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Serum flavin concentration (vitamin B2/riboflavin)

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

This test measures the amount of riboflavin (vitamin B2), a water-soluble vitamin essential for energy production and red blood cell health. Low levels may indicate malabsorption or underlying health conditions.

Quick summary

["Riboflavin helps your body produce energy and supports healthy skin, eyes, and red blood cells."]

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

Key facts at a glance

LOINC
79573-2
Short code
Flavins Pnl SerPl
Synonyms
Flavins Pnl SerPl
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 This Test Be Ordered?

Your healthcare provider may recommend this test if you have symptoms like skin rashes, mouth sores, vision problems, or fatigue. It’s also used to check for conditions affecting vitamin absorption, such as celiac disease or certain gastrointestinal disorders.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. The test is quick and typically done in a lab setting.

What the Results Mean

Results help determine if your body isn’t absorbing enough riboflavin. Low levels may prompt further testing for conditions like vitamin deficiencies or digestive issues.

Common Conditions Linked to Riboflavin Deficiency

Low riboflavin levels can be linked to conditions like alcoholism, certain medications (e.g., anticonvulsants), or digestive disorders. Severe deficiency may cause neurological or eye problems.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Riboflavin plays a key role in metabolism and cell function. Deficiency can impair energy production and may contribute to chronic fatigue or neurological symptoms if untreated.

Short name

Serum riboflavin level

Frequently asked questions

Why do some people need this test?
Your doctor may order it if you have symptoms like sore throat, red or swollen tongue, or unusual fatigue, especially if you’ve had recent changes in diet or medications.
What does a low or high result indicate?
A low result suggests possible vitamin deficiency or malabsorption, while high results may indicate liver disease or certain medications that increase riboflavin metabolism.
Can I take supplements to raise my riboflavin levels?
Yes, but consult your doctor first. Riboflavin supplements can help, but they shouldn’t replace addressing underlying causes like poor nutrition or digestive issues.
  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