Background: Epilepsy has a wide-ranging impact on the quality of life in patients of all age groups. Reduced levels of active vitamin D contribute to various bone diseases and may influence seizure control. Nevertheless, the risk factors for low vitamin D levels in patients with epilepsy remain inconclusive and are not well-established. The limited number of studies in Thailand may not be sufficient to provide guideline recommendations for screening vitamin D levels in adults with epilepsy.

Objective: To evaluate the prevalence and risk factors of low vitamin D levels in Thai adults with epilepsy taking long-term antiepileptic drugs. To provide supporting recommendations for screening vitamin D levels in patients with epilepsy for early diagnosis and appropriate vitamin supplementation.

Materials and Methods: The present study was a cross-sectional study conducted on 87 adults with epilepsy aged 18 to 76 years who were followed up at the Neurological Institute of Thailand between March and October 2023. Patients with comorbidities affecting vitamin D metabolism were excluded from the study. Baseline demographic data, epilepsy-related information, and anti-seizure medication information were analyzed. Blood tests for vitamin D for 25-hydroxyvitamin D [25(OH)D], calcium, phosphorus, and albumin were performed.

Results: The prevalence of low vitamin D levels was 85%, including deficiency at 37% and insufficiency at 48%, with the mean (±SD) of serum 25(OH)D being 21.9±7.60 ng/mL. Multivariate analyses revealed that female was significantly associated with low vitamin D levels, adjusted OR 4.97 (95% CI 1.23 to 20.05). There was no significant association among epilepsy-related information, anti-seizure medications, and low vitamin D levels.

Conclusion: The prevalence of low vitamin D levels in the present study was significantly higher than that observed in the previous studies, which is consistent with the findings of the recent studies in many countries. The authors strongly recommend screening for vitamin D levels in Thai adults with epilepsy, particularly in females. Early diagnosis and management of this condition are beneficial for patients with epilepsy and can help mitigate the various complications resulting from low vitamin D levels.

Received 25 January 2024 | Revised 29 February 2024 | Accepted 4 March 2024

DOI: 10.35755/jmedassocthai.2024.4.13961