Vitamin B12 (Cyanocobalamin)
Vitamin B12 is essential for nerve function, DNA synthesis, and red blood cell production. Deficiency can cause anaemia, neurological damage, and cognitive problems. Vegetarians are at higher risk.
12 hours
Turnaround
Blood
Sample
What the Vitamin B12 (Cyanocobalamin) test tells you
Vitamin B12, also called cobalamin, is needed for two jobs the body cannot do without: building new DNA whenever a cell divides, and maintaining the fatty myelin sheath that insulates nerve fibres. Bone marrow and nerve tissue are therefore the first places a shortfall shows itself, which is why deficiency typically appears as anaemia, as neurological symptoms, or as both together.
Absorbing it is unusually elaborate. B12 comes almost entirely from animal foods such as meat, fish, eggs and dairy. Stomach acid first releases it from food, a protein called intrinsic factor made by the stomach lining then escorts it along the gut, and the pair are taken up together in the final section of the small intestine. A problem anywhere along that chain, whether autoimmune damage to the stomach lining, gastric or intestinal surgery, Crohn's disease affecting the ileum, or years of acid-suppressing medication, can produce deficiency even on a generous diet. The liver holds a substantial reserve, so a new shortfall can take years to declare itself.
The blood test measures the total amount of B12 in serum, most of which is bound to a carrier protein that does not hand it over to tissues. That is why symptoms sometimes persist alongside a comfortable-looking result, and why your doctor may add homocysteine or a folate measurement to judge whether the vitamin is actually working inside cells. The result is always interpreted with the blood count, the diet history, current medicines and the neurological examination rather than on its own.
Recommended for evaluating fatigue, anaemia, neurological symptoms (tingling, numbness), cognitive decline, and for routine monitoring in vegetarians and the elderly.
B12 is required to build red cells. Without it the marrow produces unusually large, immature cells, a pattern the blood count often flags before anything else.
Tingling, numbness, burning feet or unsteady walking can reflect damage to the insulation around nerves, and B12 is among the first things checked.
B12 comes almost exclusively from animal foods, so vegans and long-term vegetarians are monitored even when they feel well.
Metformin and acid-suppressing drugs taken over years reduce how much B12 is absorbed, which makes periodic testing sensible.
Reasons your doctor may request the Vitamin B12 (Cyanocobalamin) test
Your doctor may order this test for any of the reasons below. Some are routine checks, others follow specific symptoms or an earlier result.
Anaemia & nerve symptoms
Fatigue, breathlessness or pallor being investigated as possible anaemia.
Tingling, numbness, burning or unsteadiness affecting the hands and feet.
Blood count findings & cognitive symptoms
A blood count showing unusually large red cells or a low count without an obvious cause.
Memory difficulty, confusion or low mood being assessed, particularly in an older adult.
Diet, medication & previous surgery
A vegan or long-term vegetarian diet, or a breastfed infant whose mother follows one.
Years of metformin or acid-reducing medication, or previous stomach or bowel surgery.
No fasting window — pick any slot that suits you, online or on WhatsApp.
A DHA-licensed nurse collects your sample at home or in the office — free home collection.
A physician-reviewed, easy-to-read report lands securely by WhatsApp and email.
Vitamin B12 is essential for nerve function and red blood cell formation.
Ranges are a guide — your physician interprets your result alongside your symptoms and history.
What a higher result can point to
- Recent B12 injections, tablets or high-dose multivitamins, which lift the measured level for a long time afterwards.
- Liver disease, which releases stored B12 and its carrier proteins into the circulation.
- Reduced kidney function, which slows clearance of the carrier proteins.
- Certain bone marrow disorders, which increase production of the proteins that bind B12.
- Interference from antibodies in the sample, occasionally seen in pernicious anaemia, which can falsely raise the value.
What a lower result can point to
- A vegan or strongly plant-based diet without fortified foods or a supplement.
- Pernicious anaemia, where the immune system attacks the stomach cells that make intrinsic factor.
- Atrophic gastritis or long-term acid suppression, which prevent B12 from being released from food.
