Vitamin D Deficiency in Ambulant Children on Carbamazepine or Sodium Valproate Monotherapy

Objective: To assess the effect of monotherapy with Carbamazepine (CBZ) and Sodium valproate (VPA) on serum 25-OH vitamin D levels in children with epilepsy compared to controls. Design: Cross-sectional study. Setting: Outpatient department of a tertiary-care Pediatric Neurology centre, and a nearby day-care centre and school. Study period: June 2012 to May 2013 Participants: Children with epilepsy aged 2 to 13 years on monotherapy with CBZ (n=28) or VPA (n=28) for at least 6 months; 109 age-matched controls from a nearby day-care centre and school. Results: The median (IQR) values of 25 (OH) vitamin D was 18.0 ng/mL (13.7-27.3), 21.35 ng/mL (16.4 -25.2) and 30.5 ng/mL (19.1-43.7) in CBZ, VPA and control group, respectively (P=0.008). 60.7% of patients in CBZ group and 35.7 % in VPA group had low 25 (OH) D levels (< 20 ng/mL) compared to 27.8% in controls (P=0.001). The serum alkaline phosphatase level was higher in children on carbamazepine therapy (P=0.001) than controls. Conclusion: This study identifies significant risk of vitamin D deficiency in ambulant children with epilepsy on monotherapy with CBZ or VPA.