Vitamin B12 w/reflex
Test Mnemonic
B12RFX
CPT Codes
- 82607 - QTY (1)
Includes
- B12
Performing Laboratory
Cleveland Clinic Laboratories
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 3 mL | Serum | SST (Gold) | Place specimen on ice after draw. | Refrigerated | Centrifuge and separate plasma/serum from cells less than one hour after collection. If collected in a non-gel separator tube, centrifuge and transfer plasma/serum to a CCL tube and refrigerate. |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 3 mL | Plasma | Lithium heparin PST (Lt. Green) | Place specimen on ice after draw. | Refrigerated | Centrifuge and separate plasma/serum from cells less than one hour after collection. If collected in a non-gel separator tube, centrifuge and transfer plasma/serum to a CCL tube and refrigerate. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | 24 hours |
| Refrigerated | 24 hours |
| Frozen | 56 days |
Days Performed
Sun - Sat
Turnaround Time
8 hours
Methodology
| Name | Description |
|---|---|
| Electro Chemiluminescence Immunoassay (ECLIA) |
Reference Range
| Vitamin B12 | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| 99 | Normal | 232-1245 | pg/mL |
Special Info
A fasting sample is preferred but not required. Patients taking a biotin dose of up to 5 mg/day should refrain from taking biotin for 4 hours prior to sample collection. Patients taking a biotin dose of 5 to 10 mg/day should refrain from taking biotin for 8 hours prior to sample collection. Patients taking a biotin dose > 10 mg/day should consult with their physician or the laboratory prior to having a sample taken. Clinicians should consider biotin interference as a source of error, when clinically suspicious of the laboratory result.
Clinical Info
Vitamin B12 (cobalamin) is important for maintaining metabolism, brain and nervous system functions, and the formation of red blood cells. Vitamin B12 is not produced by the human body, so it must be obtained through eating animal proteins such as meat, dairy, or eggs. Although the body can store sufficient vitamin B12 reserves for 2 to 5 years, deficiency can develop due to extended nutritional insufficiency among strict vegetarians, vegans, or elderly patients with limited diets. Vitamin B12 deficiency is also caused by malabsorption issues such as pernicious anemia or underlying disorders or damage to the stomach, small bowel, or pancreas. Testing for vitamin B12 is performed to detect deficiency and monitor vitamin B12 therapy. Symptoms of vitamin B12 deficiency include macrocytic megaloblastic anemia, peripheral neuropathy, glossitis, hyperreflexia, ataxia, poor coordination, deficient proprioception, affective behavioral disorder, weakness, and fatigue. Some patients may show the neurological or psychiatric defects without anemia, particularly the elderly. If vitamin B12 is greater than or equal to150 pg/mL, but less than or equal to 400 pg/mL, methylmalonic acid (MMA) and homocysteine (HOMCYS) will be performed and billed.