Vitamin B12 Deficiency Risk Calculator

Work out vitamin b12 deficiency risk instantly with clear inputs, formula shown and shareable results.

About Vitamin B12 Deficiency Risk Calculator

Bands a serum vitamin B12 level, converts it to SI units and notes when methylmalonic acid testing is needed to confirm functional deficiency.

Formula

B12 interpretation

pmol/L = pg/mL x 0.7378. Deficiency under about 150 pmol equivalent, indeterminate 150-300, with methylmalonic acid or homocysteine used to resolve the grey zone

Worked example

With the default values below, Vitamin B12 Deficiency Risk Calculator returns Vitamin B12 status of Borderline low (150 to 199). Change any input above and every figure here is recalculated in your browser.

Inputs used

Serum vitamin B12accepts 30–2,000 pg/mL: 180 pg/mL
Methylmalonic acid raisedone of Yes, No, Not measured: Not measured
Risk factors presentaccepts 0–6: 2

Results

Vitamin B12 status: Borderline low (150 to 199)
Suggested next step: Consider methylmalonic acid or homocysteine to confirm functional status
Risk factor burden: Some risk factors present
Level: 133 pmol/L

Step by step

1Values used
2B12 interpretation
3Vitamin B12 status= Borderline low (150 to 199)
4Suggested next step= Consider methylmalonic acid or homocysteine to confirm functional status
5Risk factor burden= Some risk factors present
6Level= 133 pmol/L

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

Why is the serum level unreliable?

Most circulating B12 is bound to haptocorrin and unavailable to cells, so functional markers detect deficiency the total level misses.

Which drugs deplete B12?

Long-term metformin and proton pump inhibitors both reduce absorption over years.