Vitamin B2 (Riboflavin) levels: what's normal, high and low
A B vitamin needed for energy production and red blood cell formation.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
Vitamin B2 (Riboflavin) is measured with a standard blood draw; no fasting is needed. A typical reference range is 137 – 370 nmol/L. At TestWell it's $66.99 all-in as Vitamin B2 (Riboflavin), results in 3–5 business days, drawn at Quest. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- nmol/L
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 3–5 business days
- Price
- $66.99
- Labs
- Quest
Vitamin B2 (Riboflavin) Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 137 – 370 nmol/L |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
What your Vitamin B2 (Riboflavin) result may mean
Can reflect inadequate dietary intake or malabsorption.
What a low Vitamin B2 (Riboflavin) means: causes, symptoms, next steps →Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
How do you get a Vitamin B2 (Riboflavin) test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. Vitamin B2 (Riboflavin) is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Vitamin B2 (Riboflavin) | This marker only | $66.99 |
Quest vs. Labcorp for Vitamin B2 (Riboflavin): which lab should you pick?
Both are CLIA-certified national labs and the result is clinically equivalent, so pick whichever location is closer. Your report will print that lab's own reference range, which can differ slightly from the table above.
| Lab | Available | Price |
|---|---|---|
| Quest Diagnostics | Yes | $66.99 |
| Labcorp | No | — |
| BioReference (NY & NJ) | No | — |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Related Vitamins & Nutrients biomarkers
Markers commonly tested alongside Vitamin B2 (Riboflavin).
Frequently asked
Can reflect inadequate dietary intake or malabsorption. A single result below the reference range is a prompt to look closer with a clinician — often a repeat test and related markers — not a diagnosis on its own.
Ready to test your vitamin b2 (riboflavin)?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $66.99.