[Role of vitamin D in allergic diseases: Current research status]

Recent research has focused on the relationship between vitamin D and allergy development. Results show that on the one hand a vitamin D deficiency can be responsible for the emergence of allergies, however, on the other hand a vitamin-D (over-) substitution was also seen in context with an increased allergy development.

This article provides an overview on the current state of research and points at the problematic aspects that accompany the assessment of these studies.

The paradoxic effect of vitamin D is currently being explained by epigenetic programming in pregnancy, by too low vitamin-D levels or excessive supplementation in newborns. Very recently, a gender-specific impact of vitamin D is also being discussed.

For a final assessment of vitamin-D effects on the emergence of allergies, further research is necessary. Due to a high level of heterogeneity among current observational studies regarding central aspects of the discussion, randomised clinical trials are recommended.