Diagnostics·Diagnostics
Preparing for B12
Informed by recognized medical guidance
Overview
Vitamin B12 deficiency means you don't have enough vitamin B12 in your body. B12 helps make red blood cells and keeps your nerves healthy. A blood test can check your B12 level. Preparing for the test usually means telling your doctor about any supplements you take – they may ask you to stop taking them a few days before.
Key facts
- B12 deficiency can cause anemia (low red blood cells) and nerve damage.
- It is easy to treat with B12 replacement, often as injections or tablets.
- You can help prepare for a B12 test by not taking B12 supplements for a few days before, unless your doctor says otherwise.
Yes, B12 deficiency is common, especially in older adults and people with certain health conditions.
It most often affects people with pernicious anemia (an autoimmune condition), those who follow a strict vegan or vegetarian diet, people who have had stomach surgery, older adults, and people taking long-term acid-reducing medicines.