Evaluation of vitamin D status in children with refractory epilepsy

Objective: Vitamin D deficiency has been reported in children using antiepileptic drugs. Multiple antiepileptic drugs may conceivably increase the risk of vitamin D deficiency. The aim of this study is to determine vitamin D status and risk factors for vitamin D deficiency in children with refractory epilepsy. Methods: Forty children with refractory epilepsy evaluated in our tertiary pediatric neurology outpatient clinic were included in the study, and serum 25-hydroxy vitamin D, parathyroid hormone, calcium, phosphate and alkaline phosphatase levels were assessedd. Vitamin D deficiency was defined as 25-hydroxy vitamin D levels < 20 ng/mL, and insufficiency between 21 and 29 ng/mL. Correlations between vitamin D levels and type of epilepsy (generalized or localized), etiology of epilepsy (symptomatic vs idiopathic), body mass index, frequency of seizures, number, and type (old or new; enzyme inducing or not) of antiepileptic drugs, presence of intellectual disability, ambulatory status and gross motor function classification scores were evaluated. Results: The study group consisted of 17 boys and 23 girls with a mean age of 6.65 +/- 5.29 years. Vitamin D deficiency was identified in 25 (62.5%) and insufficiency in 6 (15%) the patients. There was no correlation between vitamin D levels and type of epilepsy, etiology of epilepsy, body mass index, seizure frequency, number of antiepileptic drugs, type of antiepileptic drugs, presence of intellectual disability, ambulatory status and gross motor function classification scores. Conclusion: We found that vitamin D deficiency was increased in this cohort of children with refractory epilepsy. Vitamin D level should be monitored in patients with refractory epilepsy irrespective of the potential risk factors.