Ordering Recommendation

Use to assess elevated vitamin C concentrations associated with therapeutic intravenous infusion of vitamin C. 

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Green (sodium or lithium heparin). Place specimen in ice bath immediately. Also acceptable: Plasma separator tube.

Specimen Preparation

Protect from light, centrifuge, transfer plasma, and freeze within 1 hour of collection. Transfer 0.5 mL plasma to an ARUP amber transport tube. (Min: 0.3 mL)

Storage/Transport Temperature

CRITICAL FROZEN AND LIGHT PROTECTED. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

EDTA plasma, whole blood, or body fluids. Grossly hemolyzed specimens.


Thawing and refreezing of the specimen and exposure to light will result in decreased vitamin C concentration.


After separation from cells: Ambient: Unacceptable; Refrigerated: Unacceptable; Frozen: 1 month


Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry




1-6 days

Reference Interval

Test Number
Reference Interval
  Vitamin C, Plasma 23-114 µmol/L

Interpretive Data

Intravenous vitamin C (IVC) administration produces millimolar plasma ascorbate (vitamin C) concentrations. Therapeutic concentrations average 15 mmol/L and range from 1-30 mmol/L. The maximum plasma concentration achieved by oral supplementation of vitamin C is approximately 250 µmol/L.

Vitamin C concentration is reported as micromoles per liter (µmol/L). To convert concentration to millimoles per liter (mmol/L), multiply the result by 0.001.

Compliance Category

Laboratory Developed Test (LDT)


Thawing and refreezing of the specimen and exposure to light will result in decreased vitamin C concentration.

Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
0080380 Vitamin C, Plasma 1903-4
* 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.


  • Ascorbate
  • Intravenous Vitamin C
  • IVC
Vitamin C, Plasma (High-Dose Therapy)