Vitamin B12 Deficiency in Cats: The Basics

Lisa Selvaggio
by Lisa Selvaggio

Like humans, cats can develop a vitamin B12 deficiency. This water-soluble vitamin is needed for a variety of functions, affecting everything from their digestion to cognitive function, so it’s important to address a deficiency in your pet.

Here’s some information on the symptoms and causes of vitamin B12 deficiency, along with what you can do to address it.


What Are the Symptoms of Vitamin B12 Deficiency in Cats?

In cats, vitamin B12 deficiency can cause symptoms that include the following:

Bear in mind that although a lack of vitamin B12 in the system can lead to these symptoms, various conditions can also cause the same symptoms as vitamin B12 deficiency. So, have your cat examined by a veterinarian if they start exhibiting these signs. Your vet will work on figuring out if your cat has a B12 deficiency, and the cause of that deficiency, so proper treatment can be administered. 

What Can Cause Vitamin B12 Deficiency in Cats?

Healthy cats are able to get enough of this vitamin from their carnivorous diet. But if there is a problem in the digestive system, the vitamin may not be absorbed properly. And with improper absorption, the body’s reserves of the vitamin will decrease. That’s when a deficiency can occur.

Several conditions could lead to B12 deficiency, such as:

Once the cause of your pet’s symptoms is determined, your veterinarian can recommend a treatment plan, which may include B12 supplementation to tackle the deficiency. In fact, treatment might be more effective if it includes supplementation. 

How Is Vitamin B12 Deficiency in Cats Diagnosed?

Your veterinarian can run a blood test to check the amount of vitamin B12 in your cat’s body and determine if there is a deficiency. You may need to fast your cat prior to their examination, so be sure to discuss this with your veterinarian in advance. 

What Is the Remedy for Vitamin B12 Deficiency in a Cat?

If your veterinarian determines that your cat is deficient in vitamin B12, they can prescribe a B12 supplement in the form of a subcutaneous injection or oral supplement. Discuss the pros and cons of each option with your vet so you can decide what’s best for your cat.

Your veterinarian will also give you a dosing schedule that you’ll need to follow to ensure you get the best results. For example, if you opt to give your cat the injectable form of B12, you may be told to give it once a week for four to six weeks before giving it monthly. On the other hand, an oral supplement would have to be given daily.

In addition, your vet will tell you when they plan on running the blood test again to see if the supplementation worked and if it needs to continue. Keep in mind that it can take time, such as several weeks, for a deficient cat to have the right amount of B12 in their body again. 

Don’t forget to tell your vet about any medications or supplements that your cat is taking, as you’ll want to be sure there won’t be any interactions with the B12 supplement.

Supplementation with B12 is considered safe for cats, and there typically aren’t any side effects. The body will remove any excess of the vitamin through the urine. Of course, you’ll still want to keep an eye out for side effects and report them to your veterinarian right away.

Vitamin B12 Supplements You Can Buy for Your Cat

The injectable form of B12 is prescribed by a veterinarian, but you can also talk to them about over-the-counter supplements that are given to cats orally, and the two forms of B12 available: cyanocobalamin and methylcobalamin. That way, you can make the right choice for your pet.

Here are a couple of options to consider: 

Jackson Galaxy B12 for Cats Dietary Supplement

You can use this liquid form of methylcobalamin, a non-synthetic form of the vitamin, to give your cat their daily dose of B12. According to the manufacturer, this form is more easily absorbed when taken orally compared to cyanocobalamin. And it can be given to senior cats who may not be able to absorb this vitamin as well as they used to.

You can add this flavorless liquid to your cat’s food or water. Use the dropper to measure the right amount, following the dosing instructions on the label. Be sure to keep this product refrigerated after opening it.

Nutramax Cobalequin Cobalamin Supplement

This vitamin B12 supplement for cats comes in the form of a chewable chicken flavored tablet, so you can give it to your kitty as a treat or as part of their meal. You can also crush each tablet and add it to their food if that makes things easier.

The nice thing about this product is it doesn’t only contain B12—giving one tablet each day will give your pet a dose of cyanocobalamin and folate, which is another B vitamin that can become deficient. 

Talk to Your Vet About Vitamin B12 Deficiency

Ensuring your cat has adequate levels of vitamin B12 is critical, and the only way to know for sure is a blood test. If your cat is showing signs of deficiency, talk to your vet, who can guide you when it comes to choosing the right supplement that will deliver the best results.

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Lisa Selvaggio
Lisa Selvaggio

Lisa Selvaggio is a freelance writer and editor, and our resident cats-pert, with certifications in pet nutrition and pet first aid. She enjoys producing content that helps people understand animals better so they can give their pets a safe and happy home.

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