Folic Acid

Folic Acid

Other names: Folate, vitamin B9.

Description:

Folate is a water-soluble vitamin which plays an essential role in DNA synthesis.

Mechanism of action:

Participates in transfer/methylation reactions which are important in synthesizing nitrogenous bases in DNA and RNA. This is an essential process in the maturation of red blood cells [1].

It has been proposed that folate prevents neural tube defects through its complex relationship with ubiquitination and expression of neural tube closure-related genes [1].

Folate functions as an important regulator of homocysteine, with its consumption inversely related to homocysteine blood concentration.

Common indications/uses:

Neural tube defect prevention

Macrocytic and megaloblastic anemia due to folate deficiency

Vitiligo treatment

Cognitive performance

Prevention of folic acid deficiency in hemodialysis (HD) patients

Stroke prevention

Dosing:

Neural tube defect prevention: 0.4–0.5 mg daily beginning 5–6 months before conception

Macrocytic anemia: 1–5 mg daily

Prevention of folic acid deficiency in HD dependence: 1–5 mg daily

Evidence:

The US preventive service task force recommends periconceptional folic acid supplementation for the prevention of neural tube defects. It has a grade A recommendation, the highest recommendation grading based on reviewed evidence.

Randomized controlled trials have documented that dietary supplementation of folic acid reduces blood levels of homocysteine. Since 1969, there has been substantial evidence linking homocysteine plasma and risk of cardiovascular disease via its impact on the atherosclerotic process.

The Hope 2 study revealed folic acid supplementation reduced risk of stroke by 24%. While a meta-analysis indicated that folic acid supplementation can significantly reduce the risk of stroke in individuals without a history of stroke, and thus should be considered for primary prevention.

Folic acid and its role in improving cognitive function remains unclear, but it may improve cognitive function by reducing levels of homocysteine.

Folic acid may also have a therapeutic role in the treatment of Vitiligo via its effect on homocysteine.

Safety concerns:

Folic acid is generally considered a safe and non-toxic supplement. There is debate whether it is associated with an increased cancer risk.

Adverse reactions:

Increased seizure risk through its interaction with antiepileptic medications.

Drug interactions:

Interacts with the metabolism of antiepileptic drugs such as phenytoin, carbamazepine, and phenobarbital, reducing serum levels, and increasing the likelihood of seizure.

In addition, folic acid interacts with anti-folate drugs such as the chemotherapy and autoimmune agent methotrexate. Folate may render these drugs less effective.