Vitamin B12 (also known as cobalamin) is used to make new cells, and is required to keep your bone marrow, nerves and blood cells healthy. It is also important in maintaining memory.

Your body does not make vitamin B12, so you either absorb it from the food you eat or get it by taking supplements. Vitamin B12 is absorbed by attaching itself to a protein called intrinsic factor, which is produced by the cells that line the stomach.

Some of the benefits of vitamin B12 are that it:

• helps to produce healthy red blood cells
• keeps your nervous system healthy
• releases energy from food for your body (there is no evidence it affects weight gain or weight loss)
• helps to create RNA and DNA which are the building blocks of all cells in the body
• helps to maintain healthy skin, nails and hair
• helps prevent you from getting anaemia and developing symptoms like tiredness and weakness

According to the NHS, adults aged 19 to 64 years need about 1.5 micrograms of vitamin B12 a day. The recommended vitamin B12 levels may be different for children, pregnant women and older adults. Your levels are considered low if they are less than 200 nanograms/L in a blood test.

Some examples of foods that are high in vitamin B12 are:

• meat, especially beef, chicken and animal liver
• fish and shellfish, especially tuna, sardines and clams
• dairy, such as milk, cheese and yoghurt
• eggs
• breakfast cereal fortified with vitamin B12

Vitamin B12 is not naturally found in fruit, vegetables and grains. If you’re on a vegan diet and do not eat animal or dairy products you may be at risk of vitamin B12 deficiency, and are advised to take supplements as directed by your doctor.

If you do not get enough vitamin B12, this can affect your ability to make new and healthy cells and you may experience a low red blood cell count, which is known as anaemia. This can lead to symptoms such as tiredness and shortness of breath.

What causes vitamin B12 deficiency?

Vitamin B12 deficiency can be caused by any of the following:

• Pernicious anaemia is a condition of the immune system. Your body develops antibodies against the intrinsic-factor proteins produced by the cells in your stomach which help to absorb B12. These antibodies destroy the intrinsic factor proteins, making B12 absorption impossible. This results in low vitamin B12 or deficiency and causes abnormally large red blood cells to be produced, which cannot carry oxygen around your body effectively
• Diet If your diet is lacking in red meat, Fish, meat, eggs, milk, and other dairy or breakfast cereals which also contain vitamin B12, you may develop vitamin B12 deficiency over time. So if you are a vegan you may be more likely to become vitamin B12 deficient
• Medicines Certain medications can reduce the way that vitamin B12 is absorbed by your body, or make vitamin B12 deficiency worse. For example, metformin for treating diabetes, antipsychotic drugs, hormonal replacement therapy (HRT), oral contraceptives, and drugs for treating acid reflux like PPIs (proton pump inhibitors)
• Pregnancy B12 is transferred to the growing baby throughout pregnancy reducing the amount available to the mother.
• Surgery Stomach surgery such as a gastrectomy which involves removing part of your stomach may increase your risk of developing vitamin B12 deficiency due to reduced absorption
• Crohn's disease This disease can lead to inflammation of the digestive tract and may reduce how much vitamin B12 your body absorbs

What are the symptoms of vitamin B12 deficiency?

The symptoms are:

• tiredness
• weakness
• constipation
• loss of appetite
• weight loss
• megaloblastic anemia
• Nerve problems, such as numbness and tingling in the hands and feet
• problems with balance
• depression
• confusion
• dementia
• poor memory
• soreness of the mouth or tongue

At Superdrug Online Doctor, we offer 2 types of vitamin B12 testing services.

Basic vitamin B12 blood sample collection pack

This test checks for vitamin B12 as an indicator to see if your levels are abnormal. We will not be able to prescribe treatment for vitamin B12 deficiency just with the results of this test alone. You can order the basic vitamin B12 test from us by taking the following steps:

• Place an order and get your test delivered to your door (delivery is free)
• Collect your blood sample by following the instructions in the test kit
• Send your samples to our UK-based, accredited partner laboratory (postage is free)
• Once your results are available which usually takes 2 to 3 days, our doctors will review them
• One of our doctors will contact you through a secure and confidential message in your patient account, to let you know your results and give you advice and support on what to do next
• Sometimes the doctor may need to contact you to get more information, so please make sure your contact details are up to date on your patient account.

