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Vitamin C

CPT: 82180
Updated on 05/13/2020
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  • Ascorbic Acid
  • C, Vitamin

Expected Turnaround Time

3 - 5 days

3 - 5 days

Related Documents

Specimen Requirements


Plasma, frozen and protected from light


1 mL

Minimum Volume

0.5 mL (Note: This volume does not allow for repeat testing.)


Green-top (lithium heparin) 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.) For amber plastic transport tube and amber-top, order LabCorp No. 23594.


Collect blood by venipuncture into a green-top containing lithium heparin and mix immediately by gentle inversion at least six times to ensure adequate mixing. Plasma must be separated from cells immediately after venipuncture and transferred to light-protected amber plastic tube. Separated plasma must be placed on dry ice for shipment within 4 hours of separation. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

Storage Instructions

Freeze immediately and protect from light.

Stability Requirements



Room temperature





14 days

Freeze/thaw cycles

Stable x1

Causes for Rejection

Anticoagulants other than lithium heparin; specimen not protected from light

Test Details


Along with dietary history, evaluating serum ascorbic acid levels should be considered for patients with classic signs and symptoms of scurvy, as well as for those with common, nonspecific, chronic musculoskeletal complaints. Vitamin C deficiency is generally defined as plasma or serum concentrations less than 0.2 mg/dL, or the the level at which signs and symptoms of scurvy may appear. Serum ascorbic acid concentrations between 0.2 and 0.4 mg/dl are considered low.2,28,29


This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.


Liquid chromatography-tandem mass spectrometry (LC/MS-MS)

Additional Information

Vitamin C, also referred to as L-ascorbic acid, is a water-soluble vitamin that is naturally present in some foods, fortified in others, and available as a dietary supplement alone or in multivitamins.1,2 Humans, unlike most animals, cannot synthesize vitamin C de novo and must obtain it as an essential dietary component.1,3

Vitamin C a is required cofactor for the biosynthesis of a number of critical compounds.2,8 It is required for the function of several enzymes involved in the production of collagen, an essential component of connective tissue. These enzymes are required for the molecular cross-linking that gives collagen its elasticity. Vitamin C deficiency renders the polypeptide unstable and unable to self-assemble into rigid triple helices. Impaired collagen production can result in poor wound healing and a weakening of collagenous structures leading to tooth loss, joint pains and bone and connective tissue pathology and blood vessel fragility. Vitamin C also serves as a cofactor in the biosynthesis of carnitine, an essential compound for the transport of activated long chain fatty acids into the mitochondria. Vitamin C deficiency related reduction in carnitine levels results in fatigue and lethargy. Vitamin C is an essential cofactor for the conversion of dopamine to norepinephrine and in the metabolism of tyrosine and folate and the conversion of cholesterol to bile acids. In addition, vitamin C in the diet improves the absorption of non-heme iron, the form of iron present in plant-based foods.9

Profound and extended vitamin C deficiency leads to scurvy, a condition that is characterized by blood vessel fragility, connective tissue damage, fatigue, and, ultimately, death.1-13 Early symptoms can include weakness, listlessness, as well as shortness of breath and aching joints, bones and muscles. Myalgias occur because of the reduced production of carnitine. Oral complications can include gingival bleeding with minor trauma that proceeds to alveolar bone absorption and tooth loss. Iron deficiency anemia can also occur due to increased intestinal bleeding and decreased non-heme iron absorption.10-13 Rheumatologic problems, such as painful hemarthrosis and subperiosteal hemorrhage, may occur.12 Cardiac enlargement may occur because of congestive heart failure secondary to high-output anemia. Scurvy manifests when vitamin C intake falls below 10 mg/day for many weeks.10-13 Scurvy is rare in developed countries but can still occur in people with limited food variety and in other high risk groups.

Under physiological conditions, vitamin C serves as a potent antioxidant and has been shown to regenerate other antioxidants, particularly vitamin E.2,14-16 The reduced form of the vitamin, ascorbic acid, is a very effective antioxidant due to its high electron-donating power and ready conversion back to the active reduced form by glutathione.2 This antioxidant action plays a role in limiting the damage caused of free radicals produced by normal metabolic respiration and might serve to deter the development of certain cancers, cardiovascular disease, and other diseases.2,14-16 Vitamin C concentration has been shown to be inversely associated with all-cause mortality.17,27 Low plasma vitamin C concentrations are associated with increased blood pressure16,17 and an increased risk of cardiovascular disease9,15,18,21-23 and diabetes.24,25

The NHANES 2003-2004 revealed that approximately seven percent of the United States population has deficient serum levels of vitamin C (levels below 11 umol/L).28 The prevalence of vitamin C deficiency was markedly higher in smokers relative to nonsmokers, possibly due to the increased catabolism associated with the oxidative stress of caused by smoking.2,28 Lower vitamin C levels are seen in the institutionalized elderly, possibly due to clinical conditions such as recurrent infections.2 Levels are also lower in low-income compared with the high-income persons.28 Other at-risk groups include persons with gastroinestinal disease or poor dentition.2,12 Cancer patients on chemotherapy who have increased nausea and diarrhea are also at risk, as are patients on hemodialysis.12 Psychiatric disorders including depression, schizophrenia, or anorexia, also can put patients at risk for reduced intake of vitamin C.12 Alcoholic persons are at risk for scurvy because they may have poorly balanced diets and because decreases the absorption of vitamin C.12


