title: Vitamin A deficiency alters airway resistance in children with acute upper respiratory infection.
abstract: OBJECTIVE
  To assess whether vitamin A deficiency alters the recovery of total respiratory resistance (TRR) following acute upper respiratory tract infection (URI).
  
  
  METHODS
  This is a case control study of children, age 4-6 years and grouped as: URI, (n = 74), URI and wheezing, (URI-wheezing, n = 52), and healthy controls (n = 51). Vitamin A and total respiratory resistance (TRR) were assessed using the modified relative dose response (MRDR) and forced oscillometry, respectively.
  
  
  RESULTS
  Children with URI and URI-wheezing had lower retinol, 32.4 ± 13.12 and 18.3 ± 6.83 µg/dl respectively, compared to controls, 56.9 ± 29.82 µg/dl (ANOVA, P < 0.001). The MRDR was elevated in children in the URI or URI-wheezing groups 0.066 ± 0.045 and 0.021 ± 0.021, respectively, compared to controls 0.007 ± 0.006 (ANOVA, P < 0.0001). The TRR in the URI and URI-wheezing groups differed from controls. During convalescence, the TRR failed to decline in the URI-group only when the MRDR was >0.06. In the URI-wheezing group, TRR declined independently of retinol and MRDR.
  
  
  CONCLUSIONS
  Vitamin A contributes to preservation of airway function during and in recovery after upper respiratory infection in children.
authors: Heriberto Bezerra Pediatric Hospital, Universidade Federal do Rio Grande do Norte, Natal, Brazil.
authors: Cleia T
authors: CT
authors: Amaral
authors: Núbia N
authors: NN
authors: Pontes
authors: Bruna L L
authors: BL
authors: Maciel
authors: Hugo S M
authors: HS
authors: Bezerra
authors: Ana Nataly A B
authors: AN
authors: Triesta
authors: Selma M B
authors: SM
authors: Jeronimo
authors: Stephen E
authors: SE
authors: McGowan
authors: Vera M
authors: VM
authors: Dantas
mesh_terms: D000403:Airway Resistance; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D012135:Respiratory Sounds / Q000503:physiopathology; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000503:physiopathology*; D014801:Vitamin A / Q000032:analysis; D014802:Vitamin A Deficiency / Q000453:epidemiology* / Q000503:physiopathology*
chemical_list: D014801:Vitamin A; D002097:C-Reactive Protein