This test measures total vitamin B12 in the blood. Low B12 can cause tiredness, pins and needles, memory problems and a particular type of anaemia. People who eat little or no animal produce, take metformin or acid-suppressing medicines, or have pernicious anaemia or gut conditions are most at risk. The test costs £75 plus the £50 phlebotomy fee, and results are usually available in 1 day.
No fasting is needed. If you have recently had B12 injections or high-dose supplements, tell the clinic, because the result will reflect them.
Tiredness, breathlessness, pins and needles, a sore tongue, mood changes and memory problems are typical, but many people have no symptoms at first.
Vegans and vegetarians, people over 60, people on metformin or long-term acid suppressants, and anyone with pernicious anaemia, coeliac disease or previous gut surgery.
No. There is no fasting or special preparation for this test.
Often yes. B12 and folate deficiency cause the same type of anaemia, so they are commonly tested together with a full blood count.