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Trusted to do 100,000+ tests and consultations per month.
Trusted to do 100,000+ tests and consultations per month.
Vitamin B12 (Active and Total) Blood Test

 


VITAMIN B12 (ACTIVE AND TOTAL) BLOOD TEST

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£69.00
£69.00 - £69.00
£69.00
£69.00 - £69.00
2 BIOMARKERS
3 DAYS
INSTRUCTIONS
FAQ

This test is used to diagnose vitamin B12 deficiency, which can lead to symptoms such as fatigue, weakness, neurological problems, and megaloblastic anemia.

Simple and accurate blood test from a laboratory you can speak to.



STEP 1 - CHOOSE YOUR SAMPLE COLLECTION OPTION
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VITAMIN B12 (ACTIVE AND TOTAL) BLOOD TEST OVERVIEW

Check and manage the level of vitamin B12, both active and total, in your body with this test.

Symptoms of low vitamin B12 are abundant, including tiredness, lack of energy, headaches and many others.

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VITAMIN B12 (ACTIVE AND TOTAL) BLOOD TEST

Check and manage the level of vitamin B12, both active and total, in your body with this test. Vitamin B12 is essential for most body systems, particularly in haematology with the manufacture of blood cells and hence healthy function of the organism as a whole, including the nervous system. Symptoms of low vitamin B12 are abundant, including tiredness, lack of energy, headaches and many others.

This test measures both active and total levels of Vitamin B12

Total B12 refers to the measurement of all forms of vitamin B12 present in the blood. This includes both active B12 (methylcobalamin and adenosylcobalamin) and inactive B12 forms (such as cyanocobalamin). The measurement of total B12 provides an overall picture of the total B12 content in the bloodstream, regardless of whether the B12 forms are actively available for body use.

Active B12, also known as cobalamin, refers to the biologically active forms of vitamin B12 that are immediately available for the body to use. The two primary active forms are methylcobalamin and adenosylcobalamin. These active forms play essential roles in various physiological processes, particularly in energy metabolism and nerve function. Active B12 is measured up to concentration of 150. 

Why it is important to measure both.

The distinction between total B12 and active B12 is crucial because not all forms of B12 are biologically active or readily usable by the body. Cyanocobalamin, for example, is an inactive form of B12 that requires conversion into active forms before the body can utilise it. Methylcobalamin and adenosylcobalamin are already in their active forms and can be directly utilized by cells.

In some cases, only total B12 levels are measured, which may not give a complete assessment of B12 status. It is often beneficial to measure active B12 levels (or other markers like free B12/holotranscobalamin) to better understand the body`s immediate access to functional B12.

This test measures both forms.

2 BIOMARKERS

  1. VITAMINS

    - Total Vitamin B12
    - Active Vitamin B12
    - Turnaround time for this test is up to 3 days for active B12.

  2. UPGRADE

    Need more biomarkers? Add these markers to our Ultimate Performance Blood Test


  1. TURNAROUND TIME

    We are extremely fast, with some results available within hours and others within a working day or less, from the time your sample is in our lab. However, this is not a guarantee and should not be taken as such. This is the guideline turnaround time that can be shorter or longer.


    THIS IS NOT A GUARANTEED TURNAROUND TIME.


    We are extremely proud of our very short turnaround times and a very efficient laboratory processes, you will start receiving results as soon as they are available and have completed clinical validation.


    Whilst we accommodate the shortest of time scales, with some results available within hours, for this particular test the usual turnaround time is: 3 working days.

  1. WILL I HAVE A GENERAL EXPLANATION OF MY RESULTS?

    Yes, our doctors put a huge amount of effort into your online Health Dashboard, which will have explanations of what each biomarker is, the normal reference ranges and what it means if you are outside of them.


    This service is included in the price of all our tests.

  1. CAN I SEE A GP TO DISCUSS MY RESULTS?

    Yes, usually the same or next day.


    One Day Tests has a fantastic clinical team of consultants and GPs. Once you have your results you can book an online video consultation to discuss your results.


    Our clinical team consists of practicing NHS and private GPs, who work closely with our laboratory and can tell you what your blood test results mean for you. Having an integrated laboratory and GP services makes your health journey seamless and extremely efficient.


