Vitamin B12
| Category | Biochemistry |
|---|---|
| Test background |
Megaloblastic anaemia is an anaemia (of macrocytic classification) which results from inhibition of DNA synthesis in red cell haematopoiesis. It is often due to deficiency of vitamin B12 and/or folic acid. Mild B12 deficiency is common in older persons, most often resulting from achlorhydria. Severe vitamin B12 hypovitaminosis can also result from a lack of intrinsic factor (autoimmune-mediated) causing pernicious anaemia as a consequence of B12 malabsorption. |
| Clinical Indications |
Demonstrable macrocytic anaemia (as seen in red cell indices) Investigations of suspected subacute combined degeneration of the spinal cord (a deficiency not necessarily apparent in a patient's red cell indices) |
| Reference range | 160-800 ng/L |
| Sample & container required | SST (gold top) |
| Sample volume | 0.5 mL |
| Turnaround time | 1 day |