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Also known as: Thyroxine-binding Prealbumin
Formal name: Transthyretin
Related tests: C-Reactive Protein

At a Glance

Why Get Tested?

Reasons for ordering the prealbumin test are undergoing reassessment as understanding of prealbumin is evolving. Historically, prealbumin has been ordered to help detect protein-calorie malnutrition and to monitor the effectiveness of parenteral (for example, intravenous) nutrition. Newer evidence suggests that the reasons for changes in prealbumin levels may be more complex and the test should not be interpreted as a simple indicator of nutritional status.

When to Get Tested?

No current consensus exists on when to get tested, although prealbumin may be ordered, along with assessments of nutritional intake, when a health practitioner suspects that someone is malnourished or is at risk of malnutrition.

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?


The Test Sample

What is being tested?

Prealbumin, also called transthyretin, is one of the major proteins in the blood and is produced primarily by the liver. Its functions are to carry thyroxine (the main thyroid hormone) and vitamin A throughout the body. This test measures the level of prealbumin in the blood.

Although commonly used as a marker of malnutrition, research is continuing in order to better understand the role(s) of prealbumin in the body, especially the reasons for changes observed during illness, and the clinical utility of prealbumin testing.

How is the sample collected for testing?

A blood sample is taken by a needle from a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

Common Questions

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Article Sources

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

Sources Used in Current Review

Johnson, A. (2007). Clinical indications for plasma protein assays: transthyretin (prealbumin) in inflammation and malnutrition. Clinical Chemistry and Laboratory Medicine. PDF available for download at through Accessed May 2013.

Parrish, C.R. (2006). Serum Proteins as Markers of Nutrition: What are we treating? Nutrition Issues in Gastroenterology. PDF available for download through Accessed May 2013.

Shenkin A. Serum Prealbumin: Is It a Marker of Nutritional Status or of Risk of Malnutrition? Clin Chem Dec 2006 vol. 52 no. 12 2177-2179. Available online at through Accessed March 2013.

Beck F. Prealbumin: A Marker for Nutritional Evaluation. Am Fam Physician. 2002 Apr 15;65(8):1575-1579. Available online at through Accessed May 2013.

Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2007, Pp 235-236.

Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Burtis CA, Ashwood ER, Bruns DE, eds. 4th edition, St. Louis: Elsevier Saunders; 2006, Pg 563.

Pagana and Pagana. Mosby's Manual of Diagnostic and Laboratory Tests. Fourth edition. Pp. 424-427.

Consensus Statement of the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition: Characteristics Recommended for the Identification and Documentation of Adult Malnutrition (Undernutrition). Jane V. White, PhD, RD, FADA; Peggi Guenter, PhD, RN; Gordon Jensen, MD, PhD, FASPEN; Ainsley Malone, MS, RD, CNSC; Marsha Schofield, MS, RD; the Academy Malnutrition Work Group; the A.S.P.E.N. Malnutrition Task Force; and the A.S.P.E.N. Board of Directors. J Acad Nutr Diet. 2012;112:730-738.

Sources Used in Previous Reviews

The National Kidney Foundation: Kidney Disease Outcomes Quality Initiative. Available online at through

Holland DC, Meers C, Lawlor ME, Lam M. Serial prealbumin levels as predictors of outcomes in a retrospective cohort of peritoneal and hemodialysis patients. Journal of Renal Nutrition, July 2001, 11(3).

National Kidney Foundation Work Group, Committee: National Kidney Foundation-Kidney Disease Outcomes Quality Initiative. Clinical practice guidelines for nutrition in chronic renal failure. American Journal of Kidney Disease, June 2000, 35(6 Suppl 2): S1-140.

Clinical Guide to Laboratory Tests. 3rd ed. Tietz N, ed. Philadelphia: W.B. Saunders & Co; 1995: 608-609.

Frey RJ. Anorexia nervosa. Gale Encyclopedia of Medicine. Gale Research, 1999.

Larry A. Broussard, PhD. Clinical Laboratory Sciences, LSU Health Sciences Center, New Orleans, LA.

Pagana, K. D. & Pagana, T. J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 755-756.

Clarke, W. and Dufour, D. R., Editors (© 2006). Contemporary Practice in Clinical Chemistry: AACC Press, Washington, DC. Pp 197.

Banh, L. (2006 October). Serum Proteins as Markers of Nutrition: What Are We Treating? Practical Gastroenterology [On-line information]. PDF available for download at through Accessed June 2009.

Huckleberry, Y. (2004 May 03). Nutritional Support and the Surgical Patient. Medscape Today from American Journal of Health-System Pharmacy [On-line information]. Available online at through Accessed June 2009.

Beck, F. and Rosenthal, T. (2002 April 15). Prealbumin: A Marker for Nutritional Evaluation. American Family Physician [On-line information]. Available online at through Accessed June 2009.

Cassels, C. (2005 December 20). Hemodialysis, Prealbumin an independent predictor of mortality/morbidity. Medscape Medical News [On-line information]. Available online at through Accessed June 2009.