Holo-TC (Holo-Transcobalamin)

Holo-Transcobalamin (Holo-TC) is the biologically active form of vitamin B12 that is bound to the transport protein Transcobalamin. The laboratory value measures the concentration of Holo-TC in the blood and provides early indications of a functional vitamin B12 deficiency.

A Holo-TC test is recommended for: People with non-specific symptoms such as fatigue, memory disorders or neurological complaints Patients with a normal or borderline vitamin B12 level, in whom a deficiency is suspected Persons with risk factors for vitamin B12 deficiency (e.g. vegans, elderly people) Patients with suspected pernicious anemia or malabsorption disorders

The test serves for the early detection of a vitamin B12 deficiency, before severe symptoms develop. It complements the classic vitamin B12 measurement and is particularly helpful in diagnosing functional deficiencies.

A low holo-TC value indicates a functional vitamin B12 deficiency, which can occur despite a normal serum B12 value. Symptoms are: Fatigue and concentration problems Tingling or numbness in the extremities Anemia or neurological disorders A normal value usually excludes a deficiency and makes further tests unnecessary.

The test is meaningful in case of non-specific complaints or in risk groups such as vegans and elderly people. Testing is also appropriate in case of suspected malabsorption or before starting supplementation.

Here is the translation: Holo-TC is a more sensitive marker than total cobalamin, as it only measures the biologically active form of vitamin B12. Alcohol abuse and medications can affect the Holo-TC level.