title: Vitamin D supplementation, the metabolic syndrome and oxidative stress in obese children.
abstract: BACKGROUND
  Previous studies suggest that vitamin D may play a role in cardiovascular and metabolic health. Oxidative stress has also been implicated in the development of cardiovascular disease. Evidence suggests that vitamin D deficiency may contribute to the occurrence of oxidative stress. This study aimed to determine whether treatment and correction of vitamin D deficiency in obese children led to changes in their metabolic profile, independent of changes in adiposity. In addition, we aimed to determine whether vitamin D deficiency and oxidative stress are causally related in obese children.
  
  
  METHODS
  In the retrospective arm, chart review identified 32 obese children who experienced normalization of vitamin D deficiency or insufficiency with vitamin D supplementation. We then correlated laboratory and anthropometric data with vitamin D levels. In the prospective arm of the study, urinary 8-isoprostane and hydrogen peroxide were measured before and after correction of vitamin D deficiency/insufficiency and correlated to vitamin D levels in seven patients.
  
  
  RESULTS
  In our predominantly Hispanic population of obese children in an urban setting, we demonstrated a cause-effect relationship between vitamin D deficiency and oxidative stress. In contrast, we found no association between vitamin D status, adiposity, and markers of insulin sensitivity, nor any effect of vitamin D treatment on the same parameters.
  
  
  CONCLUSIONS
  These discordant findings suggest a differential effect of vitamin D on cardiovascular risk factors such as oxidative stress and insulin resistance. To confirm these findings, further prospective studies with larger sample size and longer follow-up are warranted.
authors.affiliation: Department of Pediatrics, Section of Endocrinology and Diabetes, St. Christopher's Hospital for Children, Drexel University College of Medicine, Philadelphia, PA.
authors.forename: Tal
authors.initials: T
authors.lastname: Grunwald
authors.affiliation: Department of Pediatrics, Section of Endocrinology and Diabetes, St. Christopher's Hospital for Children, Drexel University College of Medicine, Philadelphia, PA.
authors.forename: Shruti
authors.initials: S
authors.lastname: Fadia
authors.affiliation: Department of Pediatrics, Section of General Pediatrics, St. Christopher's Hospital for Children, Drexel University College of Medicine, Philadelphia, PA.
authors.forename: Bruce
authors.initials: B
authors.lastname: Bernstein
authors.affiliation: Department of Pediatrics, Section of Endocrinology and Diabetes, St. Christopher's Hospital for Children, Drexel University College of Medicine, Philadelphia, PA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Naliborski
authors.affiliation: Department of Pediatrics, Section of Endocrinology and Diabetes, St. Christopher's Hospital for Children, Drexel University College of Medicine, Philadelphia, PA.
authors.forename: Shufang
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Pediatrics, Section of Endocrinology and Diabetes, St. Christopher's Hospital for Children, Drexel University College of Medicine, Philadelphia, PA.
authors.forename: Francesco De
authors.initials: F
authors.lastname: Luca
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D019587:Dietary Supplements; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000209:etiology / Q000517:prevention & control*; D009765:Obesity / Q000150:complications*; D018384:Oxidative Stress / Q000187:drug effects*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D014807:Vitamin D / Q000008:administration & dosage*; D014808:Vitamin D Deficiency / Q000209:etiology / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D014807:Vitamin D
keywords: metabolism; obesity; vitamin D