Learn more about folic acid - uses, side effects, and chemical composition according to the books. Folic acid tablets are used to help with pregnancy, cell growth, and blood formation. It's found in foods like spinach, beans, and nuts. Folic acid is most beneficial when taken as directed by a certified practitioner.
The use of folic acid in therapy
Folic acid is the synthetic and stable form of folate (vitamin B9), a nutrient essential for normal growth, healthy blood formation, DNA synthesis, and cell division. Textbooks like Essentials of Medical Pharmacology by K.D. Tripathi, Goodman & Gilman’s The Pharmacological Basis of Therapeutics, and standard physiology books describe folic acid as one of the most important vitamins in clinical medicine.
In therapy, folic acid is used for the prevention and treatment of megaloblastic anemia, support during pregnancy, management of certain chronic diseases, and to counter drug-induced folate deficiency. It plays a central role in metabolic pathways that support rapidly dividing cells, especially those in the bone marrow.
This detailed guide explains the complete therapeutic uses, mechanism of action, dosage, benefits, side effects, and clinical importance of folic acid, based entirely on standard medical science.
Therapeutic Uses of Folic Acid
1. Treatment and Prevention of Megaloblastic Anemia
The primary therapeutic use of folic acid is in megaloblastic anemia, a condition in which the bone marrow produces large, immature red blood cells (megaloblasts).
This happens when folate levels are low, leading to defective DNA synthesis.
Common causes include:
- Poor dietary intake
- Malabsorption
- Chronic alcoholism
- Pregnancy
- Prolonged illness
- Long-term drug therapy
Folic acid restores folate stores and allows the bone marrow to produce normal, healthy red blood cells. This effect is described in detail in pharmacology and hematology textbooks.
2. Essential Supplement During Pregnancy
Standard medical recommendations clearly state that all pregnant women and women planning pregnancy should take folic acid supplements.
This is because folate is critical for the development of the neural tube, which later forms the baby’s brain and spinal cord.
Adequate folic acid prevents neural tube defects (NTDs) such as:
- Spina bifida
- Anencephaly
Folic acid also supports:
- Normal fetal growth
- Healthy placenta formation
- Reduction of preterm birth
- Lower risk of low birth weight
This makes folic acid one of the most important prenatal supplements.
3. Supplementation for patients taking anticonvulsants for a long time
Certain antiepileptic drugs reduce folate levels in the body. Textbooks note that medicines such as
- Phenytoin
- Phenobarbitone
- Carbamazepine
interfere with folate absorption and metabolism.
Patients on these medicines are at risk of folate deficiency and megaloblastic anemia.
Folic acid supplementation helps maintain adequate levels and prevents complications without interfering with seizure control when given at appropriate doses.
4. Management of Gastrointestinal and Liver Disorders
Several chronic gastrointestinal and liver conditions reduce the absorption or storage of folate. These include:
Tropical sprue
- Celiac disease
- Inflammatory bowel disease
- Chronic liver diseases
In these conditions, the body cannot absorb sufficient folate from food.
Folic acid supplementation corrects the deficiency and restores normal hematological function.
5. Folic acid in hemolytic anemia
People suffering from chronic hemolysis, such as those with:
- Sickle cell disease
- Autoimmune hemolytic anemia
- Thalassemia minor (with increased turnover)
require higher folate levels because the bone marrow is constantly producing new red blood cells.
Folic acid supports this increased demand and prevents secondary megaloblastic changes.
6. Used With Low-Dose Methotrexate Therapy
Methotrexate, used for diseases like rheumatoid arthritis, inhibits folate metabolism.
When methotrexate is given in low doses, folic acid is added to reduce side effects such as
- Mouth ulcers
- Gastrointestinal irritation
- Liver enzyme elevation
This does not reduce the therapeutic benefit of methotrexate when used correctly.
This practice is well described in medical pharmacology books.
Mechanism of Action
Folic acid is converted in the body into tetrahydrofolate (THF), the biologically active form of folate.
THF is required for:
- Formation of DNA and RNA
- Synthesis of purines and pyrimidines
- Methylation reactions
- Formation and maturation of red blood cells
Defects in these processes lead to impaired cell division, especially in the bone marrow.
Supplementation restores normal DNA synthesis and supports healthy blood formation.
Pharmacokinetics
- Absorption: Rapidly absorbed in the small intestine
- Distribution: Widely distributed to all tissues, especially the liver
- Metabolism: Converted to active THF in the liver and other tissues
- Excretion: Excreted through urine and bile
Because the body does not store large amounts of folate, regular intake is essential.
Therapeutic Dose of Folic Acid Tablet
According to standard pharmacology references:
1. For adults
- 0.4 mg/day (for daily nutritional requirement)
- 0.4–0.8 mg/day
3. For treatment of deficiency
- 1–5 mg/day
Dose adjustment must be done by a qualified medical professional.
Side Effects of Folic Acid
Folic acid is extremely safe and is well tolerated by almost everyone.
However, high doses may cause:
- Nausea
- Bloating
- Metallic or bitter taste
- Irritability
- Sleep disturbances
Excessive doses of folic acid can mask a vitamin B12 deficiency, which can lead to serious neurological problems. Therefore, folic acid should only be taken under careful medical supervision when used in therapeutic doses.
Folate-Rich Foods (Natural Sources)
To support therapy, doctors recommend foods naturally rich in folate, such as:
- Green leafy vegetables (spinach, methi, cabbage)
- Pulses, beans, and lentils
- Whole grains
- Citrus fruits
- Tomatoes
- Nuts and seeds
- Liver and organ meats
A combination of diet and supplements helps maintain long-term folate stores.
Advantages of Folic Acid in Therapy
- Safe for long-term use
- Essential for DNA synthesis
- Protects maternal and fetal health
- Corrects anemia quickly
- Useful in chronic diseases and drug-induced deficiency
- Inexpensive and widely available
Clinical Importance in India
In India, folic acid has special significance because:
- Nutritional deficiencies are common.
- Pregnancy-related anemia is widespread.
- Many patients use long-term antiepileptic therapy.
- Chronic liver and intestinal disorders are frequently diagnosed.
Public health programs also include folic acid supplementation for pregnant women to reduce congenital malformations.