title: Vitamin D status in pediatric irritable bowel syndrome.
abstract: OBJECTIVE
  Irritable bowel syndrome (IBS) is associated with significant morbidity in children and adolescents, and the therapeutic efficacy of available treatment options is limited. The role of vitamin D supplementation in pediatric IBS is unclear as the vitamin D status of pediatric patients with IBS is unknown. Equally, the relationship of vitamin D status with psychosomatic symptoms in children and adolescents is unclear.
  
  
  OBJECTIVE
  To characterize the vitamin D status of pediatric patients with IBS using a case-control study design.
  
  
  OBJECTIVE
  Serum 25-hydroxyvitamin D [25(OH)D] concentration will be similar between patients with IBS and controls.
  
  
  METHODS
  A retrospective case-controlled study of 116 controls (age 14.6 ± 4.3 y), female (n = 67; 58%) and 55 subjects with IBS (age 16.5 ± 3.1y), female (n = 44; 80%). Overweight was defined as BMI of ≥85th but <95th percentile, and obesity as BMI ≥95th percentile. Vitamin D deficiency was defined as 25(OH)D of <50 nmol/L, while seasons of vitamin D draw were categorized as summer, winter, spring, and fall. Major psychosomatic manifestations included in the analysis were depression, anxiety, and migraine.
  
  
  RESULTS
  More than 50% of IBS subjects had vitamin D deficiency at a cut-off point of <50 nmol/L (53% vs. 27%, p = 0.001); and >90% of IBS subjects had vitamin D deficiency at a cut-off point of <75 nmol/L (93% vs. 75%, p = 0.006). IBS subjects had significantly lower mean 25(OH)D: 53.2 ± 15.8 nmol/L vs. 65.2 ± 28.0 nmol/L, p = 0.003; and albumin: 6.2 ± 0.6 vs. 6.5 ± 0.6 μmol/L, p = 0.0.01. IBS subjects with migraine had significantly lower mean 25(OH)D concentration compared to controls (p = 0.01). BMI z-score was similar between the controls and IBS subjects (0.5 ± 1.4 vs. 1.2 ± 2.9, p = 0.11).
  
  
  CONCLUSIONS
  Pediatric patients with IBS had significantly lower 25(OH)D concentration compared to controls despite having similar mean BMI values as controls. Only 7% of the children and adolescents with IBS were vitamin D sufficient, and >50% of the subjects with IBS had vitamin D deficiency. This is a much higher prevalence of vitamin D deficiency compared to IBD and other malabsorption syndromes. Monitoring for vitamin D deficiency should be part of the routine care for patients with IBS. Randomized control trials are warranted to determine the role of adjunctive vitamin D therapy in pediatric IBS.
authors.affiliation: Division of Endocrinology, Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
authors.forename: Benjamin Udoka
authors.identifier: http://orcid.org/0000-0003-2212-0276
authors.initials: BU
authors.lastname: Nwosu
authors.affiliation: Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
authors.forename: Louise
authors.initials: L
authors.lastname: Maranda
authors.affiliation: Division of Gastroenterology, Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
authors.forename: Ninfa
authors.initials: N
authors.lastname: Candela
mesh_terms: D000293:Adolescent; D001007:Anxiety / Q000097:blood / Q000150:complications; D015992:Body Mass Index; D001835:Body Weight; D016022:Case-Control Studies; D002648:Child; D003863:Depression / Q000097:blood / Q000150:complications; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000097:blood* / Q000150:complications / Q000523:psychology; D016014:Linear Models; D008297:Male; D008881:Migraine Disorders / Q000097:blood / Q000150:complications; D015999:Multivariate Analysis; D012189:Retrospective Studies; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D055815:Young Adult
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D