Vitamins and minerals
What is Vitamin B12?
needed for nerves and red cells
- Unit
- pmol/L
- Sample
- Serum
- Fasting
- No fasting needed
- Turnaround
- 2 days
Vitamin B12 is needed for red cell formation and nerve function. Deficiency is more common in vegans, older people, and those with certain stomach conditions.
B12 occurs naturally only in animal foods but is added to fortified products. Uptake requires intrinsic factor made in the stomach, while the actual absorption happens in the last part of the small intestine. Low stomach acid or atrophic gastritis impairs absorption.
What does low Vitamin B12 mean?
Low B12 produces fatigue, tingling in hands and feet, difficulty concentrating, and in severe cases anaemia. Holotranscobalamin (active B12) is a more sensitive measure.
What does high Vitamin B12 mean?
High B12 most often follows supplementation or injection and is usually not a clinical concern.
Panels that measure Vitamin B12
- Vitamin Test Base
- Health Check Base
- Vitamin Test Complete
- Health Check Plus
- Iron Test Complete
- Performance Test Complete
- Health Check Complete
- Health Check Man
- Health Check Kvinna
Reading
- Tired all the time? The blood values that can explain why
- Trying for a baby: the blood tests worth taking first
- Vitamin D deficiency: symptoms, levels and what the Swedish winter does
- Normal TSH but still tired: what could be behind it?
- What is included in a blood test health check?
- Blood tests without a referral: how it works in Sweden
More markers in the same area
Launching in Stockholm in 2026.
Want to know when you can order?
This is general information about the marker, not an assessment of your values and not medical advice. Last updated: August 2026.