Folate (vitamin B9) deficiency

Lack of folate due to inadequate diet, chronic alcoholism, malabsorption, multiple pregnancy, prolonged methotrexate, sulfasalazine, phenytoin or trimethoprim therapy. Presents with macrocytic megaloblastic anaemia, glossitis and neuropsychiatric symptoms. Untreated in pregnancy increases neural tube defect risk.

ICD-10 E53.81 drug

Also known as: Folic acid deficiency, Vitamin B9 deficiency

Drugs used for this condition

ALevomefolate (L-methylfolate, 5-MTHF)First line · Active form of vitamin B9, ready for methylation reactionsLevomefolate is first-line for confirmed folate deficiency in patients with malabsorption, coeliac disease, long-term methotrexate, phenytoin or trimethoprim therapy and in confirmed functional MTHFR deficiency. AEMPS registers Asanvit; for suspected deficiency 0.4–1 mg/day orally is usually sufficient. In most patients without MTHFR impairment, regular folic acid is equally effective and substantially cheaper.

How to read tiers A–F

Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.

AStrong evidence – first or second line in international guidelines
BRecommended in selected cases
CStudy data contradict each other
DBenefit not proven, no documented harm
FDocumented harm, or risk without benefit