Dose-response association between vitamin D deficiency and atopic dermatitis in children, and effect modification by gender: a case-control study.

In this case-control study in children, we found a statistically significant dose-response association between vitamin D deficiency and AD. We also observed a statistically significant effect modification of this association by gender. Further research is recommended to study this association longitudinally, and to examine whether treating vitamin D deficiency may potentially improve AD. Key points Question: Can atopic dermatitis be associated with vitamin D deficiency? Finding: Serum 25(OH)D levels were significantly lower in cases with AD than in controls. Prevalence ratios for comparing male participants with intermediate and deficient vitamin D levels to those with optimal levels were 3.38 (1.21, 9.40) and 5.20 (1.91, 14.13), respectively, whereas in the female participants were 1.32 (0.96, 1.83) and 1.49 (1.04, 2.14), respectively (p-interaction <.001). Meaning: vitamin D deficiency is associated with AD in children, effect modification of this association by gender was also observed.