Folic acid in pregnancy

Folate (vitamin B9) is one of thirteen vital vitamins and is found in dietary products, while folic acid is the synthetic supplement used to fortify foods with. Both are metabolically inactive and through an enzymatic process mediated by MTHFR become active. Active metabolites have a key role in the DNA methylation process. Due to genetic polymorphisms of the MTHFR gene, impairment of folate activation is common as 60% of the population are heterozygous and 25% homozygous for this. Pregnancy complications that are related to folic acid deficiency includes primarily neural tube defects, as studies suggest a 72% protective effect of folic acid supplementation. An inadequate supply of nucleotides to neuroepithelial cells and/or neural fold retardation and disturbed methylation are possible pathogenetic mechanisms. A possible link between folic acid deficiency and other pregnancy complications such as congenital heart disease, preeclampsia, intrauterine growth restriction, recurrent pregnancy loss, placental abruption, preterm labour and multiple pregnancy has been reported. Folic acid daily intake in pregnant women is 400 μg received from fortified food and vitamin supplementation to decrease risk of neural tube defects by 50%. In high risk pregnancies (previously affected) this dose is recommended for 1–3 months prior to conception.