Folic acid is the synthetic form of folate, a water-soluble B-vitamin (Vitamin B9) essential for numerous bodily functions, particularly in DNA synthesis, repair, and methylation, and in cell division and growth.
🧬 Biological Functions
- Nucleotide synthesis (especially thymidine and purines)
- Amino acid metabolism (conversion of homocysteine to methionine)
- Red blood cell formation
- Fetal neural tube development
🍽️ Sources
- Natural Folate: Leafy greens, legumes, citrus fruits, liver
- Folic Acid (Synthetic): Fortified cereals, flour, supplements
⚠️ Deficiency Effects
| System Affected | Symptoms/Consequences |
| Hematologic | Megaloblastic anemia, fatigue, pallor |
| Neurological (in fetus) | Neural tube defects (e.g., spina bifida, anencephaly) |
| Cardiovascular | Elevated homocysteine (linked to heart disease) |
| Gastrointestinal | Glossitis, poor appetite |
🩺 Recommended Intake
- Adults: 400 mcg/day
- Pregnant women: 600 mcg/day
- Lactating women: 500 mcg/day
💊 Clinical Uses
- Prenatal supplements – to prevent neural tube defects
- Anemia treatment – especially megaloblastic anemia
- Homocysteine reduction – in cardiovascular risk management
- Adjunct therapy in methotrexate use – to mitigate side effects
🧬 Biochemical Pathways
Folic acid is converted into:
- Dihydrofolate (DHF) → then Tetrahydrofolate (THF)
- THF serves as a carrier of one-carbon units in:
- DNA synthesis (thymidylate synthase)
- Methionine regeneration from homocysteine (via methyl-THF)