Specimen

3 mL (1 mL min.) Serum from 1 SST. Ship refrigerated or frozen. Wrap in aluminium foil to protect from light. Overnight fasting is preferred.

Usage

Vitamin B12 is necessary for hematopoiesis and normal neuronal function. B12 deficiency may be due to lack of intrinsic factor secretion by gastric mucosa (gastrectomy, gastric atrophy) or intestinal malabsorption (ileal resection, small intestinal diseases) leading to Macrocytic anemia. This assay is useful for investigating Macrocytic anemia and as a workup of deficiencies seen in Megaloblastic anemia.