Cobalamin, also known as Vitamin B12, is a vital water-soluble vitamin that is rich in cobalt. It plays a significant role in the body’s biochemical processes, particularly in single carbon transfers. These transfers involve the transfer of functional units like methyl groups (-CH3) onto or between important compounds in the body. Cobalamin acts as a co-factor for three enzymes that facilitate these reactions, making it a crucial carrier of the single carbon group.
The importance of cobalamin in human medicine cannot be overstated. Deficiencies in cobalamin can lead to hyperhomocysteinemia, a condition linked to cardiovascular disease. Additionally, cobalamin deficiency may also cause demyelinating neuropathies, dementia, and megaloblastic anemia (known as pernicious anemia).
In companion animals, cobalamin has gained prominence as a diagnostic marker for gastrointestinal diseases. Studies have shown that cobalamin supplementation is essential for improving the response to therapy for gastrointestinal diseases in animals.
Cobalamin Deficiency in Gastrointestinal Disease
When animals have reduced cobalamin absorption, it’s expected that their cobalamin body stores will eventually deplete, resulting in cobalamin deficiency. This deficiency can contribute to the clinical signs and manifestations of gastrointestinal diseases in some patients. Studies have demonstrated that cats with gastrointestinal disease exhibit a significantly reduced half-life of cobalamin.
While serum cobalamin concentration is used for diagnostic purposes, it is important to note that cobalamin-dependent enzyme reactions occur in the mitochondria. Therefore, assessing the availability of cobalamin in the patient’s body can be challenging. However, tissue-level deficiency can be detected by observing an increase in the urinary and serum concentrations of methylmalonic acid. Cats and dogs with very low serum cobalamin levels indeed exhibit significant tissue-level cobalamin deficiency.
Cobalamin Therapy
The significance of tissue-level cobalamin deficiency in companion animals with gastrointestinal diseases has led to the adoption of cobalamin supplementation as a therapeutic approach. A study conducted on feline patients with severe cobalamin deficiency and chronic gastrointestinal diseases showed promising results. Following parenteral cobalamin supplementation, methylmalonic acid concentrations in serum returned to normal levels, resulting in weight gain and a decrease in clinical signs such as vomiting and diarrhea.
Dogs with exocrine pancreatic insufficiency (EPI) commonly have subnormal serum cobalamin concentrations. Enzyme replacement therapy alone is not sufficient to restore cobalamin absorption in these dogs. Therefore, cobalamin supplementation is essential, as dogs with EPI are at a high risk of developing cobalamin deficiency.
Supplementation of cobalamin is recommended for both dogs and cats with serum cobalamin concentrations in the low normal range. Cyanocobalamin is the commonly chosen form for supplementation, as it is readily available and cost-effective. Further studies are needed to determine the optimal route and dosage for cobalamin supplementation in animals.
Recommendations
In conclusion, we recommend measuring serum cobalamin concentrations in all dogs and cats with chronic gastrointestinal diseases, especially those with a suboptimal response to previous therapies. Cobalamin supplementation should be considered for animals with serum cobalamin levels below the laboratory reference range. Since cobalamin is a water-soluble vitamin, excess supplementation poses no clinical risks.
Stay healthy and don’t forget to check your cobalamin levels regularly for a vibrant, energetic life!
Sources:
- Simpson KW, Fyfe J, Cornetta A, Sachs A, Strauss-Ayali D, Lamb SV, Reimers TJ (2001), Subnormal concentrations of serum cobalamin (Vitamin B12) in cats with gastrointestinal disease, Journal of Veterinary Internal Medicine 15: 26-32
- Vaden SL, Wood PA, Ledley FD, Cornwell PE, Miller RT, Page R (1992), Cobalamin deficiency associated with methylmalonic acidemia in a cat, Journal of the American Veterinary Medical Association 200 No.8: 1101-1103
- Ruaux CG, Steiner JM, Williams DA. (2001), Metabolism of amino acids in cats with severe cobalamin deficiency. American Journal of Veterinary Research 62: 1852-1858
- Ruaux CG, Steiner JM, Williams DA. (2005), Early Biochemical and Clinical Responses to Cobalamin Supplementation in Cats with Signs of Gastrointestinal Disease and Severe Hypocobalaminemia. Journal of Veterinary Internal Medicine 19: 155-160
- Simpson KW, Morton DB, Batt RM (1989), Effect of exocrine pancreatic insufficiency on cobalamin absorption in dogs, American Journal of Veterinary Research 50: 1233-1236
