Holotranscobalamin (Active B12)

Test investigation

Holotranscobalamin (Active B12)

Laboratory offering test

NNUH, QEH, JPUH

Units

pmol/L

Also known as/Frequency of test

HoloTC

Comments precautions

Note: holotranscobalamin cannot be requested as a stand-alone test. Total Vitamin B12 levels < 300 ng/L are reflex tested for holotranscobalamin (HoloTC). HoloTC has greater diagnostic accuracy for B12 deficiency. Levels should always be interpreted in conjunction with haematological and clinical findings. Neurological features of Vitamin B12 deficiency can occur without anaemia

Sample type

Serum

Turnaround times (TAT) Urgent/Routine/GP or OPD

Within 4 hours/8 hours

Reference intervals

Holotranscobalamin level < 35 pmol/L is strongly associated with vitamin B12 deficiency.