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23019 Vitamin B12

Vitamin B12
Test Code: B-12
Synonyms/Keywords
Vitamin B-12, B12, Cyanocobalamin​
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
No​ Serum​ Serum Separator Tube (SST) ​Red Top Tube (RTT)​ 0.5 mL​ 0.4 mL​ 0.3 mL​
Collection Processing Instructions
​Refrigerate off the cells up to 4 hours. If analysis will be delayed longer than 4 hours, freeze the sample. Avoid repeated freezing and thawing of serum specimen.
Specimen Stability Information
Specimen Type Temperature Time
Serum​ Refrigerated off cells​ <4 hours​
Frozen​ >4 hours​
Rejection Criteria
Moderately hemolyzed
Interference
​For testing performed at The Diagnostic & Treatment Center lab (Weston Center): High doses of exogenous biotin (also termed Vitamin B7, Vitamin H or Coenzyme R) may interfere with this assay. It is recommended that patients refrain from consuming any multivitamin or supplement containing biotin for at least 72 hours prior to collection of a blood sample.
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Diagnostic Treatment Center​ ​Monday through Sunday​​Less than 2 hours​ ​Homogeneous Sandwich Chemiluminescent Immunoassay/Siemens Dimension Vista
Marshfield​ Monday through Sunday​Less than 2 hours​ Competitive Immunoassay using Direct Chemiluminescent Technology/Siemens Centaur ​
Reference Range Information
Performing Location Reference Range
All Performing Sites 160 - 1000 pg/mL​
Interpretation

​For normal values:  B12 immunoassays may rarely be falsely normal in patients with deficiency.  If the clinical suspicion remains high (e.g. unexplained significant macrocytic anemia), consider ordering serum methymalonic acid).

For low values:  B12 immunoassays have suboptimal diagnostic specificity.  Although a trial of B12 supplementation may be reasonable, confirmatory testing with serum methylmalonic acid is recommended.  Keep in mind that modest elevations in MMA are common with even mild renal insufficiency and in older adults due to decreased renal clearance.  True deficiency usually has very high MMA values.


Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
82607 ​ ​ ​ ​ ​
Synonyms/Keywords
Vitamin B-12, B12, Cyanocobalamin​
Ordering Applications
Ordering Application Description
​Centricity

​a. B-12, Vitamin

b. Vit B-12

​Cerner ​Vitamin B-12
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
No​ Serum​ Serum Separator Tube (SST) ​Red Top Tube (RTT)​ 0.5 mL​ 0.4 mL​ 0.3 mL​
Collection Processing
​Refrigerate off the cells up to 4 hours. If analysis will be delayed longer than 4 hours, freeze the sample. Avoid repeated freezing and thawing of serum specimen.
Specimen Stability Information
Specimen Type Temperature Time
Serum​ Refrigerated off cells​ <4 hours​
Frozen​ >4 hours​
Rejection Criteria
Moderately hemolyzed
Interference
​For testing performed at The Diagnostic & Treatment Center lab (Weston Center): High doses of exogenous biotin (also termed Vitamin B7, Vitamin H or Coenzyme R) may interfere with this assay. It is recommended that patients refrain from consuming any multivitamin or supplement containing biotin for at least 72 hours prior to collection of a blood sample.
Reference Range Information
Performing Location Reference Range
All Performing Sites 160 - 1000 pg/mL​
Interpretation

​For normal values:  B12 immunoassays may rarely be falsely normal in patients with deficiency.  If the clinical suspicion remains high (e.g. unexplained significant macrocytic anemia), consider ordering serum methymalonic acid).

For low values:  B12 immunoassays have suboptimal diagnostic specificity.  Although a trial of B12 supplementation may be reasonable, confirmatory testing with serum methylmalonic acid is recommended.  Keep in mind that modest elevations in MMA are common with even mild renal insufficiency and in older adults due to decreased renal clearance.  True deficiency usually has very high MMA values.


For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Diagnostic Treatment Center​ ​Monday through Sunday​​Less than 2 hours​ ​Homogeneous Sandwich Chemiluminescent Immunoassay/Siemens Dimension Vista
Marshfield​ Monday through Sunday​Less than 2 hours​ Competitive Immunoassay using Direct Chemiluminescent Technology/Siemens Centaur ​
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
82607 ​ ​ ​ ​ ​
For most current information refer to the Marshfield Laboratory online reference manual.