Diagnostics·Diagnostics
B12 blood test
Informed by recognized medical guidance
Overview
A B12 blood test checks the amount of vitamin B12 in your blood. Vitamin B12 is important for making red blood cells and keeping your nerves healthy. The test helps find out if you have a shortage of this vitamin, which can cause tiredness, weakness, or nerve problems.
Key facts
- Vitamin B12 is mainly found in meat, fish, eggs, and dairy products.
- The test is a simple blood sample taken from your arm.
- Low B12 levels can be treated with supplements or injections.
B12 deficiency is fairly common, especially in older adults, people with certain digestive conditions, and those on a strict vegan diet.
It can affect anyone, but is more common in older adults, vegetarians, vegans, people with stomach or intestinal conditions (like Crohn's or celiac disease), and those who have had stomach surgery.