Folic Acid

Folic acid is the synthetic form of folate (vitamin B9), an essential B vitamin required for the production of red blood cells and the synthesis of DNA. It plays a critical role in cell division and growth, making it especially important during pregnancy for the development of the baby's neural tube (the structure that becomes the brain and spinal cord). Folic acid supplementation before and during early pregnancy is one of the most evidence-based and cost-effective interventions in medicine — it dramatically reduces the risk of serious birth defects. Folic acid is also used alongside iron to prevent and treat anaemia, and as a supplement for patients taking methotrexate or with conditions requiring rapid cell turnover (such as sickle cell disease and haemolytic anaemia).

• Prevention of neural tube defects (spina bifida, anencephaly) in pregnancy — ALL women who are pregnant or planning a pregnancy should take folic acid • Treatment of folate deficiency anaemia • Adjunct treatment of iron deficiency anaemia (combined iron and folic acid supplements) • Sickle cell disease — daily supplementation supports red blood cell production • Haemolytic anaemia — increased red blood cell turnover requires more folate • Prevention of folate deficiency in patients taking methotrexate or other folate antagonists • Anaemia of pregnancy — prevention and treatment • In combination with vitamin B12 for megaloblastic anaemia

• Prevention of neural tube defects: 400–800 micrograms (0.4–0.8 mg) daily, starting at least 4 weeks before conception and continuing through the first 12 weeks of pregnancy. Women at high risk (previous neural tube defect, epilepsy, diabetes, BMI >30, sickle cell disease) should take 5 mg daily — ask your doctor. • Folate deficiency anaemia: 5 mg once daily for 4 months (up to 12 months if the underlying cause persists) • Sickle cell disease: 5 mg once daily • Methotrexate patients: 5 mg once weekly (on the day after methotrexate) Folic acid is best absorbed on an empty stomach but can be taken with food. No special timing required.

Folic acid is very well tolerated and serious side effects are rare: • Nausea (mild, usually at higher doses) • Loss of appetite • Bitter taste • Sleep disturbances (rare) Important note on masking vitamin B12 deficiency: • High-dose folic acid (5 mg) can correct the blood picture of vitamin B12 deficiency anaemia while the underlying neurological damage from B12 deficiency continues undetected. It is important to check vitamin B12 levels before starting high-dose folic acid supplementation, particularly in older adults and strict vegetarians.

• Antiepileptic drugs (phenytoin, carbamazepine, phenobarbital, primidone, valproate): reduce folate absorption; conversely, folic acid can reduce blood levels of phenytoin — monitor • Methotrexate: is a folate antagonist; folic acid supplementation reduces methotrexate toxicity without reducing its therapeutic effect in rheumatoid arthritis and psoriasis (but does reduce efficacy in cancer treatment — only use as directed by oncologist) • Sulfasalazine: reduces folic acid absorption • Trimethoprim and co-trimoxazole (Septrin): folate antagonists — monitor folate levels with prolonged use, especially in pregnancy • Cholestyramine and antacids: may reduce folic acid absorption

• Store at room temperature (below 25°C) away from moisture, heat, and direct sunlight • Keep in original container with lid tightly closed • Keep out of reach of children