The Vitamin B12 Binding Capacity, Unsaturated test contains 1 test with 1 biomarker.
Brief Description: The Unsaturated Vitamin B12 Binding Capacity (UVBC) test, also known as Transcobalamin I (TCI) or R-binder capacity test, measures the amount of available binding sites for Vitamin B12 on proteins in the blood. Transcobalamins are proteins that transport vitamin B12 through the bloodstream to cells. When these proteins are not bound to vitamin B12, they are termed "unsaturated."
Collection Method: Blood Draw
Specimen Type: Serum
Test Preparation: No preparation required
This test may be ordered when:
Vitamin B12 Deficiency is Suspected: Especially if the cause of the deficiency is uncertain.
Evaluating Pernicious Anemia: To determine the cause of B12 deficiency and differentiate between pernicious anemia and other types of B12 deficiency anemias.
Monitoring Treatment: For patients already known to have B12 deficiency or are undergoing treatment for pernicious anemia.
The UVBC test measures the capacity of proteins in the blood to bind with vitamin B12. A high UVBC means there is an excess of these proteins available to bind with B12, which can indicate a deficiency in the actual vitamin B12.
When assessing for vitamin B12 deficiency or its causes, the following tests might be ordered alongside the UVBC:
Serum Vitamin B12 Level: Directly measures the amount of vitamin B12 in the blood.
Methylmalonic Acid (MMA): Elevated levels can be an early indicator of vitamin B12 deficiency.
Homocysteine: Elevated levels can be seen in both vitamin B12 and folate deficiencies.
Intrinsic Factor Antibody: To help diagnose pernicious anemia.
The main conditions or diseases that might prompt a UVBC test include:
Vitamin B12 Deficiency Anemia: Where there's a reduced amount of red blood cells due to a lack of B12.
Pernicious Anemia: A specific type of B12 deficiency anemia where the body can't absorb enough B12 due to a lack of intrinsic factor, a protein made in the stomach.
Results from the UVBC test can guide healthcare providers in:
Differential Diagnosis: Differentiating between different causes of vitamin B12 deficiency anemias.
Guiding Treatment: Determining the appropriate treatment, especially if B12 supplementation is needed.
Monitoring: Tracking the effectiveness of treatment and ensuring that B12 levels return to and remain at a normal range.
In summary, the Unsaturated Vitamin B12 Binding Capacity test is a valuable diagnostic tool in assessing vitamin B12 status and understanding the potential causes of a deficiency. It assists healthcare providers in making informed decisions about patient care and treatment related to vitamin B12-related conditions.
Why is the Unsaturated Vitamin B12 Binding Capacity test ordered?
The Unsaturated Vitamin B12 Binding Capacity test is primarily ordered to evaluate the capacity of the blood to bind to vitamin B12. It helps to assess the amount of transcobalamin, the protein that carries vitamin B12 in the blood, which can provide insights into certain medical conditions and vitamin B12 metabolism.
How does the Unsaturated Vitamin B12 Binding Capacity test differ from a total Vitamin B12 test?
While the total Vitamin B12 test measures the concentration of vitamin B12 in the blood, the Unsaturated Vitamin B12 Binding Capacity test determines the capacity of proteins in the blood, specifically transcobalamin, to bind to additional vitamin B12. The latter helps to assess the body's ability to transport and utilize vitamin B12 effectively.
What do elevated levels in the Unsaturated Vitamin B12 Binding Capacity test suggest?
Elevated levels may suggest increased production of transcobalamin, which can be seen in conditions like chronic liver disease, certain types of leukemia, or polycythemia vera.
What do low levels in the Unsaturated Vitamin B12 Binding Capacity test indicate?
Low levels of unsaturated vitamin B12 binding capacity can indicate a deficiency in transcobalamin. This might result from congenital conditions or be acquired due to certain diseases, affecting the body's ability to transport vitamin B12 effectively.
How can the results of the Unsaturated Vitamin B12 Binding Capacity test influence treatment decisions?
If the test results indicate an abnormal binding capacity, it may guide healthcare professionals to further investigate the underlying cause and adjust the treatment accordingly. For instance, if there's reduced binding capacity due to a transcobalamin deficiency, vitamin B12 injections might be recommended to ensure adequate vitamin B12 levels in the body.
Can the Unsaturated Vitamin B12 Binding Capacity test be used to monitor the efficacy of vitamin B12 supplementation?
Not directly. The test primarily assesses the body's ability to bind and transport vitamin B12. While it can provide information on vitamin B12 metabolism, monitoring the efficacy of supplementation is typically done using the total Vitamin B12 test.
How does the Unsaturated Vitamin B12 Binding Capacity test relate to total binding capacity?
The Unsaturated Vitamin B12 Binding Capacity measures the amount of additional vitamin B12 that can be bound by the blood's proteins. In contrast, the total binding capacity measures both the bound and unbound capacity. The unsaturated capacity is the difference between the total capacity and the amount of vitamin B12 already bound.
Why might a doctor order both the Unsaturated Vitamin B12 Binding Capacity test and a total Vitamin B12 test?
Ordering both tests provides a comprehensive view of vitamin B12 status in the body. The total Vitamin B12 test gives a measure of the current vitamin B12 levels, while the Unsaturated Vitamin B12 Binding Capacity test offers insights into the body's ability to transport and utilize this essential vitamin. Together, they can help diagnose or rule out conditions related to vitamin B12 metabolism and transport.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.
The following is a list of what is included in the item above. Click the test(s) below to view what biomarkers are measured along with an explanation of what the biomarker is measuring.
Also known as: Vit B12 Binding Capacity Unsat Transcobalamin