Vitamin A levels in patients with CF are influenced by the inflammatory response.
BACKGROUND
Serum vitamin A, normally depressed in inflammatory conditions, is frequently low in people with CF. Vitamin A is important in respiratory epithelial regeneration and repair. We hypothesised that serum vitamin A would be associated with inflammation and disease severity.


METHODS
Serum vitamin A (as retinol), C-reactive protein (CRP), vitamin E, 25-hydroxy vitamin D (25OHD), 1,25-dihydroxy vitamin D (1,25(OH)(2)D), weight, and lumbar spine bone mineral density (LSBMD) were measured in 138 subjects with CF (5-56 years) and 138 control subjects (5-48 years). FEV(1), presence of CF liver disease (CFLD) and hospital admissions were recorded in those with CF.


RESULTS
Serum vitamin A level was lower in CF subjects than in controls (mean, 95% CI: 1.29, 1.0-1.37 vs. 1.80, 1.7-1.87 micromol/l, p < 0.0001), and inversely correlated with CRP (r(s) = -0.37, p < 0.0001). CF subjects with low vitamin A (45%) level had poorer FEV(1), weight z-score, LSBMD z-score, and higher CRP compared with those with normal levels. In the CF group CRP, vitamin E, 1,25(OH)(2)D, presence of CFLD, admissions, and age were associated with vitamin A level.


CONCLUSIONS
Serum vitamin A is negatively associated with CRP in subjects with CF, consistent with normal population studies. It is important to distinguish between low serum vitamin A associated with the inflammatory response and that due to poor nutritional stores. The role of vitamin A in CF warrants further study, in the contexts both of chronic recurrent inflammatory disease and acute pulmonary exacerbation.
Greer
Ristan M
RM
Department of Paediatrics and Child Health, University of Queensland, Brisbane, Australia. r.greer@uq.edu.au
Buntain
Helen M
HM
Lewindon
Peter J
PJ
Wainwright
Claire E
CE
Potter
Julia M
JM
Wong
Joseph C
JC
Francis
Paul W
PW
Batch
Jennifer A
JA
Bell
Scott C
SC
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000097:blood* / Q000276:immunology*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D014801:Vitamin A / Q000097:blood*
D014801:Vitamin A