Vitamin D and bone health among people with epilepsy

Abstract

Both adults and children with epilepsy are at high risk for poor bone health, with associated osteopenia and fractures. Epilepsy has consistently been associated with low vitamin D levels, a key indicator of bone health. Many anticonvulsant medications, such as phenytoin and carbamazepine, induce hepatic CYP450 enzymes, resulting in accelerated vitamin D metabolism. This might be the mechanism by which some epilepsy treatments decrease vitamin D levels. However, even medications which result in less-potent CYP450 induction (e.g. oxcarbazepine), or inhibit hepatic enzymes (e.g. valproate), have been associated with abnormal vitamin D levels and poor bone health. Data are lacking for many of the newer anticonvulsant medications. Although vitamin D is only one among many risk factors for abnormal bone mineral density, it is a modifiable risk factor for people with epilepsy. We suggest guidelines for screening and treatment of vitamin D insufficiency for people with epilepsy.