General Information

UPHSM LIS Test #: 6347
Testing Time:
Testing Lab: Labcorp

Specimen Info
Only 1 specimen type required, unless otherwise specified

Volume: 1.0 (0.5) mL Whole Blood
Temperature: Frozen
Tube Type: Lavender-top EDTA Light Protected
Collection Info:
Container:  Lavender-top (EDTA) tube; amber plastic transport tube with amber-top. (If amber tubes are unavailable, cover standard transport tube completely, top and bottom, with aluminum foil. Identify specimen with patient name directly on the container and on the outside of the aluminum foil. Secure with tape.)

Collection:  Draw blood. Do not separate. Protect specimen from light. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Storage Instructions:  Transfer whole blood to plastic transport tube and freeze. Protect from light.
Patient Preparation:  Blood samples should be collected before breakfast in the morning and prior to any medication.
Causes for Rejection:  Specimen not frozen; plasma specimen; use of anticoagulants other than EDTA; specimen not protected from light

Specimen Acceptability

The biologically active form of the vitamin, thiamine diphosphate (TDP), is best measured in whole blood and is not found in measurable concentration in plasma.  Plasma thiamine concentration reflects recent intake rather than body stores.


High-pressure liquid chromatography (HPLC) with fluorescence detector

Clinical Utilities

The classic vitamin B1 deficiency disease is beriberi, the primary symptoms of which are neurological and cardiovascular disturbances such as myocardial damage, cardiac failure, and neuritis and neural paralyses accompanied by metabolic dysfunction in the form of lactate acidosis and branched-chain ketoaciduria. Further thiamine deficiency diseases are Wernicke's encephalopathy, Korsakov's syndrome, and several forms of Landry's paralysis.

CPT Codes


* The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding
is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Reference Range

66.5-200.0 nmol/L