Overview

• Absorbed in association with intrinsic factor   →   decreased IF   →   decreased absorption of clot   →   low blood concentration.
• Absorbed in ileum   →   malabsorption results in low levels in blood.
• Utilized by small intestinal bacteria   →   GI obstruction   →   bacterial growth   →   bacterial overgrowth reduces levels.

Sampling

Tests

Methodologies

• Radioimmunoassay.
• Chemiluminescent immunoassay.
• Bioassays.

Availability

• Specialist laboratory - must use assay that boils serum/plasma.
• Canine and feline serum may contain binding proteins that need to be denatured and absorbed before measurement via a "charcoal boil" step. Human laboratories may not necessarily carry out this step, by preference use a laboratory that routinely measures vitamin B12 in veterinary species.

Technician (extrinsic) limitations

• Specialized.

Result Data

Further Reading

Publications

Refereed papers

• Recent references from VetMedResource and PubMed.
• Reed N, Gunn-Moore D & Simpson K (2007) Cobalamin, folate and inorganic phosphate abnormalities in ill cats. J Fel Med Surg 9, 278-288 PubMed.
• Simpson K W, Fyfe J, & Cornetta A et al (2001) Subnormal concentrations of serum cobalamin (Vitamin B12) in cats with gastrointestinal disease. JVIM 15, 26-32.

Other sources of information

• Simpson J W (1998) Gastrointestinal system and exocrine pancreas. In: Manual of Small Animal Clinical Pathology. Eds: Davidson M, Else R & Lumsden J. BSAVA, UK.
• Bush B M (1991) Interpretation of Laboratory Results. Blackwell Scientific Publication, UK.