Vitamin B1 (Thiamine), Plasma
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.
Submit With Order
ARUP Consult®
Disease Topics
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
Component Test Code*Component Chart NameLOINC
0080389Vitamin B1, Plasma20468-5
* 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