B12, Cobalamin, Folic acid, Vitamin B9, Pteroglutamic acid
24 hours
Competitive immunoassay and electrochemiluminescence immunoassay (ECLIA)
Accredited NRL Laboratory
Daily
Measuring vitamin B12 and folate/folic acid is primarily used to diagnose megaloblastic (macrocytic) anemia, evaluate unexplained peripheral neuropathy or cognitive decline, and monitor patients at high risk for malabsorption or nutritional deficiencies.
Because their metabolic pathways overlap, current guidelines generally recommend ordering serum vitamin B12 and folate assays concurrently.
Results are reported in conventional units (pg/mL and ng/mL, respectively)
Serum or Plasma
0.5 mL
Serum (SST; Gold Top or plain serum; Red Top) - Preferred Lithium Heparin Plasma with gel separator (PST; Green Top) - acceptable
High doses of Biotin (Vitamin B7) may potentially interfere with the results for this test. The effect of Biotin interference can be greatly reduced or eliminated if the sample is taken at least 8 hours following the last dose.
This test does not require any special collection or pre-analytical handling. Follow routine specimen collection protocols.
| Temperature | Period |
|---|---|
| Refrigerated | 2 days at 2-8°C |
| Frozen | 28 days at -20°C |