Vitamin B12: normal range & what your result means

Q: What are the symptoms of B12 deficiency?

Tiredness, pale skin, a sore red tongue, pins-and-needles or numbness, and poor concentration. Nerve symptoms make prompt treatment important.

Q: Who is at risk of low B12?

Vegetarians and vegans, older adults, people on certain medicines (like metformin or long-term acid reducers), and those with absorption problems (pernicious anaemia).

Vitamin B12 is needed for healthy blood and nerves. Deficiency is common in vegetarians and older adults and can cause anaemia and nerve symptoms.

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Typical adult reference range

Measure	Range
Normal	200–900 pg/mL
Borderline/low	< 200 pg/mL

What a HIGH result can mean

High B12 is usually harmless (often from supplements); rarely it needs a cause found

What a LOW result can mean

Low B12 can cause tiredness, a sore tongue, tingling/numbness and memory problems, and anaemia

Ranges vary by lab. Reference ranges are TYPICAL ADULT values and vary by laboratory, age, sex, pregnancy and the method used. Always read your result against the range printed on YOUR report, and let your doctor interpret it alongside your history.

Frequently asked questions

What are the symptoms of B12 deficiency?

Tiredness, pale skin, a sore red tongue, pins-and-needles or numbness, and poor concentration. Nerve symptoms make prompt treatment important.

Who is at risk of low B12?

Vegetarians and vegans, older adults, people on certain medicines (like metformin or long-term acid reducers), and those with absorption problems (pernicious anaemia).

Upload your report to MedDroid →

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MedDroid is an AI medical assistant and can make mistakes. It provides general health information, not a diagnosis or medical advice — always consult a qualified clinician. In an emergency, contact your local emergency number immediately.