Treatment of Folic Acid Deficiency
The recommended treatment for folic acid deficiency is 1-5 mg of oral folic acid daily for a minimum of 4 months or until the cause of deficiency is corrected, with subsequent maintenance therapy of 0.4 mg daily for adults. 1, 2
Dosage and Administration
Initial Treatment
- Oral administration is preferred as most patients, even those with malabsorption, can absorb oral folic acid 2
- Dosage range: 1-5 mg daily orally 1
- Duration: Minimum of 4 months or until the cause of deficiency is corrected 1
- Parenteral administration (IM, IV, subcutaneous) at 0.1 mg/day may be necessary for patients who cannot take oral medications or those receiving parenteral nutrition 2
Special Populations
- Pregnant women: 5 mg daily during treatment phase, with maintenance at 0.4-0.8 mg daily throughout pregnancy 1, 3
- Patients with IBD on methotrexate: 5 mg once weekly 24-72 hours after methotrexate, or 1 mg daily for 5 days per week 3
- Patients on sulfasalazine: Supplementation with either folic or folinic acid (folinic acid may be more efficient) 3
- Chronic hemodialysis patients: 5 mg or more daily (non-diabetic) or 15 mg daily (diabetic) 1
Maintenance Therapy
After clinical symptoms have subsided and blood picture has normalized:
- Adults: 0.4 mg daily 1, 2
- Pregnant/lactating women: 0.8 mg daily 1, 2
- Children under 4 years: 0.3 mg daily 2
- Infants: 0.1 mg daily 2
Monitoring and Follow-up
- Repeat folate measurement within 3 months after supplementation to verify normalization 1
- Higher maintenance doses may be needed for patients with ongoing risk factors such as:
- Alcoholism
- Hemolytic anemia
- Anticonvulsant therapy
- Chronic infection 2
Important Precautions
Vitamin B12 Deficiency
- Critical safety concern: Doses greater than 0.1 mg should not be used unless vitamin B12 deficiency has been ruled out or is being adequately treated 2
- Folic acid supplementation can mask the hematological symptoms of vitamin B12 deficiency while allowing neurological damage to progress 1, 4
Maximum Dosage
- Daily doses greater than 1 mg do not enhance the hematologic effect, and excess is excreted unchanged in the urine 2
- Total daily folate consumption should generally be kept below 1 mg/day when not treating deficiency 1
Treatment Efficacy
- Folic acid is effective in treating megaloblastic anemias due to folate deficiency, as may be seen in tropical or nontropical sprue, and in anemias of nutritional origin, pregnancy, infancy, or childhood 5
- L-5-methyl-tetrahydrofolate (L-5-methyl-THF) is an alternative form that has comparable physiological activity, bioavailability, and absorption at equimolar doses to folic acid, with potential advantages including reduced risk of masking vitamin B12 deficiency 6
By following these treatment guidelines, folic acid deficiency can be effectively managed while minimizing potential risks associated with supplementation.