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Vitamin B12 Test

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If you’re feeling tired and weak a vitamin B12 test might explain why. Low levels cause fatigue, and a home B12 test will give you a quick and accurate measurement.
What's included
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We recommend testing your Ferritin and full blood count with this B12 test kit. You can add these extra biomarkers from as little as £5 to help monitor your health more accurately. Vitamin B12 and iron are needed to make red blood cells. Ferritin levels indicate how much iron is available.

Dr Nicky Keay - Forth
“Vitamin B12, alongside ferritin (also known as haematinics) are required to make red blood cells. I would therefore recommend adding ferritin and FBC to this test which will give you a fuller picture of your health rather than a single haematinic.”

Dr Nicky Keay
Chief Medical Officer & endocrinology expert

Why Check Vitamin B12 levels?

Vitamin B12 alongside folate is vital for the formation of red blood cells and its also important for nerve health.

Because red blood cells contain the protein haemoglobin, whose primary role is to transport oxygen around the body, low vitamin B12 levels can result in fewer red blood cells or a low amount of haemoglobin. Reduced levels of B12 can therefore lead to fatigue, lethargy, and feelings of weakness.

What is
Active B12?

Our vitamin B12 blood test measures active B12 rather than total B12 and is the most accurate way of measuring your available level of vitamin B12. An active B12 test is the best early indicator of possible deficiency because it measures the total amount of B12 available for your body to use. The human body can store enough vitamin B12 to last a few years but certain groups are at a greater risk of deficiency because their stores will be depleted or they may have issues absorbing it from their diet.

Prolonged vitamin B12 deficiency can lead to anaemia, so spotting it early can help prevent this.

Vitamin B12 deficiency
1 in 10 people
in the UK are believed to be deficient in vitamin B12 (Pernicous Anemia Society).
Optimal levels
50% of customers
improved their B12 result between tests.

Who are most at risk of vitamin B12 deficiency?

Vitamin B12 is mostly found in meat as well as chicken and fish so vegans and vegetarians are at a greater risk of vitamin deficiencies including B12. Therefore, a vegan or vegetarian diet must be planned appropriately, which may mean eating fortified foods 2-3 times per day or by taking a vitamin B12 supplement.

Older people are also at an increased risk of vitamin B12 deficiency and a folate deficiency, possibly due to poor dietary intake. 

Dr Nicky Keay
the Experts Opinion

Vitamin B12 is one of the nutrients required to make red blood cells. Low levels can lead to a decrease in red blood cell production and potentially anaemia and also an increase in red blood cell size. Vitamin B12 is also important for neurological function. Testing blood levels of vitamin B12 can help detect low levels that need addressing whether through diet or supplementation if a vegetarian or vegan.

Dr Nicola Keay
Forth Chief Medical Officer

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Frequently asked questions

 Here are some of the most frequently asked questions. If you need anything else try our help section.

  • What is active B12?

    Active B12 is the total amount of vitamin B12 available for use within your body. It is essential for the development of red blood cells as well as DNA. It also has important roles in nerve function.

  • What is the normal level of B12?

    The vitamin B12 test will show if your active vitamin B12 levels are above the minimum normal range of 37.5 pmol/L.

  • What are the symptoms of low Vitamin B12

    Low vitamin B12 levels can cause:

    • Fatigue
    • Sore tongue
    • Mouth ulcers
    • Blurred vision
    • Pins and needles
    • Irritability
    • Depression
    • Problems remembering things
    • Changes in the way you walk or move
    • Pale yellow tinge to the skin
  • Do I need to take vitamin B12 supplements?

    If you eat a healthy, balanced diet you should acquire all the vitamins and minerals your body needs to function properly. However, someone who is on a vegan or vegetarian diet might need to take a vitamin B12 supplement, particularly because most of the vitamin comes from animal-based sources. There are some vitamin B12 fortified sources but these may be limited.

  • How to check B12 levels?

    You can check vitamin B12 levels using our at-home vitamin B12 test kit. Our test enables you to check your active B12 levels quickly, easily, and affordably. Simply send your sample direct to our UKAS accredited lab and your accurate result will be available within 48hrs on our secure digital dashboard.

  • What’s the difference between total and active B12?

    Active B12 is best way to test B12 as it only measures the form of vitamin B12 that is available to be used by the body. A total B12 test, which is the standard test offered by the NHS, measures the total amount of both active and inactive B12.

    The problem with testing for total B12 is that the test may show as normal but mask low levels of active B12. Active B12 typically makes up around 10% to 30% of B12 in the body.

    Read more in our blog.

  • What does high B12 mean?

    Generally, high levels of vitamin B12 are not considered to be toxic which is why there isn’t an upper range. Very high levels are rare but are seen in some types of leukaemia or liver disease.

  • How can I increase my Vitamin B12 levels?

    The human body doesn’t make vitamin B12 which makes it an essential vitamin. That means it must be absorbed through the diet or by taking a supplement.

    So, the best way to naturally increase your vitamin B12 levels is to eat a wide variety of foods and be sure to incorporate some rich B12 sources.

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