Vitamin B12 plays an important role in the body and if you are feeling tired or weak it could be a sign your are deficient.  But a total B12 blood test gives an inaccurate picture of your B12 levels as it's active B12 that the body uses.

What Is Active B12? How Does It Differ From Total B12?

Vitamin B12 can take two forms in the body:

  • Active B12 (or ‘holotranscobalamin,’ as the medical professionals might call it!)
  • Inactive B12

The active form of B12 can be used by the body, where the inactive form cannot. In other words, it’s the levels of active B12 we really need to be concerned with if we are worried about thyroid issues, fatigue or any other symptoms associated with a B12 deficiency.

The Problem with Testing Total B12 Levels

The most widely used B12 test on the NHS is one that checks total levels of B12, including the inactive form of it.

This means that your B12 levels might show as normal following one of these blood tests, but that in reality you could have low levels of active B12 - the version the body can actually use. Active B12 typically makes up 10% - 30% of all the B12 in the body, so someone sitting in the “normal,” range with the widely used serum tests might actually be B12 deficient.

In other words, this sort of testing could fail to diagnose a deficiency accurately.

Why Test Your B12 Levels?

There are a number of reasons to check your Vitamin B12 levels including:

  • You’re concerned about a thyroid disorder
  • You are experiencing unexplained fatigue

However, while many people are familiar with B12 testing, many aren’t familiar with or are not aware of active B12 testing and the advantages it offers.

Want to find out your Active B12 level?

Active B12 tests are not commonly available through the NHS but you can gain insight into your active B12 levels quickly and easily with our home finger-prick test kit.  Simply collect a small sample of blood at home and post it direct to our accredited lab for analysis.  Your results will be available within 24-48 hrs on your own online personal health dashboard.