If you’ve already been diagnosed with vitamin B12 deficiency and have been receiving treatment elsewhere, we may be able to offer you a continuation treatment service. To do this, we will provide you with a form to give to your GP to fill in. Once it’s completed, we will be able to prescribe continuation treatment.

Extended vitamin B12 blood sample collection pack (B12, folate and intrinsic-factor antibodies)

This test is more comprehensive and checks for your vitamin B12 levels, folate levels and for any evidence of antibodies against intrinsic-factor proteins in your blood, which may prevent your body from absorbing vitamin B12 effectively.

The extended testing service is slightly more expensive than the basic testing, but with this test may allow you to start treatment with us if your results are abnormal.

To order the extended vitamin B12 test from us, fill in a short questionnaire and take the following steps:

• Place an order and get your test delivered to your door (delivery is free)
• Collect your blood sample by following the instructions in the test kit
• Send your samples to our UK-based, accredited partner laboratory (postage is free)
• Your results should be available in 2 to 3 days
• When we receive your results, our doctors will review them; we will contact you through your account and give you specific information on what to do next
• If your vitamin B12 levels come back low, depending on your other results and the answers you give about yourself, we may be able to offer you injectable vitamin B12 treatment at Superdrug Health Clinic. If this is the case, our doctors will send you a message advising you how to organise this

If you’re currently receiving treatment for vitamin B12 deficiency you request a treatment appointment through Superdrug Health Clinic, but will need to provide evidence from your doctor. You can organise this by contacting Superdrug Health Clinic on 0203 808 0064. You will be provided with a note to give to your GP, which they will complete and return to us.

If you’ve not had vitamin B12 treatment before, but feel you may be deficient and need treatment, you can receive this from Superdrug if you take an extended test which shows you are deficient.

The basic test kit only checks to see if the active level of vitamin B12 in your blood is abnormally low. An abnormal result from the basic test kit, is not enough to start treatment with us.

We recommend taking this test if you’re already getting treatment for vitamin B12 deficiency and need to check that your levels are within the normal range.

The extended test kit checks your vitamin B12 and folate levels, and for antibodies against intrinsic-factor proteins in your blood. If these antibodies are present this may prevent your body from absorbing vitamin B12, causing a condition known as pernicious anaemia.

If you take the extended test kit, and your B12 levels are low, you may be able to start injectable vitamin B12 treatment with Superdrug Health Clinic. One of our doctors will contact you for more information and advise you about the next steps.

How long does it take to recover from vitamin B12 deficiency?

The symptoms of vitamin B12 deficiency usually improve soon after you start treatment, but may take up to 6 weeks to improve. You may be advised to initially take vitamin B12 as often as every other day, until your symptoms improve.

After this time, depending on the cause of your vitamin B12 deficiency, you may need to take it continuously for life (if you have pernicious anaemia or are on a vegan diet), or just for a few months until your vitamin B12 levels return to normal.

Folate is also known as vitamin B9, and is another important vitamin needed by your body to make new cells every day. The man-made form of folate is called folic acid. As your body does not make folate, it needs to be absorbed from food or supplements.

Some examples of foods naturally high in folate are:

• leafy green vegetables, like spinach, kale and cabbage
• legumes, like chickpeas, beans and lentils
• nuts and seeds, like walnuts, almonds and sunflower seeds
• citrus fruits, like oranges, lemons and limes
• grains fortified with extra folic acid which can be found in some bread, pasta and cereals

What happens if I have low folate levels?

If your diet is low in folate, you may have folate deficiency which can lead to anaemia, if left untreated. Anaemia is a condition where your body produces fewer red blood cells than normal or, in some cases, abnormal red blood cells, which cannot carry oxygen properly around your body. This can lead to symptoms like tiredness, weakness, low mood, pins and needles and breathlessness.

Folate deficiency is treated with folic acid supplements, as advised by your doctor.

Intrinsic-factor protein is produced by the cells that line the stomach. Vitamin B12 needs to attach to this protein to be absorbed into the body.

What happens if I have antibodies against intrinsic-factor protein?

You may develop a condition where your body’s immune system produces antibodies that attack and destroy intrinsic-factor proteins. This condition is known as pernicious anaemia, and means that vitamin B12 cannot be absorbed properly.

If you have pernicious anaemia, even if you eat large amounts of foods rich in vitamin B12, your levels will still be low. You will need life-long treatment with vitamin B12 injections to improve your vitamin B12 levels.