Vitamin B12 with Reflex to Methylmalonic Acid, Serum (Vitamin B12 Status)

Casandra

Casandra Test Code AR08118Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 0055662CPT Codes 82607, 83921

Vitamin B12 with Reflex to Methylmalonic Acid, Serum (Vitamin B12 Status)

Also known as: B12 MMA

Clinical Use

Order Test

Use

This test is the preferred reflex test for evaluating vitamin B12 deficiency in individuals with macrocytic or unexplained anemia or unexplained neurologic disease. When a Vitamin B12 level is less than 300 pg/mL, Methylmalonic Acid (MMA) measurement is automatically added to help confirm vitamin B12 deficiency. Elevated MMA levels can indicate vitamin B12 deficiency, renal insufficiency, or intravascular volume contraction.

Special Instructions

Protect specimens from light during collection, storage, and shipment. Serum should be centrifuged and separated from cells within 2 hours of collection, then transferred to a transport tube and refrigerated or frozen immediately.

Limitations

EDTA plasma and room temperature specimens are unacceptable. Grossly hemolyzed or lipemic specimens are also rejected. The test has specific stability requirements: the specimen is stable for 48 hours when refrigerated, and for 1 month when frozen. There may be factors such as renal insufficiency or volume contraction that affect methylmalonic acid levels, which should be considered when interpreting results.

Test Details

New York Approved

Methodology

Immunoassay (CLIA)

Biomarkers

2 components

Vitamin B12 Status Testing • CLIAMethylmalonic Acid Testing • CLIA

LOINC Codes

Order Codes

13964-2
2132-9

Result Turnaround Time

1-5 days

Specimen

Serum

Volume

1.0 mL

Minimum Volume

0.6 mL

Container

Plain red or serum separator tube

Collection Instructions

Protect from light during collection. Centrifuge and remove serum from cells within 2 hours. Transfer to ARUP standard transport tube and refrigerate or freeze immediately.