Serum Cobalamin (Vitamin B12) and Folate

Reference Interval

Cobalamin Folate
Canine 251 – 908 ng/L 7.7 – 24.4 µg/L
Feline 290 – 1,500 ng/L 9.7 – 21.6 µg/L

Turnaround: 2-3 business days after receipt of samples.

Cobalamin: Absorbed in the distal small intestine (specifically in the ileum). Values below the control range are often seen in patients with EPI, bacterial overgrowth in the upper small intestine, or disease affecting the distal small intestine. There is no known significance of values exceeding the control range.

Pancreatic function should be evaluated in dogs and cats with cobalamin deficiency as cobalamin absorption is dependent on exocrine pancreatic function.

Folate: Absorbed in the proximal small intestine only. Values above the control range are consistent with bacterial overgrowth in the upper small intestine. Values below the control range are consistent with disease affecting the proximal small intestine.

Note: Dietary deficiency of cobalamin and folate is highly improbable and even starvation of several weeks duration does not cause serum cobalamin and folate to become subnormal in dogs. Therefore, subnormal serum concentrations of cobalamin reflect a state of chronic malabsorption and should be treated ( cobalamin treatment protocol). Folate supplementation recommendations can be found on the folate supplementation page .

However, not all intestinal diseases causing malabsorption of vitamins are sufficiently severe or long-standing to deplete body stores of each vitamin. Therefore, not all dogs and cats with intestinal diseases have abnormal test results. Also, not all dogs with intestinal disease have intestinal morphologic abnormalities.

Storage Requirements:

Serum folate shows limited stability at room temperature. Therefore, serum samples for folate analysis should be kept in a refrigerator (4°C) for no longer than 48 hours. If samples are being held for more than 48 hours, serum can be stored frozen at -20°C for up to 1 month.