Iron & vitamins

Vitamin B12 unit converter

Cobalamin level

Also known as: B12, Cobalamin, Cyanocobalamin, Cobalamine, Cobalamina, Vitamine B12

Converter

Enter a value in any unit and all other units fill in.

pmol/L pg/mL nmol/L µg/L ng/dL

Worked example

496 pmol/L (middle of the reference range) = 672 pg/mL

Conversion formulas

pg/mL	pg/mL = pmol/L × 1.355	pmol/L = pg/mL × 0.738
nmol/L	nmol/L = pmol/L × 0.001	pmol/L = nmol/L × 1000
µg/L	µg/L = pmol/L × 0.001355	pmol/L = µg/L × 737.8
ng/dL	ng/dL = pmol/L × 0.1355	pmol/L = ng/dL × 7.378

Reference range

Unit	Adults
pmol/L	219 – 773
pg/mL	296.7 – 1047
nmol/L	0.219 – 0.773
µg/L	0.2968 – 1.048
ng/dL	29.68 – 104.8

Source: MedlinePlus (NLM): Vitamin B12 level · Last reviewed: 2026-10-14

Note from the source: 299-1054 pg/mL (219-773 pmol/L); below 299 pg/mL suggests deficiency, to be confirmed with methylmalonic acid (MedlinePlus)

Frequently asked questions

How do I convert Vitamin B12 from pmol/L to pg/mL?

pg/mL = pmol/L × 1.355. In the other direction: pmol/L = pg/mL × 0.738.

What is the reference range of Vitamin B12?

For adults the range is 219 – 773 pmol/L (MedlinePlus (NLM): Vitamin B12 level). Reference ranges differ between laboratories and partly by sex and age; use the range printed on your lab report.

Which units are used for Vitamin B12?

Common units are pmol/L, pg/mL, nmol/L, µg/L, ng/dL.