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Vitamin B12 (Cobalamin) Unit Converter
Vitamin B12 (Cobalamin) is a water-soluble vitamin essential for red blood cell formation, neurological function, and DNA synthesis. It is primarily obtained from animal-based foods.
Deficiency can lead to megaloblastic anemia and irreversible neuropathy. While the United States typically uses mass units (pg/mL), many other countries use the SI molar unit (pmol/L). This converter facilitates accurate interpretation of B12 levels across different reporting standards.
Mass Units
StandardPicograms per milliliter (Common US Unit).
SI Units / Molar
Picomoles per liter (International Standard).
Clinical Context
Reference Ranges (Serum):
• Normal: 200 – 900 pg/mL (148 – 664 pmol/L).
• Borderline: 150 – 200 pg/mL.
• Deficiency: < 150 pg/mL.
Note: In borderline cases, measuring Methylmalonic Acid (MMA) is recommended, as elevated MMA is a more sensitive indicator of B12 deficiency.
Conversion Logic:
Molecular Weight of Cyanocobalamin: ~1355.4 g/mol.
1 pg/mL ≈ 0.738 pmol/L.
1 pmol/L ≈ 1.355 pg/mL.
Clinical References
How to Use This Converter
Follow these steps to normalize Vitamin B12 values.
Enter Values
Input your laboratory result into the corresponding unit field (e.g., pg/mL).
Automatic Conversion
The calculator converts between mass units and the SI molar unit using the molecular weight of 1355.4 g/mol.
Reset
Use the Clear button to reset all fields.
Frequently Asked Questions
Yes. 1 picogram per milliliter is numerically identical to 1 nanogram per liter.
High B12 is typically not toxic, but very high levels without supplementation can sometimes indicate underlying conditions like liver disease or myeloproliferative disorders.