Educational information only. At Precursor, blood testing is requested and reviewed by a clinician and considered alongside your history and other markers, not as a stand-alone diagnosis. Testing is performed in NATA-accredited laboratories to ISO 15189 standards.

What is vitamin B12?

Vitamin B12 is an essential nutrient needed to make red blood cells, maintain the nervous system, and support DNA production. Your body cannot make it, so it must come from food, mainly animal products, or supplements. It is stored in the liver, so deficiency can take time to appear.

Why it matters

B12 deficiency is important to catch because, left unaddressed, it can affect both blood and nerves. It is more common in people following plant-based diets, older adults, and those on certain medications, making it a valuable marker to check.

What your results can mean

Lower than optimal

A low B12 can cause a particular type of anaemia and, over time, nerve-related symptoms. It is usually straightforward to address once identified, which is why testing is worthwhile.

Within the healthy range

A B12 in range supports healthy blood and nerve function. Interpretation can be nuanced near the lower end, where additional markers sometimes help.

Reference ranges in Australia

Vitamin B12 is reported in picomoles per litre (pmol/L), with laboratory-specific reference ranges. Because borderline results can be tricky, read your result against your own report and with a clinician.

Test your vitamin B12 with Precursor

B12 is best read alongside folate and your blood count. At Precursor it is measured as part of Full Advanced Bloods, a single clinician-reviewed blood draw covering your vitamins, full blood count and other markers together, giving you and your clinician a broad baseline to understand and track.