Assay

Folate

Key Words

FOL, folic acid, B12

Specimen Collection

Serum (brown) Plasma (orange)

Turnaround Time

24hrs

Test Indications

Investigation of folate deficiency may be indicated when nutritional, macrocytic or megaloblastic anaemias are suspected. A deficiency in folate has also been observed in a third of patients with psychiatric disorders, with the majority of these suffering from depression. Since a deficiency of either vitamin B12 or folate can cause megaloblastic anaemia, it is advisable to determine the concentration of both vitamin B12 and folate in order to properly diagnose the aetiology of anaemia. Hence, Vitamin B12 and Folate are reported together.

Interferences

Haemolysis invalidates the test due to RBC folate release. It is contraindicated to measure samples of patients receiving therapy with certain pharmaceuticals, (e.g. methotrexate or leucovorin), because of the cross-reactivity of folate binding protein with these compounds. Samples should be collected after a period of fasting.

Reference Range

>3.0 ug/L

Analytical Error

9.0%

Reference Change Value

71.0%

Minimum retesting interval

Requests for Vitamin B12 and Folate made within 28 days of a previous result on a patient are intervened