ABSTRACT

Many factors contribute to the development, progression and management of allergies. Immunoglobulin E (IgE) has a well-established role in allergic disorders and vitamin D has also been implicated in some forms of allergy. Vitamin D is a fat-soluble secosteroid hormone which is actively responsible for calcium balance and bone health. It also plays important roles in regulating neuromuscular function, cellular differentiation, insulin secretion and blood pressure. IgE, produced by the B-lymphocytes, is primarily involved in mediating hypersensitivity. It is associated with anaphylaxis and other forms of allergic reactions. It also plays several other vital roles in the immune system such as functional activation of T cells and wound healing. Low serum vitamin D is associated with the onset of asthma and atopic dermatitis by triggering IgE-mediated type-1 hypersensitivity but at the same time supra-normal serum vitamin D levels are also associated with the IgE hypersensitivity in allergic conditions including psoriasis, dermatitis and rhinitis. No clear association has been established between serum IgE and vitamin D levels in IgE-mediated allergies but has been suggested to maintain normal serum vitamin D levels for potential protection against the development of IgE-mediated allergic disorders. The current review summarizes the biological roles of vitamin D and IgE, particularly in the context of allergic disorders. The currently available evidence points to altered serum vitamin D levels and disturbed vitamin D signaling as a possible reason for IgE mediated allergies but more data needs to be gathered through future studies to ascertain definitive clinical impact.