Folic Acid

1. Introduction

Folic acid (vitamin B9) is a water-soluble vitamin essential for DNA synthesis, repair, and cell division. It plays a critical role in red blood cell formation and neural tube development in foetuses. It is widely used to prevent and treat folate deficiency and related conditions, such as anaemia and during pregnancy to prevent neural tube defects (NTDs).

2. Indications

  • Approved Indications:
    • Prevention of neural tube defects during pregnancy.
    • Treatment of folate deficiency anaemia.
    • Supplementation in malabsorption syndromes (e.g., coeliac disease, Crohn’s disease).
    • Prevention of folate deficiency in high-risk populations (e.g., those on methotrexate or anticonvulsants).
  • Off-Label Uses:
    • Adjunctive therapy in hyperhomocysteinaemia to reduce cardiovascular risk.

3. Dosage

  • Adults:
    • Folate deficiency anaemia: 5 mg once daily for 4 months or longer if deficiency persists.
    • Prevention of neural tube defects: 400 mcg daily before conception and during the first 12 weeks of pregnancy.
    • High-risk pregnancy (e.g., previous NTD-affected pregnancy, diabetes, obesity): 5 mg daily from 3 months before conception to 12 weeks of pregnancy.
  • Children:
    • Folate deficiency anaemia: 500 mcg to 1 mg daily, adjusted for age and severity.
  • Elderly:
    • No specific dose adjustment is required.

4. Administration

  • Take orally, with or without food, at the same time each day for consistency.
  • Can be combined with other multivitamins or iron supplements if prescribed.

5. Forms Available

  • Tablets: 400 mcg, 1 mg, 5 mg.
  • Liquid form: Various strengths for paediatric and special populations.

6. Side Effects

6.1. Common Side Effects

  • Nausea.
  • Bloating or abdominal discomfort.

6.2. Less Common Side Effects

  • Loss of appetite.
  • Mild rash or itching.

6.3. Rare but Serious Side Effects

  • Allergic reactions (e.g., swelling, difficulty breathing).
  • Masking of vitamin B12 deficiency (can lead to neurological complications).

7. Warnings

  • Masking B12 Deficiency: High doses of folic acid can correct anaemia caused by vitamin B12 deficiency but may worsen neurological symptoms. Monitor closely in at-risk individuals (e.g., elderly, vegans).
  • Over-supplementation: Excessive folic acid supplementation may increase the risk of certain cancers in individuals with pre-existing conditions.

8. Precautions

  • Use cautiously in patients with undiagnosed anaemia until vitamin B12 deficiency is ruled out.
  • Monitor folate levels in patients with malabsorptive conditions to ensure adequate dosing.

9. Interactions

  • Drug-Drug Interactions:
    • Methotrexate and trimethoprim: Antagonise folic acid, leading to deficiency.
    • Anticonvulsants (e.g., phenytoin): Folic acid may reduce their efficacy and increase the risk of seizures.
    • Sulfasalazine: Reduces folate absorption.
  • Drug-Food Interactions:
    • No significant interactions, but folic acid absorption is improved when taken with food.

10. Monitoring Parameters

  • Monitor haemoglobin and red blood cell indices (MCV, MCH).
  • Measure serum and red blood cell folate levels in cases of suspected deficiency.
  • Monitor for symptom improvement in anaemia (e.g., fatigue, pallor).

11. Use in Children

  • Safe and effective for preventing and treating folate deficiency in children. Doses should be adjusted based on age, weight, and severity of deficiency.

12. Use in Pregnancy

  • Category A: Essential for preventing neural tube defects and other developmental abnormalities. Recommended in all women of childbearing age planning pregnancy.

13. Use in Elderly

  • Safe for elderly patients, but consider screening for vitamin B12 deficiency before initiating high doses.

14. Use in Kidney Disease

  • No dose adjustment is typically required, but patients on dialysis may require supplementation due to increased losses.

15. Use in Liver Disease

  • Safe for use in liver disease; no dose adjustment required.

16. Patient Counselling Points

  • Take folic acid as prescribed, especially if you are planning a pregnancy or in early pregnancy.
  • Combine with a healthy diet rich in natural folate sources, such as leafy greens, citrus fruits, and legumes.
  • Inform your doctor of any other medications you are taking, particularly anticonvulsants or methotrexate.
  • Report any unusual symptoms, such as tingling or numbness, as these may indicate a vitamin B12 deficiency.
  • Do not exceed the prescribed dose without medical advice.

17. Table of Brand Names, Manufacturers, and Prices

Brand NameManufacturerPrice (USD)
FolvitePfizer$5–15 (30 tablets, 400 mcg)
Folic Acid TabletsVarious manufacturers$5–10 (30 tablets, 1 mg)
Generic Folic AcidVarious manufacturers$2–5 (30 tablets, 5 mg)

18. FAQs (15 Questions)

  1. What is folic acid used for?
    Folic acid is used to prevent neural tube defects in pregnancy, treat folate deficiency anaemia, and supplement in malabsorption conditions.
  2. How does folic acid work?
    It supports DNA synthesis, red blood cell production, and proper cell division.
  3. How long does it take for folic acid to work?
    Symptom improvement in anaemia may be seen within a few weeks, but full correction may take several months.
  4. Who needs folic acid supplementation?
    Pregnant women, individuals with folate deficiency, those on methotrexate or anticonvulsants, and people with malabsorption syndromes.
  5. Can folic acid cause side effects?
    Side effects are rare but may include nausea, bloating, or mild rash.
  6. How much folic acid is recommended during pregnancy?
    400 mcg daily for low-risk pregnancies and 5 mg daily for high-risk pregnancies.
  7. Can folic acid be taken with other vitamins?
    Yes, it is often combined with other vitamins in multivitamin formulations.
  8. Can folic acid be taken during breastfeeding?
    Yes, it is safe and supports both maternal and infant health during breastfeeding.
  9. Does folic acid interact with other medications?
    Yes, it can interact with methotrexate, anticonvulsants, and sulfasalazine.
  10. Can I take folic acid on an empty stomach?
    Yes, it can be taken with or without food.
  11. Can folic acid treat all types of anaemia?
    No, it is effective only for folate deficiency anaemia and not for anaemias caused by vitamin B12 deficiency or other factors.
  12. Is folic acid safe for children?
    Yes, it is safe and used to treat folate deficiency in children with appropriate dosing.
  13. Can folic acid prevent miscarriage?
    Folic acid may reduce the risk of certain pregnancy complications, including miscarriage, in some cases.
  14. How should folic acid be stored?
    Store at room temperature, away from moisture and heat.
  15. Can I take too much folic acid?
    Excessive doses may mask vitamin B12 deficiency and increase cancer risk in certain conditions. Stick to prescribed doses.
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