Optimum dose of oral folic acid supplementation in transfusion-dependent thalassemia: a randomized controlled trial.

AIM AND

OBJECTIVES

We compared the effect of different doses of oral folic acid (FA) supplementation (5 mg/day vs. 2.5 mg/day vs. 5 mg/week) on the proportion of children with folate excess (serum folate >20 ng/ml) and plasma homocysteine (Hcys) excess (>15 µmol/l) in transfusion-dependent thalassemia (TDT).

MATERIALS AND

METHODS

Children with TDT aged 5-18 years received oral FA in doses of 5 mg/day (Group 1), 2.5 mg/day (Group 2) and 5 mg/week (Group 3) for 9 months, after a wash-off period of 8 weeks. Folate levels (Serum and RBC) and plasma Hcys levels were measured after the therapy.

RESULTS

Ninety children were randomized to receive one of the three interventions (30 per group). After wash-off period, the median serum folate levels were significantly lower and five children developed folate deficiency; the median [interquartile range (IQR)] serum folate levels (ng/dl) were comparable in the three groups [Group 1: 6.5 (3.3-14.2), Group 2: 5.1 (2.6-10.5) and Group 3: 4.8 (3.4-10.0)]. After 9 months of intervention, the median (IQR) serum folate levels (ng/ml) were comparable in all participants [Group 1: 18.0 (6.5-28), Group 2: 13.5 (6.4-24.5) and Group 3: 9.7 (5.3-22.5); p = 0.11]. Proportion of children with serum folate excess was 40%, 26.7% and 26.7% in Group 1, Group 2 and Group 3 (p = 0.48). Proportion of children with RBC folate excess was 92%, 86.7% and 86.7% in Group 1, Group 2 and Group 3 (p = 0.79). Hyperhomocysteinemia was seen in eight children with no significant difference between median Hcys levels in the groups (p = 0.75).

CONCLUSION

Folic acid supplementation is recommended in TDT with 5 mg weekly dose being adequate.