    This service is not included in the price of the test, it is charged separately, should you wish to book it.

DOCTOR'S COMMENTS

Hi, I am Dr. Adam Staten and here's my view on this test as a GP and Clinical Director at One Day Tests.

DR. ADAM STATEN - GP VIEW AND RED FLAG SYMPTOMS

From a medical perspective, testing vitamin B12 levels is important because this vitamin supports the production of healthy red blood cells, maintains proper nerve function, and helps keep the brain working efficiently.

A deficiency can develop gradually and cause a range of symptoms, from fatigue and difficulty concentrating to numbness, tingling, or even mood changes, many of which can be mistaken for other conditions.

Certain groups, such as older adults, people with digestive issues, or those following vegetarian or vegan diets, are more likely to be deficient.

Early testing helps identify low levels before they lead to long-term problems, allowing for timely treatment through dietary changes or supplementation.

Red flag symptoms for the Vitamin B12 (Active and Total) Blood Test

Even if your blood tests are normal, see your doctor if you have any of the symptoms below.

  • Chest pain or shortness of breath on exertion
  • Unexplained abdominal swelling or fluid around the ankles or eyes
  • Unexplained weight loss

Your Results and Health Dashboard

The results of your Vitamin B12 (Active and Total) Blood Test will be emailed to you as a secured PDF file, ready for your GP and will also be uploaded to our Health Dashboard area of the website. It’s a unique and powerful tool, powered by our in-house clinical analysis research, to match your biomarkers across test panels and symptoms, as well as provide clinical commentary on all individual biomarkers you tested for.

The health dashboard will also provide "panel level" commentary - a birds eye view of the biomarkers that were tested. This feature allows you to view your test results and clinical commentary, and compare them to previous results, giving you a clear understanding of how your health is progressing.

By using the Health Dashboard, you can identify changes in your biomarkers and make necessary adjustments to your lifestyle. This added value is immense, as it empowers you to monitor your health and make informed decisions about your well-being.

It's free and is available with all of our tests.

SAVE ON CONTINUOUS MONITORING WITH OUR SUBSCRIPTION PLAN

The best way to look after your health is to do so regularly. This is easy to do with our continual monitoring plans which give you a discount on future blood tests. You choose the frequency and we'll do the rest.

When you purchase a subscription, we will deliver your home test kits or allow you to book appointments in line with your chosen frequency. You will be able to track your biomarkers over time in our powerful Health Dashboard, where results will be automatically updated for you. There is a minimum of 3 tests with any subscription, after which you can pause/restart/cancel at any time.

SPECIAL INSTRUCTIONS

Hi, I am Stefania Brown, I am the Laboratory Manager at One Day Tests and here are the lab's special requests for the Vitamin B12 (Active and Total) Blood Test.

SPECIAL INSTRUCTIONS

Whilst we cannot advise stopping any medication and recommend you contact the prescribing doctor that issued the medicine, here are some of the conditions that affect the levels of B12:

If you're taking vitamin B12 supplements (including multivitamins or B-complex formulas), your prescribing doctor may advise you to stop them 24–72 hours before the test. This helps avoid artificially elevated levels that could mask an underlying deficiency.

Certain medications, such as proton pump inhibitors, metformin, or anticonvulsants, can affect B12 levels.

Check with the prescribing doctor but do not stop prescription drugs unless advised by the prescribing professional.

Clinic appointment - how to prepare for the Vitamin B12 (Active and Total) Blood Test

If you are coming into one of our clinics for the test, this is what you need to do before you arrive:

  • Read the instructions in the SPECIAL INSTRUCTIONS section
  • Drink plenty of water about an hour before the appointment.
  • Avoid coffee/tea/energy drinks. Water is good!
  • That’s it! We’ll do the rest.

Home test kit - how it works with the Vitamin B12 (Active and Total) Blood Test

Our blood test kits are simple and convenient.

The most important step in doing a blood test at home is to read the instructions very carefully. The process is very simple, but there are a few pitfalls you need to be aware of - you will save yourself a lot of time if you do it right the first time around!

