Does the Vitamin D Deficiency Have Any Role in Severity or Prolongation of Seizure? A Pilot Study in Iran

Background:

Based on previous studies, vitamin D deficiency could lead to nerve stimulation. The purpose of the present study was to determine frequency and duration of seizures in children with idiopathic epilepsy in two groups; normal level of vitamin D versus decreased level of vitamin D.

Methods:

This pilot, comparative study was carried out in Zanjan University of Medical Sciences on total 40 children aging between 2 to 12 years old (23 male and 17 female) with the diagnosis of idiopathic epilepsy. All patients were receiving anti-epileptic drugs. The initial questionnaire was completed by each parent. Total 40 epileptic cases were examined in close follow-ups every three months, during total 9 months. Meanwhile, the frequency and duration of each seizure were recorded in questionnaire at every three-month period. Vitamin D blood samples were analyzed at the beginning of the study and after 9 months following the study. Serum levels of Vitamin D were analyzed by ELISA method (Elecsys2010, RocheCo, Germany; STAR FAX; 2100), simultaneously, Vitamin D level <30 ng/ml (nanogram per milliliter) was defined as Vitamin D deficiency. Cases were divided into two groups based on Vitamin D level. The frequency and duration of convulsions were compared in patients with normal level of vitamin D versus children with decreased level of vitamin D. Data were analyzed by Chi-square and t-test methods.

Results:

In all 40 patients, vitamin D level less than 30 ng/ml was detected in 32% (13 patients) at the beginning of study and 35% (14 patients) in 9 months later (13 patients were common between the two groups). There was no significant relationship between the frequency of seizures, the duration of seizures and vitamin D levels in patients. The relationship between positive family history of epilepsy and the number of seizures was reported significant. The frequency of vitamin D deficiency was higher in female cases in final evaluation.

Conclusion:

In the present study, a considerable correlation was detected between the frequency of seizures and positive history of seizure in the family. The frequency of vitamin D deficiency was higher in female cases in final analysis. No significant relationship was detected between the number of seizures, the mean duration of seizures and serum level of Vitamin D in children who received anticonvulsant drugs. However, vitamin D deficiency in patients was not overlooked in order to prevent known complications. We recommend a randomized clinical trial in the future with an adequate sample size. Moreover, a non-epileptic control group in study would be useful.