Vitamin D Levels in Children and Adolescents with Antiepileptic Drug Treatment

PURPOSE This study was to evaluate the relationship of 25(OH)D3 levels with anticonvulsant use and other possible factors in epileptic children and adolescents. MATERIALS AND METHODS We studied 143 patients with epilepsy (90 boys, 53 girls; 11.21±4.49 years), who had been treated with anticonvulsants for more than 1 year. Patients who had taken multiple vitamins before the blood test and those who have the limitation of physical activity (wheelchair-bound) were excluded from the study. We evaluated the difference in vitamin D status according to the type and number of anticonvulsants taken and other factors such as gender, age, intelligence and seizure variables. RESULTS For patients with mental retardation or developmental delay, 25(OH)D3 levels were lower than the levels in patients with normal intelligence quotient levels (p=0.03). 25(OH)D3 levels were lower in patients who had taken anticonvulsants for more than 2 years as compared to those who had taken them for less than 2 years (p=0.03). Those taking oxcarbazepine had significantly lower vitamin D levels than patients taking valproic acid (p=0.01). However, no effects of number of anticonvulsants taken were detectable. More than two-thirds of the patients were diagnosed with osteopenia or osteoporosis in patients showing either vitamin D insufficiency or deficiency. CONCLUSION The possibility of vitamin D deficiency can be considered in pediatric patients taking anticonvulsants if they have mental retardation or developmental delay or if they have been taking anticonvulsants for more than 2 years or taking hepatic enzyme inducing drugs.