The traditional method of diagnosing vitamin B12 deficiency has been to measure the concentration of total vitamin-B12 in the serum. The total vitamin B12 concentration essentially reflects vitamin-B12 which is bound to its two carrier proteins forming, holohaptocorrin (holoHC) and holotranscobalamin(holoTC). Whilst holoHC accounts for 70 % – 80 % of the vitamin B12 in serum, only holoTC (active vitamin B12) can be used by human cells. Measurement of total vitamin B12 can hence give erroneous results because it measures the vitamin B12 which is in circulation but does not indicate the active vitamin B12 that is available to the cells of the body.
Biohit Active B12 test provides a solution to this diagnostic paradox: this test directly measures (holoTC) – the biochemically active form of vitamin B12 – from the human serum. This test is well suited for the screening of patients with a suspected vitamin B12 deficiency. Biohit Active B12 test can also be used for confirming the vitamin B12 status in the large number of patients who get an inconclusive result from total vitamin B12 tests.