title: The effect of vitamin d status on pediatric asthma at a university hospital, Thailand.
abstract: OBJECTIVE
  In the USA and Europe, hypovitaminosis D is associated with increased asthma severity, emergency department (ED) visit, and impaired pulmonary function in asthmatic patients. However, in tropical countries, data on the effect of vitamin D status on asthma is limited. This study evaluates the relationship between vitamin D status and the level of asthma control as well as other asthmatic parameters.
  
  
  METHODS
  Asthmatic children were evaluated for serum 25-hydroxyvitamin D, pulmonary function tests, a skin prick test, and the level of asthma control.
  
  
  RESULTS
  A total of 125 asthmatic children were recruited (boys, 66.4%). Their mean age±SD was 10.8±3.0 years. Vitamin D statuses were: deficiency (<20 ng/mL) in 19.2% of the patients, insufficiency (20-30 ng/mL) in 44.8%, and sufficiency (>30 ng/mL) in 36%. The vitamin D levels were 25.9±9.4 ng/mL in uncontrolled patients, 29.2±8.6 ng/mL in partly controlled patients, and 27.9±8.0 ng/mL in controlled patients (P>0.05). There were no significant differences in pulmonary function, asthma exacerbation, inhaled-corticosteroid (ICS) dose, anti-inflammatory drugs, or ED visit or hospitalization between different vitamin D statuses. Vitamin D deficiency patients were older and had a delayed onset of asthma than insufficiency or sufficiency patients. There was no significant correlation between serum vitamin D and pulmonary function/doses of ICS.
  
  
  CONCLUSIONS
  High prevalences of vitamin D deficiency and insufficiency were found in asthmatic children in Thailand; however, there was no significant relationship between vitamin D status and the level of asthma control or other asthma parameters.
authors.affiliation: Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Wijittra
authors.initials: W
authors.lastname: Krobtrakulchai
authors.forename: Jittima
authors.initials: J
authors.lastname: Praikanahok
authors.forename: Nualanong
authors.initials: N
authors.lastname: Visitsunthorn
authors.forename: Pakit
authors.initials: P
authors.lastname: Vichyanond
authors.forename: Kotchamol
authors.initials: K
authors.lastname: Manonukul
authors.forename: Busadee
authors.initials: B
authors.lastname: Pratumvinit
authors.forename: Orathai
authors.initials: O
authors.lastname: Jirapongsananuruk
keywords: 25-hydroxyvitamin D; Asthma; children; corticosteroid; vitamin D