Advanced Vitamin B12 Blood Test, from our experts to you.
Dr Sam Rodgers MBBS, MRCGP

Chief Medical Officer meet our doctors

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What can I learn
from this test?

Our Advanced Vitamin B12 Blood Test thoroughly investigates vitamin B12 deficiency. It examines the levels of active vitamin B12, folate (vitamin B9) and ferritin (iron status) in your blood and includes a full blood count (FBC) to identify whether a lack of B12 is affecting the size of the red blood cells (which affects their oxygen-carrying capacity). Folate and ferritin are helpful to test as deficiencies in these nutrients can cause similar symptoms as a vitamin B12 deficiency.


What is
vitamin B12?

Vitamin B12 is an essential water-soluble vitamin found in virtually all meat products and certain algae, such as seaweed. It helps maintain healthy nerve and red blood cells and is also needed to make DNA, the genetic material in all cells.


What happens if
vitamin B12 is low?

Vitamin B12 deficiency symptoms usually develop gradually but can worsen if the condition goes untreated. Symptoms include headaches, feeling faint, pale skin, and palpitations. Pernicious anaemia prevents B12 absorption by stopping the production of intrinsic factors and is the leading cause of vitamin B12 deficiency. You may be at risk of a deficiency if you have pernicious anaemia, are vegetarian or vegan or have recently had gastric bypass surgery.


What's included?

Clotting status
Iron status
Red blood cells
Vitamins
White blood cells
Select profile for more information

Platelet count Platelets or clotting cells are the smallest type of blood cell. They are formed in the bone marrow and are important in blood clotting. When bleeding occurs, the platelets swell, clump together and form a sticky plug (a clot) which helps stop the bleeding.
MPV MPV, or Mean Platelet Volume, is a measurement of the average size of your platelets. Platelets are fragmented cells within the blood that aid the process of clot formation. MPV provides an indication of platelet production in your bone marrow.
Ferritin Ferritin is a protein which stores iron in your cells and tissues. Usually, the body incorporates iron into haemoglobin to be transported around the body, but when it has a surplus, it stores the remaining iron in ferritin for later use. Measuring ferritin levels gives us a good indication of the amount of iron stored in your body.
Haemoglobin Haemoglobin is a protein in red blood cells which carries oxygen around the body and gives the blood its red colour. This test measures the amount of haemoglobin in the blood and is a good measure of the blood's ability to carry oxygen around the body.
Haematocrit HCT (haematocrit) measures the amount of space (volume) within the blood that is taken up by red blood cells.
Red cell count Red Blood Cell (RBC) Count analyses the number of red blood cells in the blood. Red blood cells carry oxygen from the lungs to the rest of the body, where it can be used to fuel energy processes such as movement and respiration. They also carry carbon dioxide produced from cells back to the lungs so that it can be exhaled.
MCV MCV (mean corpuscular volume) reflects the average size of your red blood cells. This is important to measure, as it can indicate how much oxygen your cells are likely to be transporting around the body.
MCH MCH (mean corpuscular haemoglobin) measures the average amount of haemoglobin contained in one of your red blood cells.
MCHC MCHC (mean corpuscular haemoglobin concentration) is the average concentration of haemoglobin in your red blood cells. Haemoglobin is a molecule which allows red blood cells to transport oxygen around the body.
RDW Red blood cell distribution width (RDW) indicates whether your red blood cells are all the same size, or different sizes or shapes. Normally cells are fairly uniform both in size and in shape, but some blood disorders may cause your red blood cells to form in abnormal sizes. This test measures the difference between the largest and the smallest red blood cell.
Folate - serum Folate is a B vitamin which acts as a coenzyme in the metabolism of amino acids. It is also vital for the synthesis of purines and pyrimidines which are essential for DNA synthesis and red cell formation. Folate is also especially important during the first trimester of pregnancy so if you are thinking of becoming pregnant it is important to make sure your folate levels are normal.
Vitamin B12 - active Vitamin B12 is important for production of red blood cells which carry oxygen around the body. B12 is also involved in metabolism and the nervous system and prolonged lack of vitamin B12 may cause nerve damage. Although Vitamin B12 is almost entirely found in animal-based foods, many vegetarian and vegan products, especially plant milks are now fortified with Vitamin B12.
White cell count White Blood Cell (WBC) Count measures the number of white blood cells in the blood. White blood cells are key to your body's immune system. They fight infections and protect your body from foreign invaders such as harmful germs and bacteria. Additionally, they produce many antibodies and memory cells to protect you from further infections with the same germ.
Neutrophils Neutrophils are the most abundant type of white blood cell in the body and are responsible for helping your body fight infection. When a germ is initially detected by the body, neutrophils are the defence system which go out and attack the germ before any of your other white blood cells. When neutrophils are low you can be more vulnerable to illness and infection.
Lymphocytes Lymphocytes are a type of white blood cell which fight bacterial and viral infections. They are the subset of white blood cells involved in the more specific response to infections, which can identify and differentiate between different foreign organisms that enter the body. As well as fighting infection, they produce antibodies and memory cells to help to prevent future infections from the same germ. Lymphocytes include T cells, B cells and natural killer cells.
Monocytes Monocytes are a type of white blood cell that surround and destroy germs and dead or damaged cells from the blood. The heat and swelling that you feel when a body part is inflamed, for example after a cut on your finger, is caused by the activities of these cells.
Eosinophils Eosinophils are a type of white blood cell that are responsible for removing parasitic infections and regulating inflammation to mark an infected site. They also play a role in allergy and in asthma.
Basophils Basophils are a type of white blood cell that protect your body from bacteria and parasites such as ticks. They also play a role in allergic reactions.

How to prepare
for your test

Special instructions

Prepare for your Advanced Vitamin B12 Blood Test by following these instructions. You should take this test before you take any medication or vitamin/mineral supplements. Do not take biotin supplements for two days before this test, discuss this with your doctor if it is prescribed. Do not take vitamin B12 for two weeks prior to this test. If your B12 is prescribed ask your doctor whether to stop.


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