Lab Test

Folate Level

Serum Folate

Test Codes

Antrim #17239, EPIC: LAB5049, FOL

Specimen Collection Criteria

Collect: One Gold-top SST tube. (Minimum Whole Blood: 4.0 mL)
Contact Laboratory for acceptability of other tube types.

Note: Patient Preparation: Twenty-four (24) hours before this test, the patient should not take multivitamins or dietary supplements containing biotin (vitamin B7) which is commonly found in hair, skin and nail supplements and multivitamins.

Physician Office/Draw Specimen Preparation

Let SST specimens clot 30–60 minutes then immediately centrifuge to separate serum from cells. Refrigerate (2–8°C or 36–46°F) the centrifuged SST tube within two hours of collection. (Minimum: 0.5 mL)

Preparation for Courier Transport

Transport: Centrifuged SST tube, refrigerated (2–8°C or 36–46°F). (Minimum: 0.5 mL)

Rejection Criteria

Moderate to grossly hemolyzed specimens.

In-Lab Processing

Let SST specimens clot 30–60 minutes. Centrifuge SST and Microtainer® specimens to separate serum from cells. Deliver immediately to the appropriate testing station.


Specimen Stability for Testing:

Centrifuged SST tubes and Microtainers® with Separator Gel
Room Temperature (20–26°C or 68–78.8°F): 2–4 hours
Refrigerated (2–8°C or 36–46°F): 2 days
Frozen (-20°C/-4°F or below): Unacceptable

Red-top Tubes and Microtainers® without Separator Gel
Room Temperature (20–26°C or 68–78.8°F): 2–4 hours
Refrigerated (2–8°C or 36–46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room Temperature (20–26°C or 68–78.8°F): 2–4 hours
Refrigerated (2–8°C or 36–46°F): 2 days
Frozen (-20°C/-4°F or below): 7 days

Specimen Storage in Department Prior to Disposal:

Refrigerated (2–8°C or 36–46°F): 7 days


Dearborn Chemistry Laboratory
Farmington Hills Chemistry Laboratory
Grosse Pointe Chemistry Laboratory
Royal Oak Automated Chemistry Laboratory
Troy Chemistry Laboratory
Wayne Chemistry Laboratory 


Sunday – Saturday, 24 hours a day.
Results available within 24 hours after receipt in the Laboratory.

Reference Range

Normal: Greater than 5.4 ng/mL.

Test Methodology

Chemiluminescence Immunoassay.


  • Folate deficiency is commonly due to insufficient dietary intake.
  • Low serum folate concentrations may be seen in liver disease, hemolytic disorders and malignancies.
  • Folate deficiency is characteristically associated with macrocytosis and megaloblastic anemia.
  • Other conditions that cause changes in serum folate concentrations are:
Increased Folate Decreased Folate
Vegetarian diet Dilantin

Hemolysis significantly increases folate values due to the high folate concentrations in red blood cells. Methotrexate and leucovorin interfere with folate measurement because these drugs cross-react with folate binding proteins.

Clinical Utility

Both folate and vitamin B12 deficiency can cause macrocytic anemia.

Appropriate treatment depends on the differential diagnosis of the deficiency. Folate deficiency is usually due to: malnutrition, malabsorption due to disease of the proximal small bowel, increased requirement as in pregnancy and chronic hemolytic states, or acute illness. Folate deficiency may result in depression or macrocytic anemias.

CPT Codes

LOINC: 2284-8


Last Updated


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