin K Rich Foods for DogsThere are some foods rich in Vitamin K that are absolutely safe for dogs.

Muscle meat, and particularly liver and other organs of grass-fed cows have been shown to be good sources of Vitamin K, and particularly K2 [51, 52].

Animal products will not contain a lot of Vitamin K2 since it’s a fat-soluble vitamin.

Another plus on the case of probiotics for dogs: studies show that fermented foods have more subtypes of Vitamin K2 [53].

Most of Vitamin K2 dogs get from their gut bacteria, as long as the process hasn’t been hindered by antibiotics or other deficiency-causing cases.

Vitamin K1 is normally found in plant-based foods:

  • Spinach
  • Broccoli
  • Cabbage
  • Asparagus
  • Kale

Supplementation of Vitamin K2 and Vitamin K1 for dogs, as noted below, is also available when that’s necessary.

Using Vitamin D alongside your K may prove even more benefits due to their synergistic effects [54].

Bottom Line: Vitamin K2 is normally produced by gut bacteria, and probiotics can help with that. K2 can also be found in liver. It’s best to use plant-based foods to provide Vitamin K1 for dogs.

Buying and Using Vitamin K for dogs

Vitamin K for Dogs and How to Give Vitamin K1 for dogsSpecific form of Vitamin K supplement is usually prescribed by veterinarians to dogs that are suffering from liver problems, or other disease mentioned above.

Dogs that consume rat poison will also be given an emergency dose of Vitamin K1.

Where to buy: It is important to know that either form of Vitamin K is not available as an over-the-counter dog supplement, and it is required that these vitamins are prescribed only by a veterinarian.

Vitamin K2 in particular, while not toxic, can still be dangerous if given in ultra high doses, thus supervision is essential.

Absorption: Vitamin K for dogs is often available in pill form, which will take up to 24 hours to begin producing the substances that encourage the proper coagulation of blood.

New studies suggest that Vitamin K in gelatin capsule form may have the best absorption [55].

Bioavailability of Vitamin K1 for dogs has shown to be the best when given on an empty stomach; however, it’s not the safest method, thus giving Vitamin K with food is a less effective yet safe option [56].

If a dog is experiencing with several bleeding cases that cannot be stopped, do not attempt to deal with this using supplementation. Such cases will most likely require a full plasma transfusion that will coagulate proteins in order to effectively stop the bleeding.

Dosage: The dosage amount of Vitamin K will be determined by the veterinarian, depending on the dog’s body weight, age, and overall health.

The length of the treatment also varies depending on the severity of the issues present.

Bottom Line: Although Vitamin K1 and K2 supplementation can be safe, it’s best to consult with a veterinarian for proper doses and timing of administration.

Side Effects of Vitamin K

Side Effects Vitamin K for Dogs

When using Vitamin K for dogs orally and as suggested by the veterinarian, it’s unlikely that your dog will experience any serious adverse effects [57, 58, 59].

However, some minor side effects of Vitamin K may occur.

For example, Vitamin K side effects could include a low red blood cell count and skin rashes.

Diarrhea and vomiting may also occur during the initial days of administration as your canine’s body gets used to this supplement.

Research also shows that there’s no risk of thrombosis from using Vitamin K supplementation, and in general, it has been concluded that Vitamin K is safe to use [60].

Note that administration of Vitamin K1 for dogs may interfere with other prescription drugs, such as antibiotics, thyroid medication, Cimetidine, and aspirin.

It should never be supplied intravenously or through injections, because the dog may develop a severe allergic reaction or, in some rare cases, anaphylaxis [61, 62, 63, 64].

Bottom Line: Some studies have shown adverse effects of Vitamin K2 when given in extremely high doses. However, most research points that Vitamins K1 and K2 are both safe to use when properly administered.

Take Home Message

Vitamin K may be the great omnipotent vitamin our dogs have been missing, but more research is required.

Vitamin K1 has positive effects on blood coagulation, osteoporosis, bone and coronary health. It is also the primary medication to fight the adverse effects of rat poison or other anticoagulants.

In human studies, Vitamin K2 has been shown to help with heart diseases, bone and dental health, and even cancer.

With that being said, it is not a dog health supplement that should be given to pets without consulting with a vet.

If you are concerned about your dog’s Vitamin K intake, consider feeding Vitamin K rich foods and talk to your vet about the necessary dog supplements.

When suspecting a serious case, test your dog to find out whether there’s any Vitamin K deficiency and address the issue accordingly with your veterinarian.

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