The active Vitamin B12 (holotranscobalamin) blood test measures the level of the biologically active form of vitamin B12 in your blood. Vitamin B12 is crucial for nerve function, red blood cell production, and DNA synthesis. The active form is bound to a protein called transcobalamin and is the form that is readily available for the body’s cells to use.

Overview of the Active Vitamin B12 Blood Test

What is Active Vitamin B12?

  • Active Vitamin B12 (Holotranscobalamin): The portion of total vitamin B12 that is bound to transcobalamin, making it readily available for cellular uptake and utilization.
  • Importance: Essential for neurological function, red blood cell formation, and DNA synthesis.

Why is the Active Vitamin B12 Test Done?

The active Vitamin B12 test is performed to:

  • Diagnose Deficiency: Identify vitamin B12 deficiency, which can lead to anemia, neurological issues, and other health problems.
  • Monitor Treatment: Evaluate the effectiveness of vitamin B12 supplementation or treatment for conditions causing deficiency.
  • Investigate Symptoms: Investigate symptoms such as fatigue, weakness, memory issues, and neuropathy that may be related to vitamin B12 deficiency.

Test Procedure

  • Preparation: Typically, no special preparation is needed for the active vitamin B12 test. However, it is essential to inform your healthcare provider of any medications or supplements you are taking, as these can affect the results.
  • Blood Sample: A blood sample is drawn from a vein in your arm.
  • Laboratory Analysis: The sample is analysed in a laboratory to measure the level of active vitamin B12.

Factors Affecting Active Vitamin B12 Levels

Several factors can influence active vitamin B12 levels, including:

  • Diet: Vitamin B12 is primarily found in animal products. Vegans and vegetarians may be at higher risk of deficiency.
  • Absorption Issues: Conditions such as pernicious anemia, celiac disease, and Crohn’s disease can impair the absorption of vitamin B12.
  • Medications: Certain medications, such as proton pump inhibitors and metformin, can affect vitamin B12 absorption.
  • Age: Older adults are more prone to vitamin B12 deficiency due to decreased stomach acid production, which is necessary for B12 absorption.

Follow-Up and Next Steps

If your active vitamin B12 levels are low, your healthcare provider may recommend:

  • Dietary Changes: Increasing the intake of vitamin B12-rich foods such as meat, fish, dairy products, and fortified cereals.
  • Supplements: Taking oral vitamin B12 supplements or receiving vitamin B12 injections, especially in cases of severe deficiency or absorption issues.
  • Regular Monitoring: Periodic blood tests to monitor vitamin B12 levels and assess the effectiveness of treatment.
  • Addressing Underlying Conditions: Investigating and managing underlying health conditions that may be causing the deficiency.

Benefits and Risks

  • Benefits: Provides accurate assessment of biologically active vitamin B12 levels, which is crucial for diagnosing and managing deficiency. Helps guide treatment decisions and monitor effectiveness.
  • Risks: The test is low-risk, involving a simple blood draw. Some individuals may experience minor discomfort or bruising at the puncture site.

Conclusion

The active Vitamin B12 (holotranscobalamin) blood test is a valuable tool for assessing vitamin B12 status and diagnosing deficiencies. By measuring the biologically active form of vitamin B12, this test provides important information for managing health conditions related to vitamin B12 deficiency. Regular consultation with your healthcare provider is essential for interpreting test results and developing an effective plan to maintain adequate vitamin B12 levels and support overall health.

Results – 1 day from Laboratory receiving sample