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| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Folate
Test CodeFOLAC
Alias/See Also
Folic acid
Preferred Specimen
1.0 mL plasma (0.5 mL minimum)
Instructions
Protect samples from light.
Transport Container
PST (light green top). Red top and SST also acceptable
Specimen Stability
Room temperature: 8 hours, Refrigerated: 24 hours, Frozen: 7 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolyzed specimens are unacceptable.
Report Available
24 hours
Reference Range
3.1 - 17.5 ng/mL
Clinical Significance
Macrocytic anemia is the major clinical manifestation of folate deficiency. It is characterized by abnormal maturation of red blood cell precursors in the bone marrow, the presence of megaloblasts and decreased red blood cell survival. Both folate and vitamin B12 deficiency can cause macrocytic anemia. Folate supplementation can mask B12 deficiency because the associated anemia responds to folate alone. Misdiagnosis delays treatment of the deficiency allowing irreversible neurological abnormalities to progress. Appropriate treatment depends on the differential diagnosis of the deficiency.
The main causes of folate deficiency are absence of intestinal microorganisms, poor intestinal absorption (surgical resection, celiac disease), increased demands (pregnancy, liver disease, and malignancies), insufficient dietary uptake (alcoholism), anti-folate drugs (methotrexate) and anticonvulsants (carbamazepine, phenobarbital, phenytoin, valproic acid). Although serum folate measurement provides an early index of folate status, red blood cell folate more closely reflects tissue stores and is considered the most reliable indicator of folate status.
The main causes of folate deficiency are absence of intestinal microorganisms, poor intestinal absorption (surgical resection, celiac disease), increased demands (pregnancy, liver disease, and malignancies), insufficient dietary uptake (alcoholism), anti-folate drugs (methotrexate) and anticonvulsants (carbamazepine, phenobarbital, phenytoin, valproic acid). Although serum folate measurement provides an early index of folate status, red blood cell folate more closely reflects tissue stores and is considered the most reliable indicator of folate status.