  • Full printed instructions will arrive with your kit - please read them carefully.
  • Drink plenty before taking the sample and warm your hands up in the sink with warm water for a few minutes. This will make your blood flow much better.
  • Fill the tubes to the top line. We don’t need much blood; filling tubes to the top line is about 15 drops of blood.
  • Post the samples on the same day you take them, before midday, Monday to Thursday. If you post it any other time it might get to us late or be stuck at a sorting office over the weekend. You will then have to do it again.
  • Package the sample in the same box the kit came in. Otherwise, Royal Mail or DPD will reject it. The sample tubes go into a pouch, then into a cardboard box, and then into a return envelope. All of this is provided in the kit: please use it.

We look forward to receiving your sample in our lab!

HOW OUR HOME KITS WORK

How the finger prick home blood test kit for Vitamin B12 (Active and Total) Blood Test works - from Dr. Adam Staten

Follow our step by step instructions on how to take your sample quickly and easily using the blood sample collection finger prick test.

WHY CHOOSE US?

Hello! My name is Dr. Vinesh Mistry, I am part of the GP team here at One Day Tests and here is why you should trust us to test your blood.

QUICK AND ACCURATE RESULTS DIRECT FROM A LABORATORY.

We run our own regulated laboratories and our own accredited clinics. We manufacture our own approved home sample collection kits. Your results are looked after by our fantastic clinical governance team and our super-talented biomedical science team.

When you book your test with us - you book directly with the lab. This means accuracy and responsible duty of care, direct access to the provider and extremely fast turnaround times.

Finally, our customer services rock! You can ask the lab a question any time or you can speak to a real human. You can email us on hello@onedaytests.com or give us a call on 0127 309 2844.

FREQUENTLY ASKED QUESTIONS

Hi, I am Lana Nela, Lead Nurse, and here is what we are frequently asked about this test.

FREQUENTLY ASKED QUESTIONS

Here are some of the most frequently asked questions about the Vitamin B12 (Active and Total) Blood Test.

What are the symptoms of vitamin B12 deficiency?

Common symptoms include fatigue, weakness, pale skin, numbness or tingling in the hands and feet, difficulty concentrating, memory problems, and mood changes.

If left untreated, a deficiency can lead to more serious neurological or haematological complications.

Who is most at risk for B12 deficiency?

People most at risk include older adults, vegans and vegetarians, individuals with gastrointestinal conditions like coeliac or Crohn’s disease, and those taking medications that affect absorption, such as metformin or antacids.

WHY HAVE THE TEST?

Hi, I am Nader Eldarf, I am a Biomedical Scientist in our laboratory and here is why it's important to take this test.

  1. WHY HAVE THE VITAMIN B12 (ACTIVE AND TOTAL) BLOOD TEST?

    A vitamin B12 blood test is important because B12 plays a crucial role in red blood cell formation, neurological function, and DNA synthesis.

    Deficiency can lead to serious health issues such as megaloblastic anaemia, nerve damage, cognitive decline, and mood disturbances.

    These effects can be subtle and progress over time, making early detection vital.

IS THIS TEST RIGHT FOR YOU?

Hi, I am Sandeep Patel, I am the Laboratory Director at One Day Tests. Here are the symptoms that you may wish to address with this test.

  1. IS THE VITAMIN B12 (ACTIVE AND TOTAL) BLOOD TEST RIGHT FOR YOU?

    A vitamin B12 blood test is right for you if you’re experiencing symptoms such as fatigue, weakness, memory issues, numbness or tingling in the hands and feet, or difficulty with balance, all of which can be signs of B12 deficiency.

    It is especially recommended for people in higher risk groups, including older adults, people with gastrointestinal conditions (like coeliac or Crohn’s disease), vegans and vegetarians, or people taking certain medications such as metformin or proton pump inhibitors.

    You can prevent long term complications by monitoring the levels of B12.

  1. SYMPTOMS AND TAGS

    Chronic fatigue, Fatigue, Headache and Tiredness

WHY ARE BLOOD TESTS IMPORTANT?

Health monitoring is very important, you are in charge of your health - look after it.