B12 Deficiency in Cats: The Role of the Gut
Written by Ellen Barber
Published on November 10, 2018, Updated on February 10, 2019
Did you know that vitamin B12 (also called cobalamin) is crucial for your cat’s health? But if your cat suffers from a chronic digestive disorder like inflammatory bowel disease (IBD) or pancreatitis, their body may have trouble absorbing or retaining enough of this nutrient. In a sick cat, symptoms such as lethargy, loss of appetite, vomiting, diarrhea, and constipation may be partly due to B12 deficiency.
Why is B12 Important?
Vitamin B12 is crucial to the health of your cat’s immune system, nervous system, and digestive tract. It’s essential for healthy cognitive function. In addition, B12 assists in your cat’s digestion.
Where Does B12 Come From?
Cats cannot produce their own B12. Cats obtain the vitamin through their diet, and most commercial cat foods provide sufficient amounts of B12 for a healthy cat.
Why Do Some Cats Have a Vitamin B12 Deficiency?
B12 is found in animal products such as meat, liver, fish, and eggs. And cats are carnivores. So you’d think a cat’s diet would contain plenty of B12.
But sick cats may not be able to absorb enough of the B12 that’s in their food. The absorption of this vitamin is a complex process that involves the stomach, pancreas, small intestine, and liver, so if any one of those organs isn’t functioning well, less B12 gets absorbed.
In addition, vitamin B12 only stays in the body for a limited time. In a healthy cat, the tissues retain B12 for an average of 13 days, but in a cat with gastrointestinal disease or other health problems, B12 may stay in the body for only about 5 days. So reserves of this vitamin get depleted quickly in cats and this causes low B12 levels.
Disorders that interfere with the absorption of nutrients, such as inflammatory bowel disease (IBD), can lead to B12 deficiency in cats. Studies have shown that cats with IBD, intestinal lymphoma, and pancreatitis tend to have much lower levels of B12 in their bodies than healthy cats.
What Are the Symptoms of B12 Deficiency?
In cats, not having enough B12 can cause weight loss, lethargy, diarrhea, or vomiting.
Because disorders of the GI tract can interfere with the absorption of B12, the level of this vitamin in the blood is sometimes used as a test of gut health. If your cat suffers from weight loss, lethargy, diarrhea, or vomiting, your veterinarian may measure the level of B12 in your cat’s blood. A low level of B12 in your cat can indicate an unhealthy gut.
Another way to learn more about your cat’s gut health is our at-home KittyBiome Gut Health Test, which provides a detailed breakdown of all the bacteria in your cat’s gut, as well as how they compare to the bacteria in healthy cats. The microbiome test report provides actionable insights for personalized diet and nutrition based on your cat's unique gut microbiome composition.
Can B12 Shots or Supplements Help a Sick Cat?
If your cat suffers from chronic digestive or gastrointestinal problems, oral B12 supplements are unlikely to help. This is because their digestive tissue cannot absorb the nutrient very well, no matter how much they ingest through diet.
However, many cats may benefit from B12 shot injections under their skin. Instead of having to be absorbed by the digestive system, a B12 shot (injection) goes straight to the source. Talk to your veterinarian to find out whether B12 shots are an option for your cat. With instruction, you may be able to give your cat these injections at home.
For cats with chronic digestive issues, unfortunately, there is rarely a single “magic bullet” solution that resolves all of their symptoms. Extra B12 on its own won’t cure IBD in cats or other diseases, but it may help alleviate some symptoms while improving your cat’s overall well-being and quality of life.
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