Tear and serum vitamin D levels in children with allergic rhinoconjunctivitis

Abstract Background Although solid cohort studies confirmed a preventative role for the anti-oxidant vitamin D in allergic asthma, a limited number of studies focused on allergic rhinoconjunctivitis (ARC). Here, we aimed to determine 25-hydroxycholecalciferol levels in tear and serum in young allergic rhinoconjunctivitis patients as compared to their apparently healthy matched controls. Methods In total, 22 children with allergic rhinoconjunctivitis and 31 healthy control subjects underwent serum total IgE and 25-hydroxycholecalciferol measurements. Tear levels of 25-hydroxycholecalciferol were also determined in both groups. Results The mean serum total IgE level in the ARC group (143.6 ± 132.8 IU/ml) was significantly higher than that in the control group (54.8 ± 44.1 IU/ml; p  = 0.03). Serum 25(OH)D levels were significantly higher in the ARC group (34.1 ± 12.7 ng/ml) than in the healthy controls (21.8 ± 11.3 ng/ml; p  = 0.001). Conclusions To our knowledge, this is the first reported study to show an association between serum 25-hydroxycholecalciferol and ARC in a childhood group. Higher levels of serum 25-hydroxycholecalciferol in children with allergic rhinoconjunctivitis may indicate a possible aetiopathogenic mechanism in the development of allergic rhinoconjunctivitis. This is also the first report to examine tear fluid vitamin D levels in paediatric ARC patients.