title: Vitamin D Levels in Children with Adenotonsillar Hypertrophy and Otitis Media with Effusion.
abstract: BACKGROUND
  Vitamin D has been suggested to play a considerable role in the function of the immune system in various infectious, inflammatory, and autoimmune conditions. Otitis media with effusion (OME), defined as the presence of non-purulent fluid within the middle ear without signs or symptoms of suppurative otitis media, has a number of inflammatory predisposing factors. This study was designed to explore the association between vitamin D deficiency and OME.
  
  
  METHODS
  In this cross-sectional study, 74 children aged 2-7 years with an obstructive indication for adenotonsillectomy were included. Patients were divided into two groups based on the need for ventilation tube insertion for OME. Thirty-two children were enrolled in the OME group and 42 in the control group. The mean vitamin D level was compared between the two groups.
  
  
  RESULTS
  Mean vitamin D concentration in all patients was 11.96±5.85 ng/ml (9.79±4.36 ng/ml in the OME group and 13.61±6.33 ng/ml in the control group; P=0.003). There was also a significant difference in levels of vitamin D in patients referred in winter (9.0±2.94 ng/ml) compared with the summer (19.85±4.21 ng/ml; P=0.001). Data analyzed based on the season in which the patients were referred showed no significant difference between the OME and the control group.
  
  
  CONCLUSIONS
  Although our results showed lower serum levels of vitamin D in OME patients, the difference was not significant when seasons were taken into consideration. Therefore, the season is an important confounding factor in any research related to vitamin D due to the effect of sun-induced vitamin D.
authors.affiliation: Skull Base Research Center, ENT and Head & Neck Research Center, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Alimohamad
authors.initials: A
authors.lastname: Asghari
authors.affiliation: ENT and Head & Neck Research Center, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Bagheri
authors.affiliation: ENT and Head & Neck Research Center, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Jalessi
authors.affiliation: ENT and Head & Neck Research Center, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Mahdi
authors.initials: MM
authors.lastname: Salem
authors.affiliation: ENT and Head & Neck Research Center, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Elahe
authors.initials: E
authors.lastname: Amini
authors.affiliation: ENT and Head & Neck Research Center, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Sahand
authors.initials: S
authors.lastname: GhalehBaghi
authors.affiliation: ENT and Head & Neck Research Center, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Bakhti
keywords: Adenoids; Child; Otitis Media; Seasons; Vitamin D