Folic acid (folate) is a water‑soluble B‑vitamin essential for DNA synthesis, cell division, and red blood cell formation.

Deficiency can lead to megaloblastic anemia and complications in pregnancy.

Clinical uses include:

Diagnosing folate deficiency anemia.

Monitoring patients with malnutrition, malabsorption syndromes, or chronic alcoholism.

Assessing nutritional status in pregnancy (folate deficiency increases risk of neural tube defects).

Evaluating patients with unexplained anemia or neurological symptoms.

Often measured alongside Vitamin B12 to differentiate causes of anemia.

Analyte: Serum folate (Vitamin B9) concentration.

Normal Range (varies by lab): ~2–20 ng/mL.

Abnormal Findings:

Low folate: Suggests nutritional deficiency, malabsorption (celiac disease, Crohn’s), chronic alcoholism, or increased demand (pregnancy).

High folate: May occur with supplementation or rarely in certain metabolic disorders.

Clinical Use:

Provides a direct measure of folate status.

Helps guide treatment of megaloblastic anemia.

Supports prenatal care and prevention of neural tube defects.