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Active B12

What Is the Active B12 Test?

The Active B12 test measures the concentration of biologically active vitamin B12, known as holotranscobalamin, in the blood. This is the form of B12 that is immediately available for use by the body, particularly for energy production and maintaining nervous system health.

How Active B12 Differs from Standard B12 Testing

Unlike standard B12 tests that measure total B12—including both active and inactive forms—the Active B12 test specifically quantifies the amount that is bioavailable to the body’s cells. This allows for a more accurate assessment of your functional B12 status.

Why Active B12 Testing Matters

Active B12 plays a vital role in DNA synthesis, red blood cell production, and proper nerve function. Deficiency in this essential vitamin can lead to symptoms such as fatigue, anaemia, cognitive issues, and nerve damage. Early detection through this test can lead to timely treatment, even in cases where total B12 levels appear normal.

When Should You Consider the Active B12 Test?

This test may be recommended if you experience:

Ongoing fatigue or weakness

Numbness, tingling, or memory problems

Risk factors for poor absorption, such as gastrointestinal disorders, increasing age, or a vegan/vegetarian diet

The need to monitor B12 supplementation or treatment effectiveness

What Can the Active B12 Test Detect?

The Active B12 test helps identify true vitamin B12 deficiency and conditions affecting nutrient absorption, such as pernicious anaemia or other digestive system disorders. It also distinguishes between real deficiencies and cases where total B12 readings are misleadingly normal.

Do You Need to Fast for the Test?

Fasting is not required for the Active B12 test unless your healthcare provider advises otherwise.

Private Active B12 Testing in Slough and Nearby Areas

We offer private Active B12 blood testing at our clinic in Slough for early and accurate detection of B12 deficiency. Our services are available to patients in Slough, Windsor, Maidenhead, Langley, and Burnham, with personalised follow-up care for maintaining optimal energy and neurological health.

There is an additional £20 phlebotomy fee for every donation.