title: Iron insufficiency and hypovitaminosis D in adolescents with chronic fatigue and orthostatic intolerance.
abstract: OBJECTIVE
  More than 10% of adolescents suffer from severe fatigue and/or orthostatic intolerance. Adult studies show correlations between iron insufficiency and fatigue as well as between hypovitaminosis D and non-specific pain. We sought to determine whether there were correlations between nutritional factors (iron status, and serum vitamin D levels) and chronic ill health.
  
  
  METHODS
  We reviewed records of 188 adolescents with symptoms of fatigue and/or orthostatic intolerance and who underwent autonomic reflex screening.
  
  
  RESULTS
  Of the 188 patients, 130 patients (69%) had excessive postural tachycardia (PT) with a heart rate (HR) change of ≥30 bpm. 62 patients (47%, n = 131) had iron insufficiency with low iron stores, and 29 patients (22%, n = 131) were iron deficient. HR change did not correlate to ferritin level (P = 0.15). 21 patients (22%, n = 95) had hypovitaminosis D (25-hydroxyvitamin D ≤20 ng/mL). There was a significant association with hypovitaminosis D and orthostatic intolerance (P = 0.024).
  
  
  CONCLUSIONS
  In patients presenting with chronic fatigue and/or orthostatic intolerance, low ferritin levels and hypovitaminosis D are common, especially in patients with PT.
authors: Department of Pediatric & Adolescent Medicine, Division of General Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN 55905, USA. antiel.ryan@mayo.edu
authors: Ryan M
authors: RM
authors: Antiel
authors: Jonathan S
authors: JS
authors: Caudill
authors: Barbara E U
authors: BE
authors: Burkhardt
authors: Chad K
authors: CK
authors: Brands
authors: Philip R
authors: PR
authors: Fischer
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D015673:Fatigue Syndrome, Chronic / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D005260:Female; D005293:Ferritins / Q000097:blood; D006339:Heart Rate; D006801:Humans; D007024:Hypotension, Orthostatic / Q000150:complications; D007501:Iron / Q000097:blood*; D000090463:Iron Deficiencies; D008297:Male; D054972:Postural Orthostatic Tachycardia Syndrome / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D011187:Posture / Q000502:physiology; D012189:Retrospective Studies; D014808:Vitamin D Deficiency / Q000097:blood*
chemical_list: D005293:Ferritins; D007501:Iron