ARUP's Laboratory Test Directory

Vitamin B1 (Thiamine), Plasma : 0080389

Mnemonic: VIT B1 P

Ordering Recommendation: Do not use to determine thiamine deficiency.
Methodology: Quantitative High Performance Liquid Chromatography
Performed: Sun-Sat
Reported: 2-5 days
Specimen Required: Collect: Green (sodium or lithium heparin), lavender (EDTA), or pink (K2 EDTA).

Specimen Preparation: Separate plasma from cells within one hour of collection. Protect from light within one hour of collection, and during storage and transport. Transfer 3 mL plasma to an ARUP Amber 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.

Stability (collection to initiation of testing): After separation from cells: Ambient: Unacceptable; Refrigerated: 1 week; Frozen at -20°C: 6 months
Reference Interval:
8-30 nmol/L
Interpretive Data: Total thiamine, measured as thiamine (vitamin B1) and thiamine monophosphate, is reported. However, 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.
Note: Whole blood is the preferred specimen for thiamine assessment.  Approximately 80% of thiamine present in whole blood is found in red blood cells.  Refer to Vitamin B1 (Thiamine), Whole Blood (0080388).
CPT Code(s): 84425
Cross References: B1 Vitamin (Vitamin B1 (Thiamine), Plasma) , Thiamine (Vitamin B1 (Thiamine), Plasma) , Vitamin B1 (Thiamine), LC/MS/MS (Vitamin B1 (Thiamine), Plasma)