3 - 5 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Whole blood, frozen and protected from light
0.2 mL (Note: This volume does not allow for repeat testing.)
EDTA (lavender top) whole blood, preferred. Also acceptable are lithium heparin (green-top) whole blood and sodium heparin (light green-top) whole blood.
The blood is to be collected by venipuncture into a lavender-top tube containing EDTA and mixed immediately by gentle inversion at least six times to ensure adequate mixing. Do not separate. Transfer whole blood to a labeled amber plastic transport tube with amber stopper and freeze. For amber plastic transport tube and amber stopper, order Labcorp No. 23598.
If amber tubes are unavailable, cover standard transport tube completely, top and bottom, with aluminum foil. Identify specimen with patient's name directly on the container and the outside of the aluminum foil. Secure with tape.
To avoid delays in turnaround time when requesting multiple test on frozen samples, please submit separate frozen specimens for each test requested.
Specimens should be light-protected, stored frozen immediately, and maintained frozen during shipping.
Receipt of non-frozen sample; receipt of plasma or serum specimen; receipt of specimen not protected from light
Detect vitamin B2 deficiency
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)
137−370 µg/L (Note: Reference interval reflects Flavin Adenine Dinucleotide (FAD), which accounts for approximately 90% of the total riboflavin in whole blood.)
Vitamin B2 refers to a family of water-soluble flavin vitamins that are critical for metabolism and energy generations in the aerobic cell, through oxidative phosphorylation.1-4 These compounds are synthesized in plants and microorganisms and occur naturally in three forms: the physiologically inactive riboflavin, and the physiologically active coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). FAD accounts for about 90% of the total riboflavin in tissues. Because of their capacity to transfer electrons, FAD and FMN are essential for proton transfer in the respiratory chain, for the dehydration of fatty acids, the oxidative deamination of amino acids, and for other redox processes.1-4 The effects of riboflavin deficiency on growth and development have generally been explained in terms of these functions. Flavin derivatives ingested with the diet (FAD, FMN) are dissociated by gastric acid from their protein binding, transformed by phosphatases to riboflavin, and absorbed in the small intestines.1,2 The reconversion of riboflavin to the coenzymes FMN and FAD occurs in the cytoplasm in many different tissues.
Vitamin B2 deficiency is common in many parts of the world, particularly in developing countries.1,5,6 Several studies have indicated that vitamin B2 deficiency may be widespread in industrialized countries as well, both in the elderly7,8 and in young adults.9 Dietary deficiency of riboflavin is characterized by lesions on the lips and the angles of the mouth, fissured and magenta-colored tongue, corneal vascularization and normocytic, normochromic anemia.1-4 Skin lesions include red scaly, greasy patches on the nose, eyelids, scrotum, and labia and seborrheic dermatitis.1-4 These symptoms are a consequence of oxidation stress due to the accumulation of lipid peroxides. Vitamin B2 deficiency leads to reduced activity of the flavin-containing enzymes (glutathione reductase and glutathione peroxidase) which, in turn, allows these peroxidase to express their deleterious effects.
Vitamin B2 is involved in the metabolism of folate, vitamin B12, vitamin B6, and other vitamins.10 Plasma vitamin B2 is a determinant of plasma homocysteine level, which is associated with cardiovascular disease, pregnancy complications, and cognitive impairment.10 Recent studies have suggested that riboflavin may play an important role in the determination of cell fate, which would have implications for growth and development.3 Specifically, riboflavin deficiency impairs the normal progression of the cell cycle, probably through effects on the expression of regulatory genes, exerted at both the transcriptional and proteomic level.3
No case of riboflavin toxicity in humans has been reported.
|Order Code||Order Code Name||Order Loinc||Result Code||Result Code Name||UofM||Result LOINC|
|123220||Vitamin B2, Whole Blood||6695-1||123221||Vitamin B2, Whole Blood||ug/L||6695-1|
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