Might a Supplementation of Vitamin D Be Useful in Children With Atopic Dermatitis?

Abstract

To the Editor: Numerous recent studies 1,2 show that vitamin D has additional roles in the immune system; in particular, it seems to regulate the expression of antimicrobial proteins in keratinocytes in subjects with atopic dermatitis (AD). The aim of this study was to determine the levels of vitamin D in a group of children with AD and to evaluate the relationship with clinical and laboratory findings.The study included 27 children, Caucasian, affected by mild-to-moderate AD and consecutively referred to our Pediatric Allergology Outpatients Clinic. The evaluation of the severity of AD was assessed by the SCoring Of Atopic Dermatitis (SCORAD) index. 3 SCORAD index <25 shows a mild AD (12 patients), 25-50 a moderate form (15 patients) and >50 a severe form (none).The determination of specific IgE (sIgE) was performed by ImmunoCAP (Pharmacia, Uppsala, Sweden) and sIgE concentrations >0.35 kU/L were considered as positive. A single determination of vitamin D, measured as 25 hydroxyvitamin D (25(OH)D) by means of the enzyme-linked immunosorbent assay test, was obtained from all subjects. According to the literature, 4 we considered a vitamin D Ն30 ng/mL as normal, 21-29 ng/mL as insufficient and Յ20 ng/mL as deficient.Fisher's exact test and Student's t-test were used for statistical analysis.Out of the 27 patients, 13 (48.1%) had a 25(OH)D concentration Յ20 ng/mL (group I), pinpointing a vitamin D deficiency; 8 patients (29.7%) had a value of 21-29 ng/mL (group II), considered as insufficient; and 6 children (22.2%) had a level Ն30 ng/mL (group III), considered as sufficient ( Table 1). The mean age at the time of the blood sampling was 3 years (3.5, 3.7 and 3.4 years, respectively). Out of 13 patients with deficient vitamin D levels, 11 (85%) performed the blood sampling during a lowsunlight exposure season (January-April), whereas in 50%This study was only observational and did not interfere with the clinical management of the patients, so it was not submitted to the ethical committee for approval. However, both the parents and the patients were informed that the study was proposed in an experimental manner; they were included in the study only after obtaining an informed consent.