Cellular and molecular mechanisms of vitamin D in food allergy

Abstract

Food allergies are becoming increasingly prevalent, especially in young children. Epidemiological evidence from the past decade suggests a role of vitamin D in food allergy pathogenesis. Links have been made between variations in sunlight exposure, latitude, birth season and vitamin D status with food allergy risk. Despite the heightened interest in vitamin D in food allergies, it remains unclear by which exact mechanism(s) it acts. An understanding of the roles vitamin D plays within the immune system at the cellular and genetic levels, as well as the interplay between the microbiome and vitamin D, will provide insight into the importance of the vitamin in food allergies. Here, we discuss the effect of vitamin D on immune cell maturation, differentiation and function; microbiome; genetic and epigenetic regulation (eg DNA methylation); and how these processes are implicated in food allergies.

Keywords: epigenetics; food allergy; genetics; microbiome; vitamin D.

Figure 1

Vitamin D action on target genes. Transported throughout the body unbound or bound to vitamin D‐binding protein (VDBP), vitamin D (1,25(OH)2D) enters the target cell and binds to the vitamin D receptor at the nuclear membrane. In the nucleus, this forms a heterodimer with retinoid X receptor and binds to the vitamin D response element in the promoter region of target genes. Gene expression is altered and modulatory effects take place. RXR, retinoic X receptor; VDBP, vitamin D‐binding protein; VDR, vitamin D receptor; VDRE, vitamin D response element; VitD, vitamin D