Prealbumin (transthyretin)
Liver-made blood protein measured as a pointer to nutritional status
Also known as
Definition
Prealbumin, also called transthyretin, is a protein made in the liver that circulates in the blood. It carries thyroid hormones and vitamin A and is used to build other proteins. The blood test was long used to assess protein and nutrient supply, especially in seriously ill people. Because the level also drops with inflammation, infection and injury, its value as a nutrition marker is now debated.
| Parameter | Value |
|---|---|
| Unit | mg/dl or g/l |
| Reference Range | There is no single reference range; each lab sets it for its own method. The range printed on your report is what counts, and your doctor interprets the result. |
Agree on your personal target range with your doctor.
Conversion: 1 mg/dl = 0.01 g/l (10 mg/dl = 0.1 g/l).
↓ What a low value means
According to MedlinePlus, a low prealbumin level can be related to malnutrition, but also to inflammation, injuries such as burns, serious or long-term illness, liver disease, serious infection, an overactive thyroid or certain digestive diseases. In people who are ill, injured or recovering from surgery, the cause is often hard to pin down, and further tests usually follow. Discuss any deviation with your doctor.
↑ What a high value means
A high prealbumin level can be related to Hodgkin lymphoma, kidney failure, alcohol use disorder or high-dose corticosteroid treatment. According to MedlinePlus, however, the test is not used to diagnose or monitor these conditions. Certain medicines and pregnancy also affect the level, and not every deviation means something needs treatment. Discuss the result with your doctor.
When to test
The test is usually ordered for people at higher risk of malnutrition, for example in hospital, before or after surgery, with serious chronic illness, dialysis or artificial feeding, or with signs such as weight loss, weakness, dry skin and hair loss. No special preparation is needed. Mention all medicines you take beforehand and do not stop anything without talking to your doctor.
Frequently asked questions
What is the difference between prealbumin and albumin? +
Both are proteins made in the liver and measured in the blood. Prealbumin carries, among other things, thyroid hormones and vitamin A. Both values are affected by inflammation and are therefore always looked at together with other findings.
Does a low prealbumin level reliably show malnutrition? +
No. According to MedlinePlus, prealbumin also falls with inflammation, infection and injury. Many experts therefore no longer consider the test suitable for diagnosing malnutrition, while others still use it in seriously ill people. Interpreting it is a job for your doctor.
Do I need to fast for the test? +
According to MedlinePlus, no special preparation is needed. Some medicines can affect the result, so tell your doctor beforehand what you take.
Prealbumin (transthyretin)
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.