Folaattia

Folate, or folaatti in Finnish contexts, is a water-soluble B vitamin essential for one-carbon metabolism. It encompasses a group of compounds, including naturally occurring folates found in foods and the synthetic form folic acid used in supplements and fortified products. In the body, folate is converted to tetrahydrofolate (THF) and other derivatives that donate single carbon units for various metabolic processes.

Folate is crucial for DNA synthesis and repair, as well as for the methylation cycle that regulates gene expression. It supports rapid cell division and growth, making it especially important during fetal development and early infancy. Adequate folate status helps reduce the risk of neural tube defects in early pregnancy and supports overall pregnancy outcomes.

Dietary sources include leafy green vegetables, legumes, citrus fruits, and fortified grains. Natural folates in foods are typically polyglutamates that are converted during digestion, while folic acid is the more bioavailable synthetic form used in supplements and fortified foods. Absorption occurs mainly in the upper small intestine; high intakes of synthetic folic acid can lead to unmetabolized folic acid in the bloodstream in some individuals.

Deficiency can lead to megaloblastic anemia and symptoms such as fatigue, mouth ulcers, and glossitis. In pregnancy, insufficient folate is strongly associated with neural tube defects and other congenital abnormalities. Populations at risk include pregnant people, infants, individuals with malabsorption, heavy alcohol users, and those taking certain medications such as methotrexate or some anticonvulsants.

Recommended intake varies by country but is commonly around 400 micrograms of dietary folate equivalents (DFE) per day for adults, 600 micrograms DFE during pregnancy, and 500 micrograms DFE while lactating. The tolerable upper intake level for synthetic folic acid is set at about 1000 micrograms per day to minimize masking of vitamin B12 deficiency and potential adverse effects from excessive supplementation.