Folic acid in erythrocytes

Folic acid in erythrocytes – this test allows for the evaluation of the body's long-term folate reserves. Unlike folic acid concentration in serum, the amount of folic acid in erythrocytes is less dependent on recently consumed food or supplements, thus better reflecting the body's supply of folates over the past few months.

Folic acid (vitamin B9) is essential for cell division, DNA and RNA synthesis, protein metabolism, and normal nervous system function. Together with vitamin B12, it is involved in the maturation of red blood cells, so its deficiency can cause megaloblastic (macrocytic) anemia. Adequate levels of folic acid are also important during pregnancy, as vitamin B9 is needed for normal fetal neural system development.

The test is used to determine and evaluate folic acid deficiency, especially when investigating macrocytic anemia, suspecting folate deficiency, inadequate absorption, or monitoring the effectiveness of prescribed treatment. Test results are always assessed alongside clinical data and other laboratory indicators, such as vitamin B12 concentration, homocysteine levels, and complete blood count.

IMPORTANT: the test is only performed together with CBC | Complete Blood Count.

Test principle: The concentration of folic acid is determined from venous blood erythrocytes using an immunochemical method. Results are presented in nanograms per milliliter (ng/ml) or nanomoles per liter (nmol/l).

Recommendations:

• Recommended when suspecting long-term folic acid deficiency.
• Useful in investigating macrocytic anemia and evaluating its causes.
• Prescribed to patients suspected of having folate absorption disorders (e.g., in celiac disease or other gastrointestinal diseases).
• Can be performed to monitor the effectiveness of folic acid treatment.
• It is recommended to arrive fasting for the test – at least 8 hours, and not to take folic acid supplements 1–2 days prior to the test unless otherwise directed by a doctor.