Abstracts

Rationale: It is well known that vitamin D plays an important role in calcium metabolism. It also has been linked to several brain disorders, including cognitive decline and epilepsy. Many studies have reported the association between anticonvulsants and metabolic bone disease. We evaluated vitamin D status in children with epilepsy who are taking anticonvulsants to find the prevalence of vitamin D deficiency and risk factors for it. Methods: Serum vitamin D levels were checked in 130 children who are taking anticonvulsants from the department of Pediatrics at Dankook University Hospital. Type and duration of anticonvulsants, and blood chemistry were analyzed using their medical records. Vitamin D deficiency was defined as serum levels less than 20 ng/mL by the Endocrine Society Clinical Practice Guideline 2011. Statistical analysis was performed using SPSS for windows (version18.0, SPSS, Inc., Chicago, IL, USA) and Fisher's exact test, Kruskal-Wallis test, and Mann-Whitney U test were used in this study. Results: Sixty six were males, and sixty four were females. Their average age at study was 11.5 years. Average duration of medication was 3.77 years. Ninety three (71.5%) children had vitamin D deficiency, with average level of vitamin D 9.4 ng/mL and 4.25 years of mean duration of medications. Seven children had vitamin D less than 4 ng/mL, 47 had 4~10 ng/mL, and 39 patients had 10~20 ng/mL. Vitamin D deficiency was less common in summer and the mean values were significantly higher in summer. Serum calcium levels were significantly lower in the group with vitamin D deficiency, and the patients with vitamin D deficiency had significantly older age (142.7months vs. 128.0months, p < 0.05), and were taking the medication for a longer periods (4.25yrs vs. 2.57 yrs, p < 0.05). There were no significant differences in gender, weight and height Z-scores as well as the levels of phosphorus and alkaline phosphatase compared to those of non-vitamin D deficient children. Valproic acids, oxcarbazepine, and lamotrigine were used more frequently, and there was no significant difference in vitamin D deficiency according to the anticonvulsants. Fourteen children (10.8%) were taking more than two anticonvulsants, and all of them (100%) were vitamin D deficient. Conclusions: Vitamin D deficiency was common in children with epilepsy, especially in adolescents. It was more frequently observed in children with more than two anticonvulsants (100%). This study suggests to monitor vitamin D status regularly and also to encourage sufficient sunlight exposure and adequate exercise in children with anticonvulsants to prevent vitamin D deficiency.