Vitamins & Nutrients
Vitamin B12 (Cobalamin)
Vitamins & Nutrients
Critical for nerve function and energy. Especially important for plant-based diets.
VAT-exempt medical service
Vitamin B12, also known as cobalamin, is involved in the metabolism of every cell in the human body. Because B12 must be obtained from the diet, people who eat little or no animal products, those with intestinal conditions, and older adults are at elevated risk of deficiency. Up to 20 % of the elderly population may have insufficient B12 levels. Early detection through blood testing allows timely supplementation before irreversible neurological damage occurs.
A B12 test is recommended if you experience unexplained fatigue, brain fog, mood changes, numbness or tingling in your hands and feet. It is especially important for vegans, vegetarians, people with celiac disease or inflammatory bowel conditions, those on long-term proton-pump inhibitors or metformin, and women who are pregnant or breastfeeding. Regular monitoring helps ensure adequate intake and absorption.
What a high value can mean
Elevated serum B12 is most often caused by excessive supplementation. In rare cases, high levels may indicate liver disease, certain blood cancers (such as polycythaemia vera) or kidney dysfunction. Symptoms can include skin rashes, nausea, dizziness and anxiety. Discuss persistently high values with your healthcare provider to rule out underlying conditions.
What a low value can mean
Low B12 suggests inadequate intake or impaired absorption and can lead to megaloblastic anaemia and progressive nerve damage. The serum test alone may miss mild deficiency, so a follow-up methylmalonic acid (MMA) or homocysteine test is recommended when results fall in the lower half of the reference range. Common causes include vegan diets, pernicious anaemia, celiac disease, SIBO and gastric bypass surgery.
No fasting is required. If you take high-dose folic acid supplements, inform us before testing as they can mask B12 deficiency. Bring valid ID to the lab. If you take a supplement containing biotin (often sold for hair and nails), pause it for two days before the test, as high doses can distort the result.
Order your test
Choose your test and pay online. Your lab referral is created straight away.
Give your sample
Visit any of our partner sampling locations. No appointment needed at most of them.
The lab analyses it
Your sample is analysed at an accredited Swedish laboratory.
Get your results
Your values appear in your account with reference ranges and an explanation of each marker.
Reference ranges vary by laboratory but typically fall between 200 and 600 pmol/L. Values in the lower half of the range may still indicate functional deficiency, especially if symptoms are present.
Yes. Serum B12 is limited in sensitivity. A methylmalonic acid (MMA) test measures B12 at the cellular level and can uncover deficiency missed by the serum test alone.
Treatment depends on severity and cause. Options include high-dose oral supplements, sublingual tablets or intramuscular injections. Your healthcare provider will recommend the best approach.
If you are at risk or supplementing, testing every 6 to 12 months is generally recommended. Your provider may suggest more frequent monitoring if levels were previously low.