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Serum or plasma concentration of riboflavin (vitamin B2)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of riboflavin, a vitamin essential for energy production and healthy skin, eyes, and nervous system. Low levels may indicate poor absorption or underlying health conditions.

Quick summary

["Riboflavin helps your body produce important compounds for energy and cell function; low levels may signal vitamin deficiency or metabolic issues."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
26152-9
Short code
XR Ribs-L Views
Synonyms
XR Ribs-L Views
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Might You Need This Test?

Your healthcare provider may order this test if you have symptoms like skin rashes, vision problems, or fatigue, especially if you have conditions like celiac disease, alcohol use, or certain medications that affect vitamin absorption.

What to Expect During Testing

A blood sample is taken from a vein in your arm. The sample is sent to a lab where riboflavin levels are measured using an immunoassay method. Results are typically available within 24–48 hours.

Possible Causes of Low or High Levels

Low riboflavin levels can result from dietary deficiencies, malabsorption disorders, or certain medications. High levels are less common but may occur with excessive vitamin intake.

Common Conditions Linked to Riboflavin Levels

Riboflavin deficiency is rare in healthy individuals but can occur in people with chronic illnesses, those on long-term antibiotics, or those with limited dietary intake of foods like dairy, eggs, and leafy greens.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Riboflavin plays a key role in metabolism and cell function. Abnormal levels may signal vitamin deficiency, metabolic disorders, or conditions affecting nutrient absorption. Your doctor may use these results to guide treatment, such as dietary changes or vitamin supplements.

Short name

Riboflavin Level

Frequently asked questions

Could riboflavin levels affect my energy levels?
Yes, riboflavin supports energy production in your cells. Very low levels may contribute to fatigue, but other factors like diet, sleep, and overall health also play a role.
Do I need to prepare for this test?
No special preparation is usually needed, but avoid alcohol for 24 hours before testing if advised by your doctor.
What if my results are outside the normal range?
If your results are low, your doctor may recommend dietary adjustments, supplements, or further testing to identify the cause. High levels are less common and may require investigation for over-supplementation or other conditions.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy