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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, in your blood.

Quick summary

["Riboflavin helps your body convert food into energy and supports vision, cell growth, and red blood cell production."]

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

Key facts at a glance

LOINC
39492-4
Short code
XR Ribs upper post-R Views
Synonyms
XR Ribs upper post-R 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 This Test May Be Ordered

Your healthcare provider may recommend this test if you have symptoms like skin rashes, sore throat, mouth ulcers, or vision problems that could be linked to low riboflavin levels. It may also be used to monitor vitamin deficiencies or check for conditions like alcoholism or malabsorption disorders that can affect vitamin absorption.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into your arm to draw blood. If you’re tested for plasma, your blood will be collected into a tube that separates plasma from cells. Avoid alcohol for 24 hours before the test if instructed.

What the Test Results Mean

Results are compared to a reference range for healthy individuals. Low levels might indicate vitamin deficiency, certain medical conditions, or poor dietary intake. High levels could be due to supplements or specific genetic factors.

Common Conditions Linked to Riboflavin Levels

Low riboflavin levels can be associated with conditions like alcoholism, celiac disease, or kidney disease. High levels may rarely suggest over-supplementation or certain genetic disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Riboflavin Level

Frequently asked questions

What causes low riboflavin levels?
Low riboflavin levels can result from poor diet, alcohol misuse, malabsorption issues (like celiac disease), or certain medications that interfere with vitamin absorption.
How long does it take to get results?
Test results are typically available within 1–3 business days, depending on your lab and healthcare provider’s workflow.
Can I take riboflavin supplements if my levels are low?
Yes, but always follow your healthcare provider’s advice. Supplements should be taken under supervision, especially if you have underlying health conditions or are on medications.
  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