Vitamin B12, active Holo Transcobalamin Serum

Vitamin B12 Active Holo Transcobalamin (HoloTC) test is a blood test that measures the level of vitamin B12 that is bound to a protein called transcobalamin II (TCII), also known as HoloTC. This test is used to evaluate the functional, active form of vitamin B12.

Vitamin B12 is essential for the normal formation of red blood cells, and for the normal functioning of the nervous system. Deficiencies in vitamin B12 can lead to anemia and neurological symptoms, such as numbness and tingling in the hands and feet, balance problems, and memory loss.

The vitamin B12 level in the blood can be normal even in the presence of deficiency because the test measures the total vitamin B12, which includes both the active and inactive forms. The Active Holo TC test is a more specific test that can detect functional deficiency of vitamin B12, even if the total vitamin B12 level is normal.

This test is typically ordered if a healthcare provider suspects a deficiency of vitamin B12, or if the patient has symptoms of deficiency, such as anemia or neurological symptoms. It is also ordered if the patient has a condition or is taking medication that affects the absorption or metabolism of vitamin B12.

Associated Tests:

Vitamin B Complex Profile

Vitamin Profile

Vitamin B12 Test

Methylmalonic acids Quantitative Serum 

Written by : Supriya Kulkarni, Lead-Content & Training