Active Vitamin B12 (Holotranscobalmin)

An Active Vitamin B12 (Holotranscobalamin) test measures the specific amount of vitamin B12 that is actually available for your body cells to use.

While a standard Vitamin B12 test measures all the B12 in your blood, a large portion of that is bound to a protein that keeps it inactive. This test zeroes in on the active fraction, making it a highly accurate and sensitive tool for detecting early vitamin B12 deficiency.