Association of antioxidants and vitamin D level with inflammation in children with atopic dermatitis.

BACKGROUND: Changing the resources of vitamin D and antioxidant nutrients may affect the course of allergic diseases. The aim of the study was to investigate the association between CoQ10, vitamin D, retinol, and α-tocopherol serum levels and severity of atopic dermatitis (AD) in children.

METHODS: Twenty-nine children with AD aged from 1 to 15 years were enrolled into the study. The severity of AD was categorized into mild or moderate (≤50 points in SCORAD - Scoring Atopic Dermatitis index) and severe (>50 SCORAD points). The control group was comprised of 22 children with negative history of allergy aged from 2 to 15. The serum measurements included vitamin D, retinol, α-tocopherol, CoQ10, C-reactive protein (CRP), complete blood count (CBC), and total immunoglobulin E (IgE).

RESULTS: Low vitamin D concentration (<20 ng/ml) was observed mainly in patients with severe AD (77.8%), compared to children with mild or moderate AD (25%) or the control group (31.8%). Concentration of retinol was decreased significantly in patients with severe AD (median 1.32 μmol/l), compared to children with mild and moderate AD (median 1.66 μmol/l), but not to the control. Among inflammatory markers, only the group with severe AD demonstrated significantly elevated platelet count (PLT), red blood cell distribution width (RDW), and eosinophil count (EO). Retinol level correlated with PLT (R = -0.7; P = 0.003), white blood count (WBC) (R = -0.54; P = 0.01), total IgE (R = -0.51; P = 0.016), mean platelet volume (MPV) (R = 0.51; P = 0.02), and also with a disease severity index, SCORAD (R = -0.55; P = 0.007), whereas vitamin D level correlated only with MPV (R = 0.61; P = 0.003). No significant changes were found in tocopherol and CoQ10 levels between groups.

CONCLUSIONS: Children with AD should be routinely tested for vitamin D deficiency, especially during disease exacerbation. Our results confirmed correlation of serum inflammatory markers with decreased concentration of vitamin A in children with AD. This finding, however, might be an effect of severe stage of disease and not only of inadequate intake of retinol in the diet.