Vitamin B12 Blood Test Kit (UK) | Energy & Vitality Check
Biomarkers
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Viatmin B12
Vitamin B12, also known as cobalamin, is an essential nutrient the body cannot produce on its own and must obtain through diet or supplementation. It plays a fundamental role in the formation of red blood cells, DNA synthesis, neurological function, and the maintenance of healthy nerve tissue. It is found naturally in animal products including meat, fish, eggs, and dairy, which is why deficiency is particularly common in those following a plant-based diet. Low B12 can have a wide-ranging impact on both physical and neurological health, making regular monitoring important for those at risk.
Frequently Asked Questions
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What does a vitamin B12 blood test measure?
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It measures the amount of vitamin B12 circulating in your blood, giving a quantitative reading that helps identify whether your levels are within a healthy range, deficient, or borderline low. The report includes actual figures and flags any results that fall outside the normal range.
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Who is at risk of vitamin B12 deficiency?
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Those most at risk include vegans and vegetarians, as B12 is found almost exclusively in animal products; older adults, as absorption declines with age; people with gastrointestinal conditions such as pernicious anaemia, coeliac disease, or Crohn's disease; and those who have undergone gastrointestinal surgery. People taking certain long-term medications such as metformin or proton pump inhibitors are also at increased risk.
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Can vitamin B12 deficiency cause anaemia?
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Yes. B12 deficiency can lead to megaloblastic anaemia, a condition where the body produces abnormally large red blood cells that do not function properly. A B12 blood test can help identify whether anaemia is linked to a B12 deficiency or another underlying cause.
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How often should I test my vitamin B12?
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If you are symptomatic, at risk, or currently being treated for deficiency, testing every 3 to 6 months is a reasonable guide. For those monitoring general health or following a plant-based diet, an annual test is a sensible baseline. Your GP can advise on the most appropriate frequency based on your individual circumstances.
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Is this test measuring active or total vitamin B12?
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This test measures total vitamin B12, which includes both active and inactive forms circulating in the bloodstream. Active B12 is the smaller fraction the body can actually use, and it is possible to have a normal total B12 result while active levels are low. If symptoms persist despite a normal result, testing active B12 separately may provide a clearer picture.
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Do I need to stop taking B12 supplements before the test?
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If you are taking prescribed vitamin B12 supplements, please check with your prescriber before testing, as they may advise stopping them at least 72 hours befo…If you are taking prescribed vitamin B12 supplements, please check with your prescriber before testing, as they may advise stopping them at least 72 hours before collecting your sample. Recent intake can temporarily elevate levels and may not accurately reflect your true B12 status.
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Turnaround Time
Turnaround Time
Test Preparation
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Vitamin B12
Fasting: While strict fasting is not required, you must avoid a high-fat meal for at least 6 hours before taking your blood sample. Fatty meals can cause lipemia, a condition where the blood looks cloudy or milky, which may affect the accuracy of your results.
Supplements: If you are taking prescribed vitamin B12 supplements, please check with your prescriber before testing, as they may advise stopping them 24 to 72 hours before collecting your sample. Recent intake can temporarily elevate levels and may not accurately reflect your true B12 status.
Hydration: Drink water as normal before testing, as good hydration can make blood collection easier.
Symptom Check
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Low vitamin B12
Common symptoms include persistent fatigue, weakness, brain fog, poor concentration, low mood, numbness or tingling in the hands and feet, and in more advanced cases neurological changes and anaemia. Because symptoms develop gradually and overlap with many other conditions, deficiency is often missed without testing.
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High vitamin B12
Elevated B12 levels are most commonly caused by supplements or injections and are generally not a cause for concern in these situations. Stopping supplementation before repeat testing can help confirm whether this is the cause.
Where levels are significantly elevated without supplementation, further medical evaluation may be recommended, as high B12 can occasionally be associated with liver disease, kidney disease, certain blood disorders, or chronic inflammation.
Symptoms that can be associated with elevated B12 include acne or facial redness, anxiety, headaches, heart palpitations, insomnia, nausea, high blood pressure, and in some cases discoloured urine. Any symptoms are more likely to be related to an underlying condition than to the elevated B12 itself, and should be discussed with a GP if persistent.
Result Report
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Result Report (in-use)
The final report provides a comprehensive breakdown of your biomarkers, displaying your specific levels alongside standard UK reference ranges to show exactly where you fall on the spectrum. Beyond just the raw numbers, the report includes a brief commentary.
View your results in a clear, easy-to-understand format with charts and reference ranges. If you repeat the same biomarkers with us, your report includes historical comparisons to help track changes, trends, and progress over time.
Vitamin B12 is an essential nutrient that your body relies on to function properly, yet it cannot produce it on its own. It plays an indispensable role in red blood cell formation, neurological function, DNA synthesis, and cellular energy production. When your B12 levels run low, it can show up in your day-to-day life as unrelenting fatigue, constant muscle weakness, annoying pins and needles, mood swings, and frustrating brain fog.
Our At-Home Vitamin B12 Blood Test Kit is a clinical-grade check designed to measure your exact levels of active B12 circulating in your blood. Unlike generic diet diaries or symptom tracking, this simple blood test gives you an undeniable biological snapshot of your internal health. It is an absolutely vital check for vegans, vegetarians, and plant-based eaters, as Vitamin B12 is almost exclusively found in animal-derived foods. It is also highly recommended for older adults or anyone taking long-term acid reflux medications, which can drastically inhibit dietary B12 absorption.
How to test your B12 levels from home: There is no need to book a clinic slot or wait for a standard doctor's appointment. Our kit includes everything required to complete the test completely from the comfort of your living room.
Simply perform a quick, minimally invasive finger-prick using the provided sterile lancet to collect a small blood sample into the collection tube. Once done, place your sample into the prepaid return envelope and drop it into any priority postbox.
Your sample is routed directly to our CQC-regulated UK laboratory for expert analysis, guaranteeing hospital-grade accuracy and strict data privacy. Within 1 to 3 working days of laboratory receipt, your final quantitative results will be securely delivered to your private digital dashboard, complete with clear visual reference ranges and professional doctor-reviewed commentary.
How it works
Order test online
Collect a few drops at home
Return sample to the lab
