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Vitamin D (Total) Unit Converter
Total Vitamin D (25-Hydroxyvitamin D) is the most accurate marker of Vitamin D stores in the body. It represents the sum of Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol).
While the United States reports results in mass units (ng/mL), most other countries use the International System (SI) molar units (nmol/L). This converter standardizes these values to help interpret deficiency, sufficiency, and toxicity.
Mass Units (US)
StandardNanograms per milliliter (Common US Unit).
SI Units / Molar
Nanomoles per liter (International Standard).
Clinical Context
Interpretation (Endocrine Society Guidelines):
• Deficiency: < 20 ng/mL (< 50 nmol/L).
• Insufficiency: 21 – 29 ng/mL (52.5 – 72.5 nmol/L).
• Sufficiency: 30 – 100 ng/mL (75 – 250 nmol/L).
• Potential Toxicity: > 100 ng/mL (> 250 nmol/L).
Conversion Logic:
Molecular Weight of 25(OH)D: ~400.64 g/mol.
1 ng/mL ≈ 2.496 nmol/L.
1 nmol/L ≈ 0.401 ng/mL.
Clinical References
How to Use This Converter
Follow these steps to normalize Vitamin D values.
Enter Values
Input your laboratory result into the corresponding unit field. Use ng/mL for US results or nmol/L for international.
Automatic Conversion
The calculator converts between mass units and the SI molar unit using the conversion factor of 2.496.
Reset
Use the Clear button to reset all fields.
Frequently Asked Questions
Yes. 1 nanogram per milliliter is numerically identical to 1 microgram per liter.
It includes both Vitamin D2 (from plants/fungi) and Vitamin D3 (from sun/animals). Both contribute to your overall Vitamin D status.