Vitamin B12 Deficiency Panel, Serum

Vitamin B12 Deficiency Panel

Order Code:	VB12DEF
Epic Lab Code:	LAB4606
Order Form:	A-1a Miscellaneous Request or Epic Req

Commercial Mail-out Laboratory
01250 PFP
356-3527

Specimen(s):

Serum

Collection Medium:

	and
Red top tube	and	Red top tube

Minimum:

3 aliquots of serum are required at reference lab. One with 1.0 mL, one with 1.5 mL, one with 2.0 mL; these samples are processed in Specimen Control.

Delivery Instructions:

Deliver to laboratory within 30 minutes of collection.

Specimen Instructions:

Fasting (8 hours is suggested) Precautions: This test should not be ordered on patients who have received vitamin B12 injection within the last 2 weeks.

Testing Schedule:

Test performed Monday-Friday only at reference laboratory.

Turn Around Time:

1 day upon receipt at reference laboratory

Reference Range:

180-914 ng/L

Interpretive Data:

Vitamin B12 >400 ng/L Results do not suggest B12 deficiency-no further testing. Vitamin B12 150 ng/L to 400 ng/L Borderline vitamin B12 level- methylmalonic acid (MMA) is performed. If MMA is >0.40 nmol/L, then intrinsic factor blocking antibody (IFBA) is performed. Vitamin B12 <150 ng/L Vitamin B12 deficiency-an IFBA is performed. If IFBA is negative or indeterminate, then gastrin is performed. MMA <0.4 nmol/L This value implies that there is no vitamin B12 deficiency at the cellular level. IFBA positive Consistent with pernicious anemia, Graves disease, or Hashimoto's thyroiditis. Gastrin >200 pg/mL Result consistent with pernicious anemia. Gastrin <200 pg/mL Result does not suggest pernicious anemia.

Comments:

This mailout test requires pathologist approval for orders during inpatient encounters. Mailouts staff will not process order without approval. The pathologist covering mailouts approval can be reached at pager #5379. If approval is given, the name of the pathologist can be selected in the drop-down menu to the right of the approval warning in Epic when ordering the test.

Useful for
Diagnosis of pernicious anemia
Diagnosis of vitamin B12 deficiency-associated neuropathy

Testing Algorithm
Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.If vitamin B12 is <150 ng/L, then intrinsic factor blocking antibody (IFBA) is performed. If IFBA is negative or indeterminate, then gastrin is performed.

If vitamin B12 is 150 to 400 ng/L, then methylmalonic acid (MMA) is performed. If methylmalonic acid is >0.40 umol/L, then IFBA is performed.

Methodology:

Vitamin B12 assay - Immunoenzymatic Assay Gastrin - Automated Chemiluminescent Immunometric Assay MMA - Liquid Chromatography-Tandem Mass Spectometry (LC-MS/MS) Stable Isotope Dilution Analysis IFBA - Competitive-Binding Immunoenzymatic Assay

CPT Code:

82607-Vitamin B12 assay
82941-Gastrin (if appropriate)
83921-MMA (if appropriate)
86340-IFBA (if appropriate)