Thiamin (Vitamin B1), Whole Blood
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Assessment of thiamin deficiency
Thiamin measurement in patients with behavioral changes, eye signs, gait disturbances, delirium, and encephalopathy; or in patients with questionable nutritional status, especially those who appear at risk and who also are being given insulin for hyperglycemia
High-Performance Liquid Chromatography (HPLC) with Fluorescence Detection
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Thiamin (Vitamin B1), WB
Thiamin Diphosphate (TDP)
Thiamin Pyrophosphate (TPP)
Thiamin Diphosphate (TDP)
Thiamin Pyrophosphate (TPP)
Specimen Type Describes the specimen type needed for testing
Whole Blood EDTA
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Amber vial (Supply T192)
Specimen Volume: 4 mL
1. Fasting-overnight (12-14 hours) (infants-draw prior to next feeding). Water can be taken as needed.
2. Invert 8 to 10 times to mix blood.
3. Transfer whole blood into amber vial to protect from light.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Glass vial, clotted specimen, washed erythrocytes, or anticoagulant other than EDTA
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Whole Blood EDTA||Frozen (preferred)||14 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Thiamin (vitamin B1) is an essential vitamin required for carbohydrate metabolism, brain function, and peripheral nerve myelination. Thiamin is obtained from the diet. Body stores are limited and deficiencies can develop quickly. The total thiamin pool in the average adult is about 30 mg. An intake of 0.5 mg per 1,000 kcal per day is needed to maintain this pool. Due to its relatively short storage time, marginal deficiency can occur within 10 days and more severe deficiency within 21 days if intake is restricted.
Approximately 80% of all chronic alcoholics are thiamin deficient due to poor nutrition. However, deficiency also can occur in individuals who are elderly, have chronic gastrointestinal problems, have marked anorexia, are on cancer treatment, or are receiving diuretic therapy.
The signs and symptoms of mild-to-moderate thiamin deficiency are nonspecific and may include poor sleep, malaise, weight loss, irritability, and confusion. Newborns breast fed from deficient mothers may develop dyspnea and cyanosis; diarrhea, vomiting, and aphonia may follow. Moderate deficiency can affect intellectual performance and well-being, despite a lack of apparent clinical symptoms.
Severe deficiency causes congestive heart failure (wet beriberi), peripheral neuropathy (dry beriberi), Wernicke encephalopathy (a medical emergency that can progress to coma and death), and Korsakoff syndrome (an often irreversible memory loss and dementia that can follow). Rapid treatment of Wernicke encephalopathy with thiamin can prevent Korsakoff syndrome. Symptoms of dry beriberi include poor appetite, fatigue, and peripheral neuritis. Symptoms of wet beriberi include cardiac failure and edema. Patients with Wernicke encephalopathy present with behavior change (confusion, delirium, apathy), diplopia (often sixth nerve palsies), and ataxia. A late stage, in which the patients may develop an irreversible amnestic confabulatory state, is referred to as the Wernicke-Korsakoff syndrome.
The response to thiamin therapy in deficient patients is usually rapid. Thiamin deficiency is a treatable, yet under diagnosed, disorder in the United States. A heightened level of awareness of the possibility of thiamin deficiency is necessary to identify, intervene, and prevent thiamin deficiency's dire consequences. It appears that no conditions are directly attributable to thiamin excess and that thiamin administration is safe except in extremely rare cases of anaphylaxis from intravenous thiamin.
Whole blood thiamin testing is superior to currently available alternative tests for assessing thiamin status. Serum or plasma thiamin testing suffers from poor sensitivity and specificity, and <10% of blood thiamin is contained in plasma. Transketolase determination, once considered the most reliable means of assessing thiamin status, is now considered an inadequate method. The transketolase method is an indirect assessment. Since transketolase activity requires thiamin, decreased transketolase activity is presumed to be due to the decrease of thiamin. However, the test is somewhat nonspecific, as other factors may decrease transketolase activity. Transketolase is less sensitive than HPLC, has poor precision, and specimen stability concerns.
Thiamin diphosphate is the active form of thiamin and is most appropriately measured to assess thiamin status. Thiamin diphosphate in circulating blood is present in erythrocytes, but is undetectable (present in very low levels) in plasma or serum. HPLC analysis of thiamin diphosphate in whole blood or erythrocytes is the most sensitive, specific, and precise method for determining the nutritional status of thiamin and is a reliable indicator of total body stores. This assay specifically targets and quantitates the active form of vitamin B1 (thiamin diphosphate) as an indicator of vitamin B1 status.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Values for thiamin diphosphate <70 nmol/L are suggestive of thiamin deficiency.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Vitamin supplementation and non-fasting specimens may result in elevated thiamin diphosphate concentrations.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Naidoo DP, Bramdev A, Cooper K: Wernicke's encephalopathy and alcohol-related disease. Postgrad Med J 1991;67;978-981
2. Herve C, Beyne P, Letteron PH, Delacoux E: Comparison of erythrocyte transketolase activity with thiamin and thiamin phosphate ester levels in chronic alcoholic patients. Clin Chim Acta 1995;234:91-100
3. Majumdar SK, Shaw GK, O'Gorman P, et al: Blood vitamin status (B1, B2, B6, folic acid, and B12) in patients with alcohol liver disease. Int J Vitam Nutr Res 1982;52:266-271
4. Ball GFM: Vitamins: their role in the human body. Oxford, Blackwell Publishing, 2004, pp 273-288
5. Brin M: Erythrocyte as a biopsy tissue for functional evaluation of thiamin adequacy. JAMA 1964;187:762-766
Method Description Describes how the test is performed and provides a method-specific reference
An aliquot of whole blood is slowly mixed with methanol to precipitate the proteins. Following centrifugation, an aliquot of the clarified supernatant is derivatized using alkaline potassium ferricyanide. The derivatized solution is then subjected to high-performance liquid chromatography, during which derivatized thiamin diphosphate is separated from other components. Quantitation is achieved by fluorometry. The fluorescence characteristics of the thiochrome derivative, together with its unique chromatographic mobility, provide a high level of specificity for this method.(Lynch PL, Young IS: Determination of thiamine by high-performance liquid chromatography. J Chromatogr A 2000;881:267-284; Mancinelli R, Ceccanti M, Guiducci MS, et al: Simultaneous liquid chromatographic assessment of thiamine, thiamine monophosphate and thiamine diphosphate in human erythrocytes: a study in alcoholics. J Chromatogr B 2003;789:355-363)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
2 days (not reported Saturday or Sunday)
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|85753||Thiamin (Vitamin B1), WB||In Process|