Vitamin B12 test: normal level, deficiency and symptoms
Medically reviewed by Dr. N. S. Santosh Varma, MBBS, FIM, FIDM, FICCM · Reg. APMC/FMR 112686 · Updated the day of publishing
A vitamin B12 test measures the B12 level in your blood. Many labs report about 200–900 pg/mL as normal; below about 200 pg/mL suggests deficiency and 200–300 is borderline. B12 deficiency is common in vegetarians, older adults and people on metformin or acid-reducing medicines, and can cause tiredness, tingling and memory problems.
B12 levels explained
| Level (pg/mL) | Usual meaning |
|---|---|
| Below about 200 | Deficiency likely |
| About 200–300 | Borderline; doctor may add more tests |
| About 300–900 | Usually normal |
Reference ranges differ slightly between labs, by age and by sex; always read the range printed on your own report and ask a doctor to interpret it.
Who is at higher risk
- Vegetarians and vegans
- Adults over 50
- People taking metformin or acid-reducing tablets for a long time
- People with stomach or bowel conditions
Symptoms
- Tiredness and weakness
- Tingling or numbness in hands and feet
- Poor memory or low mood
- Pale skin, sore tongue
- Anaemia with large red cells on a CBC
Is it included in YIRA's checkup?
This test is not part of YIRA's 70-test checkup. The doctor consultation included in every YIRA Family Health Plan can advise whether you need it, based on your results and history.
Your CBC can give a clue: large red cells (high MCV) can point to low B12.
A YIRA Family Health Plan includes a 70-test full body checkup at home for one registered member, a doctor consultation for the family, a review of an elder's past reports, and dental and eye check-ups. Essential ₹999 a year (up to 4 family members registered); Complete ₹1,299 a year (up to 8, with ₹5 lakh accident cover for the buyer).
70-test checkup at home plus family care, from ₹999 a year
Essential ₹999 (one 70-test checkup, up to 4 family members registered) · Complete ₹1,299 (up to 8, with ₹5 lakh accident cover). Doctor consultation, dental and eye check-ups included. Pay after sample collection.
Frequently asked questions
Do I need to fast for a vitamin B12 test?
Often 6 to 8 hours of fasting is advised, but follow your lab's instruction.
Can vegetarians get enough B12?
Milk, curd and paneer provide some B12, but many vegetarians still run low. A doctor may advise supplements.
How long does it take to correct B12 deficiency?
Levels often improve within weeks of treatment, but nerve symptoms can take months. Follow your doctor's plan.
Related
Medically reviewed by Dr. N. S. Santosh Varma (MBBS, FIM, FIDM, FICCM; APMC/FMR 112686). Prepared by the YIRA health team · Last updated 1 October 2026. This page is general health information, not medical advice or a diagnosis. Reference ranges differ between labs; always discuss your results with a doctor. In an emergency, call 108 or go to the nearest hospital.