- Disease or surgical removal of the final part of the small intestine, as in Crohn's disease or bowel resection.
- Gastric bypass or other weight-loss surgery, which bypasses much of the absorptive route.
- Long-term metformin therapy, which gradually reduces absorption.
These are possibilities, not diagnoses. A single value outside the reference range is interpreted alongside your symptoms, history and other tests — your doctor decides what it means for you.
What this test cannot tell you
- The test measures total B12, including the large share bound to a carrier that does not deliver it to cells, so a reassuring result does not always mean tissue supply is adequate.
- Recent supplements or an injection raise the measurement and can mask a genuine deficiency for months.
- Folate supplementation can correct the anaemia of B12 deficiency while nerve damage quietly continues, so the two are usually assessed together.
- Pregnancy lowers the measured value without necessarily indicating deficiency.
Risks of the blood draw
- Mild bruising or brief soreness where the needle went in.
- Occasional lightheadedness, which settles after a few minutes of rest.
- Bleeding or infection at the site, which is rare with sterile single-use equipment.
- 1B12 is essential for red cell production and for the insulating sheath around nerves.
- 2It comes almost entirely from animal foods and needs a healthy stomach and ileum to be absorbed.
- 3Liver stores are large, so a deficiency can develop quietly over years before symptoms appear.
- 4A result that looks acceptable does not always rule out a functional shortfall; homocysteine can help clarify.
- 5Nerve symptoms can progress even when there is no anaemia, or when folate has corrected it.
Frequently Asked Questions
Everything you need to know about the Vitamin B12 (Cyanocobalamin) test. Can't find what you're looking for?
Talk to our team→Yes. Most B12 in the blood is bound to a carrier protein that does not release it to cells, so the total can look fine while the amount actually available is not. If your symptoms suggest deficiency, your doctor may add homocysteine or other markers that reflect what is happening inside cells.
B12 is made by bacteria and reaches us almost entirely through animal foods, so a diet without meat, fish, eggs or dairy provides very little unless fortified foods or a supplement are included. Risk rises the longer the diet is followed, as liver stores are gradually used up.
Usually a long time. The liver holds a large reserve that can cover normal needs for years after intake or absorption falls, which is why the problem often surfaces gradually and why symptoms may appear well before anyone thinks to check.
They can. Folate corrects the anaemia caused by B12 deficiency, so the blood count improves while the nerve damage carries on unnoticed and untreated. This is why folate and B12 are generally measured and considered together rather than one in isolation.
Vitamin B12 is essential for nerve function, DNA synthesis, and red blood cell production. Deficiency can cause anaemia, neurological damage, and cognitive problems. Vegetarians are at higher risk.
Recommended for evaluating fatigue, anaemia, neurological symptoms (tingling, numbness), cognitive decline, and for routine monitoring in vegetarians and the elderly.
No, fasting is not required for the Cobalamin (B12) test, so you can eat and drink normally beforehand.
The Cobalamin (B12) test uses a blood sample, collected quickly by our DHA-licensed phlebotomist with minimal discomfort.
Results for the Cobalamin (B12) test are typically ready within 12 hours. You will receive a secure digital report, and your Smart Report highlights anything outside the normal range.
The Cobalamin (B12) test is AED 219, which includes free home sample collection and a physician-reviewed report. You can also build a custom panel and pay only for the markers you choose.
Yes. A DHA-licensed phlebotomist can collect your sample at home or the office anywhere in Dubai at no extra cost, 7 days a week. See how it works.
It is commonly chosen by all ages. If you are not sure it is right for you, our care team is happy to advise.
Add the Cobalamin (B12) test to your cart and complete the short booking wizard, choosing home collection or a lab visit. Guest checkout lets you book without creating an account.
Yes. It is processed at our EIAC-accredited laboratory (ISO 15189:2022) under DHA license 0046381 and verified by board-certified pathologists.
Every report includes reference ranges and plain-language notes. If you have questions, our care team can arrange a clinician review — just get in touch.
Absolutely. Add it to a curated health package or bundle it with any of our 160+ biomarkers, often from a single sample in one visit.