1. Institute of Medicine (US) Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000.25077263
2. Jacob RA, Sotoudeh G. Vitamin C function and status in chronic disease. Nutr Clin Care. 2002 Mar-Apr;5(2):66-74.12134712
3. Li Y, Schellhorn HE. New developments and novel therapeutic perspectives for vitamin C. J Nutr. 2007 Oct;137(10):2171-2184.17884994
4. Burri BJ, Jacob RA. Human metabolism and the requirement for vitamin C. In: Packer L, Fuchs J, eds. Vitamin C in health and disease. New York, NY: Marcel Dekker; 1997:341-366.
5. Levine M, Rumsey SC, Daruwala R, Park JB, Wang Y. Criteria and recommendations for vitamin C intake. JAMA. 1999 Apr 21;281(15):1415-1423.10217058
6. Carr AC, Frei B. Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. Am J Clin Nutr. 1999 Jun;69(6):1086-1107.10357726
7. Rebouche CJ. Ascorbic acid and carnitine biosynthesis. Am J Clin Nutr. 1991 Dec;54(6 Suppl):1147S-1152S.1962562
8. Tsao CS. An overview of ascorbic acid chemistry and biochemistry. In: Packer L, Fuchs J, eds. Vitamin C in health and disease. New York, NY: Marcel Dekker; 1997:25-58.
9. Weber P, Bendich A, Schalch W. Vitamin C and human health—a review of recent data relevant to human requirements. Int J Vitam Nutr Res. 1996;66(1):19-30.8698541
10. Wang AH, Still C. Old world meets modern: a case report of scurvy. Nutr Clin Pract. 2007 Aug;22(4):445-448.17644699
11. Weinstein M, Babyn P, Zlotkin S. An orange a day keeps the doctor away: scurvy in the year 2000. Pediatrics. 2001 Sep;108(3):E55.11533373
12. Olmedo JM, Yiannias JA, Windgassen EB, Gornet MK. Scurvy: a disease almost forgotten. Int J Dermatol. 2006 Aug;45(8):909-13.16911372
13. Mertens MT, Gertner E. Rheumatic manifestations of scurvy: a report of three recent cases in a major urban center and a review. Semin Arthritis Rheum. 2011 Oct;41(2):286-290.21185063
14. Frei B, England L, Ames BN. Ascorbate is an outstanding antioxidant in human blood plasma. Proc Natl Acad Sci U S A. 1989 Aug;86(16):6377-6381.2762330
15. Gey KF. Vitamins E plus C and interacting conutrients required for optimal health. A critical and constructive review of epidemiology and supplementation data regarding cardiovascular disease and cancer. Biofactors. 1998;7(1-2):113-174.9523035
16. Arrigoni O, De Tullio MC. Ascorbic acid: much more than just an antioxidant. Biochim Biophys Acta. 2002 Jan 15;1569(1-3):1-9.11853951
17. Simon JA, Hudes ES, Tice JA. Relation of serum ascorbic acid to mortality among US adults. J Am Coll Nutr. 2001 Jun;20(3):255-263.11444422
18. Enstrom JE. Vitamin C in prospective epidemiological studies. In: Packer L, Fuchs J, eds. Vitamin C in health and disease. New York, NY: Marcel Dekker; 1997:381-398.
19. Moran JP, Cohen L, Greene JM, et al. Plasma ascorbic acid concentrations relate inversely to blood pressure in human subjects. Am J Clin Nutr. 1993 Feb;57(2):213-217.8424391
20. Myint PK, Luben RN, Wareham NJ, Khaw KT. Association between plasma vitamin C concentrations and blood pressure in the European prospective investigation into cancer-Norfolk population-based study. Hypertension. 2011 Sep;58(3):372-379.21768529
21. Pfister R, Sharp SJ, Luben R, Wareham NJ, Khaw KT. Plasma vitamin C predicts incident heart failure in men and women in European Prospective Investigation into Cancer and Nutrition-Norfolk prospective study. Am Heart J. 2011 Aug;162(2):246-253.21835284
22. Boekholdt SM, Meuwese MC, Day NE, et al. Plasma concentrations of ascorbic acid and C-reactive protein, and risk of future coronary artery disease, in apparently healthy men and women: the EPIC-Norfolk prospective population study. Br J Nutr. 2006 Sep;96(3):516-522.16925857
23. Myint PK, Luben RN, Welch AA, Bingham SA, Wareham NJ, Khaw KT. Plasma vitamin C concentrations predict risk of incident stroke over 10 y in 20 649 participants of the European Prospective Investigation into Cancer Norfolk prospective population study. Am J Clin Nutr. 2008 Jan;87(1):64-69.18175738
24. Sinclair AJ, Taylor PB, Lunec J, Girling AJ, Barnett AH. Low plasma ascorbate levels in patients with type 2 diabetes mellitus consuming adequate dietary vitamin C. Diabet Med. 1994 Nov;11(9):893-898.7705029
25. Paolisso G, D’Amore A, Balbi V, et al. Plasma vitamin C affects glucose homeostasis in healthy subjects and in non-insulin-dependent diabetics. Am J Physiol. 1994 Feb;266(2 Pt 1):E261-268.8141285
26. Schleicher RL, Carroll MD, Ford ES, Lacher DA. Serum vitamin C and the prevalence of vitamin C deficiency in the United States: 2003-2004 National Health and Nutrition Examination Survey (NHANES). Am J Clin Nutr. 2009 Nov;90(5):1252-1563.19675106
27. Loria CM, Klag MJ, Caulfield LE, Whelton PK. Vitamin C status and mortality in US adults. Am J Clin Nutr. 2000 Jul;72(1):139-145.10871572
28. U.S. Centers for Disease Control and Prevention. Second National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population (2012). Atlanta, GA: National Center for Environmental Health, Division of Laboratory Sciences; April 2012. Available at Accessed March 2020.
29. Gibson RS. Principles of nutritional assessment (2nd ed.). New York: Oxford University Press; 2005.


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
001805 Vitamin C 1903-4 001806 Vitamin C mg/dL 1903-4

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