Prealbumin (Transthyretin)
Prealbumin testing evaluates nutritional status, protein metabolism, and can help monitor recovery from illness or malnutrition.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
Prealbumin, also known as transthyretin, is a protein produced primarily by the liver that transports thyroid hormones (thyroxine) and vitamin A (via retinol-binding protein) through the bloodstream. It has a short half-life of approximately two days, which means its blood concentration responds quickly to changes in protein synthesis and nutritional intake.
This rapid turnover is what makes prealbumin particularly useful as a nutritional marker. Albumin, the more commonly tested protein, has a half-life of roughly 20 days, so it takes weeks to reflect a change in nutritional status. Prealbumin captures changes within days, making it a more sensitive indicator of acute nutritional decline or improvement. Healthcare providers frequently use prealbumin to monitor nutritional status in critically ill or hospitalized patients, track response to nutritional support interventions, and identify individuals at risk of protein-calorie malnutrition.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals with chronic illnesses that may affect nutritional status, such as liver disease, kidney disease, or inflammatory conditions.
- Patients recovering from surgery, trauma, or serious infections who need monitoring of their nutritional recovery.
- Those receiving total parenteral nutrition (IV feeding) or specialized nutritional support who require monitoring of protein metabolism.
- People with suspected malnutrition or protein-energy deficiency who need assessment of their nutritional status.
- Individuals with unexplained weight loss or poor appetite who may benefit from nutritional evaluation.
What to expect
Preparation
No special preparation is needed for this test. No fasting is required. Continue taking medications as prescribed unless your healthcare provider advises otherwise.
Sample Type
A healthcare professional will collect a blood sample from a vein in the arm using a small needle. The procedure typically takes less than five minutes.
Collection
During the blood draw, individuals may feel a slight sting when the needle is inserted. After collection, there may be minor soreness at the needle site, but this usually resolves quickly.
Turnaround
Results are typically available within 1-3 business days after the laboratory receives the sample.
Understanding your results
Normal prealbumin levels typically range between 15 and 40 mg/dL, though reference ranges may vary by laboratory. Levels below 15 mg/dL may indicate protein-calorie malnutrition or impaired liver synthesis, while levels below 10 mg/dL are associated with more severe nutritional deficit. Because prealbumin is a negative acute-phase reactant, its levels drop during inflammation, infection, and critical illness independent of nutritional status. Healthcare providers interpret prealbumin alongside albumin, CRP (to assess concurrent inflammation), dietary intake data, and the clinical situation to distinguish true malnutrition from inflammation-driven suppression.
| Population | Reference Range | Notes |
|---|---|---|
| Adults | 15-40 mg/dL | Normal range for healthy adults |
| Adult Males | 20-50 mg/dL | May be slightly higher than females |
| Adult Females | 10-40 mg/dL | May be affected by pregnancy and hormonal changes |
Reference ranges may vary by laboratory and individual factors. Results should be interpreted by a healthcare provider in the context of your overall health.
What does a “Low” result mean?
Low prealbumin levels typically indicate a need for nutritional assessment and may suggest malnutrition, liver disease, inflammation, or tissue damage. Low levels can also occur with infection, inflammatory conditions, and trauma, and elderly individuals may be at increased risk for decreased prealbumin levels. Certain medications and pregnancy can also affect prealbumin levels.
What does a “High” result mean?
Elevated prealbumin levels may be associated with chronic kidney disease, steroid use, or alcoholism. Higher values have also been observed in certain conditions like Hodgkin's disease. However, elevated levels are less common and may require further evaluation to determine the underlying cause.
Privacy & confidentiality
Test results are confidential and protected under HIPAA regulations. Results are not shared with insurance companies or added to your permanent medical records unless you specifically request this. No doctor visit required for testing.
Frequently asked questions
Related tests
Albumin
Often tested together to provide comprehensive protein status assessment
View TestC-Reactive Protein (CRP)
Helps interpret prealbumin results by identifying inflammation that may affect levels
View TestLiver Function Panel
Evaluates liver health since prealbumin is produced in the liver
View TestBasic Thyroid Panel
Prealbumin transports thyroid hormones, so thyroid function may be relevant
View TestRelated conditions
Last reviewed: April 2026
CPT Code: 84134
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
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