Folate

Keywords: Folate RBC, Red cell folate, RCF

Specimen:

5 mL blood in EDTA tube and 5 mL blood in plain tube.

Method:

Immunoassay.

Reference Interval:

Check with laboratory.

Red cell: 360-1400 nmol/L

Serum: 7-45 nmol/L.

Application:

Investigation of patients with a high MCV and/or changes in red cell morphology on blood film suggestive of Megaloblastic anaemia. Patients at risk of folate deficiency include those with chronic haemolytic anaemia, Malabsorption, pregnancy and those on certain medications (eg, anticonvulsants).

Serum folate alone is of little diagnostic value as levels may be reduced with a short term decrease in dietary intake and in systemic illness.

Interpretation:

Red cell and serum folate levels are low in Megaloblastic anaemia due to folate deficiency.

In vitamin B12 deficiency, serum folate may be normal or raised, with a normal or low red cell folate.

Low serum folate with a normal red cell folate may be seen in systemic illness and with a short term decrease in folate intake.

Reference:

Hoffman R et al. Haematology Basic Principles and Practice. 2nd ed 1995. Churchill Livingstone.