Ordering Recommendation

Do not use for evaluation of thiamine sufficiency. Refer to Vitamin B1 (Thiamine), Whole Blood (0080388) for nutritional assessment of thiamine.


Quantitative High Performance Liquid Chromatography




2-4 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation

Green (sodium or lithium heparin), lavender (EDTA), plasma separator tube, or pink (K2 EDTA).

Specimen Preparation

Separate plasma from cells within one hour of collection. Transfer 1 mL plasma to an ARUP Standard Transport Tube. (Min: 0.2 mL)

Storage/Transport Temperature

Frozen. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

Hemolyzed specimens or specimens other than heparin or EDTA plasma.


After separation from cells: Ambient: Unacceptable; Refrigerated: 1 week; Frozen at -20°C: 6 months

Reference Interval

4-15 nmol/L

Interpretive Data

Thiamine (vitamin B1) is reported. However, thiamine diphosphate (TDP), the biologically active form of thiamine, is not found in measurable concentrations in plasma, and is best determined in whole blood specimens. Plasma thiamine concentration reflects recent intake rather than body stores.

Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.


Whole blood is the preferred specimen for thiamine assessment. Approximately 80 percent of thiamine present in whole blood is found in red blood cells. Refer to Vitamin B1 (Thiamine), Whole Blood (0080388).

Hotline History
CPT Codes


Component Test Code* Component Chart Name LOINC
0080389 Vitamin B1, Plasma 20468-5
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • B1 Vitamin
  • Thiamine
  • Vitamin B1 (Thiamine),
  • VITB1
Vitamin B1 (Thiamine), Plasma