Folate deficiency can occur for several reasons, including:[1][2][3][4]
- Insufficient dietary intake
- Certain medications (e.g., methotrexate, antiepileptics, oral contraceptives)
- Impaired absorption (e.g., celiac disease, gastric bypass, alcohol use disorder)
- Pregnancy (due to an increased biological demand for folate)
- Genetic polymorphisms (e.g., MTHFR, DHFR)
A folate deficiency can be diagnosed by doing a blood test, as the primary clinical sign is a type of anemia characterized by abnormally large and underdeveloped red blood cells (megaloblastic anemia).[4] Symptoms of deficiency can include fatigue, poor concentration, increased heart rate (tachycardia), irritability, dizziness, pale skin, and a painful red tongue.[2]