Sample stability:
-
2 hours at 15-25 o C
-
48 hours at 2-8 o C
-
56 days at -20 o C
Units: pmol/L
Reference interval: 170 - 800
The borderline range between 110 - 170 pmol/L is of uncertain clinical significance.
Conversion: pg/mL x 0.74= pmol/L
Uncertainty of Measurement: 10%
Principle: Competitive type immunoassay with chemiluminescence detection
Reagents: Roche Vitamin b12 II
Analyser: Cobas e801
The major fraction (>80%) of plasma vitamin B12 is bound to haptocorrin (transcobalamin 1), and its function is unknown. The remainder (< 20%) is bound to transcobalamin II (TCII) and it is this fraction that is biologically active (available for delivery to cells). Vitamin B12 bound to TC11 is called holotranscobalamin.
Decreased B12 level:
dietary (vegetarians); pernicious anemia; gastrectomy; atrophic gastritis; small bowel disease or resection; bacterial overgrowth); pregnancy (especially last trimester).
Raised B12 level:
vitamin therapy; myeloproliferative disorders and leukaemias; liver disease; hypereosinophilic syndrome
Other tests for vitamin B12 deficiency
- Plasma methylmalonic acid (MMA)
- Holotranscobalamin
Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours : contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402
Dr Cam Kyle: CampbellK@adhb.govt.nz ext 22052
Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427
Dr Campbell Heron: CHeron@adhb.govt.nz ext. 23427