Metabolite and Retinol Erythrocyte Index (MREI) – Quantitative
This test measures a combination of metabolic markers and vitamin A levels in your blood, often used to assess nutritional status and metabolic health.
["Helps evaluate vitamin A stores and overall metabolic function in blood samples."]
Key facts at a glance
- LOINC
- 51635-1
- Short code
- Mat Retics #
- Synonyms
- Mat Retics #
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What This Test Measures
The MREI combines measurements of retinol (vitamin A) in your red blood cells and other metabolic substances. Retinol is a fat-soluble vitamin essential for vision, immune function, and cell growth. The test may also include related metabolites that reflect how your body processes nutrients.
Why It Might Be Ordered
Your healthcare provider may order this test if you have symptoms of vitamin A deficiency (such as night blindness or dry skin), suspected metabolic disorders, or if you’re undergoing treatment that could affect nutrient absorption.
Sample Preparation and Collection
A blood sample is drawn from a vein, typically in your arm. The sample is processed into either serum (after clotting) or plasma (using an anticoagulant). This test is usually performed on fresh or refrigerated samples within 24 hours of collection.
Common Reasons for Testing
Common indications include evaluating nutritional deficiencies, monitoring chronic conditions like liver disease or malabsorption syndromes, or assessing vitamin A status in patients with suspected metabolic disorders.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low MREI levels may indicate vitamin A deficiency or metabolic dysfunction, potentially leading to impaired vision, weakened immunity, or other systemic issues. Elevated levels could suggest liver disease, overconsumption of vitamin A supplements, or other metabolic abnormalities. Regular monitoring helps manage long-term health risks associated with these conditions.
Short name
MREI (Serum/Plasma)
Frequently asked questions
What does an abnormal MREI result mean?
How often should I get this test?
Can I take supplements before the test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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