Vitamin B12 with Homocysteine and Methylmalonic Acid Reflexes

Overview

  • EPIC Code:
  • LAB3133
  • Soft Test Code:
  • B12R
  • Send Out Test Code:
  • 34879
Alternate Names
  • Vitamin B12 with Reflexes
Included Tests

Homocysteine; Methylmalonic Acid; Vitamin B12 (B12)


Included Tests References:
Clinical Significance

Homocysteine and Methylmalonic Acid, in conjunction with Vitamin B12, may be useful for the identification of early or subclinical Vitamin B12 deficiency.


Specimen Collection & Preparation

Patient Preparation

12 hours Fasting is recommended, but not required


Specimen Requirements:

-OR-

4.0 mL Serum from a SST Gold Top Tube placed in Opaque Transport Bag
Minimum Volume:
2.0 mL Serum*

* This volume does not allow for repeat testing

Processing Instructions:

Centrifuge and separate from cells within 2 hours of collection
Protect from light by placing in a black opaque transport bag


Transport and Storage:
  • Ambient (18-24°C): 2 Hours
  • Refrigerated (2-8°C): 48 Hours

    Transport refrigerated

Clinical Interpretation

Reference Range:

Vitamin B12: 200 - 900 pg/mL

Reflex Homocysteine:

(Adult < 60 years of age): 4.5 - 15 umol/L

Methylmalonic Acid: 87 - 318 nmol/L


Test Comments:

A Homocysteine and Methylmalonic Acid will automatically be performed and charged when the Vitamin B12 is 150 - 400 pg/mL. 

B12: Patients taking vitamin supplements containing high doses of biotin (> 5 mg/day) may have falsely increased test results generated.

Excessive light exposure may alter Vitamin B12 and Folate values. 


Methodology:
  • Chromatography / Mass Spectrometry
Clinical Significance

Homocysteine and Methylmalonic Acid, in conjunction with Vitamin B12, may be useful for the identification of early or subclinical Vitamin B12 deficiency.


Production Schedule

Sites Performed
  • Parkview Regional Medical Center
  • Quest - Chantilly
Days Performed
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Departments
  • Chemistry
  • Sendouts - Clinical
Turn Around Time

2 to 4 days


Coding & Compliance

CPT Coding

82607 (Reflex 83090 and 83921)