title: Low vitamin D levels are common in patients with epilepsy.
abstract: OBJECTIVE
  Vitamin D is important for bone health, and vitamin D deficiency may contribute to other disorders (e.g., autoimmune, infections, cancer, degenerative, diabetic, and vascular). Enzyme-inducing antiepileptic drugs have been particularly implicated for osteoporosis risk given their effects on vitamin D. We examined the prevalence of vitamin D deficiency in adult epilepsy patients.
  
  
  METHODS
  We conducted an observational study of consecutive epilepsy patients treated by two clinicians at the Emory University Epilepsy Center from 2008 to 2011 in order to determine the frequency of low vitamin D levels and possible differential antiepileptic drug risks. Vitamin D 25-OH levels were categorized as low (<20 ng/ml), borderline (20-29 ng/ml), or normal (≥30 ng/ml). Antiepileptic drugs were categorized based on their enzyme inducing properties. Descriptive and inferential statistics were employed.
  
  
  RESULTS
  Vitamin D levels were obtained on 596 patients with epilepsy. Mean age was 41 years (SD=14; range=18-81); 56% were women. Race/ethnicity was 55% Caucasian, 34% Black, 2% Asian, and 7% Unknown. The mean vitamin D level was 22.5 (SD=11.9; range = <4 to 98), and 45% had level <20 ng/ml. Mean vitamin D levels (F=6.48, p=.002) and frequencies of vitamin D categories (p=.002, Chi square test) differed across the antiepileptic drug groups. Vitamin D deficiency was present in 54% of enzyme-inducing and 37% of non-enzyme-inducing antiepileptic drugs groups.
  
  
  CONCLUSIONS
  Vitamin D deficiency is common in patients with epilepsy on antiepileptic drugs. Monitoring of vitamin D should be considered as part of the routine management of patients with epilepsy.
authors: Emory Healthcare, Atlanta, GA, United States.
authors: Diane L
authors: DL
authors: Teagarden
authors: Neurology & Neurological Sciences, Stanford University, Stanford, CA, United States. Electronic address: kmeador@stanford.edu.
authors: Kimford J
authors: KJ
authors: Meador
authors: Neurology & Pediatrics, Emory University, Atlanta, GA, United States.
authors: David W
authors: DW
authors: Loring
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000927:Anticonvulsants / Q000009:adverse effects*; D015519:Bone Density / Q000187:drug effects / Q000502:physiology*; D004827:Epilepsy / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000139:chemically induced / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D014807:Vitamin D
keywords: Antiepileptic drugs; Epilepsy; Vitamin D