Potential mechanisms for the hypothesized link between sunshine, vitamin D, and food allergy in children

• Published in: Journal of allergy and clinical immunology Vol. 126; no. 2; pp. 217 - 222
• Main Authors: Vassallo, Milo F., Camargo, Carlos A.
• Format: Journal Article
• Language: English
• Published: United States Mosby, Inc 01.08.2010; Elsevier Limited
• Subjects: Allergens - immunology; Allergens - metabolism; Allergies; Allergy and Immunology; atopy; Child; Child, Preschool; Dietary supplements; Disease; epithelial barrier; Epithelium - immunology; Epithelium - metabolism; Epithelium - physiopathology; Female; Food; Food allergies; Food allergy; Food Hypersensitivity - epidemiology; Food Hypersensitivity - immunology; Food Hypersensitivity - metabolism; Food Hypersensitivity - physiopathology; Gastrointestinal Diseases - epidemiology; Gastrointestinal Diseases - immunology; Gastrointestinal Diseases - metabolism; Gastrointestinal Diseases - physiopathology; Human subjects; Humans; Hygiene; Hypotheses; Immune Tolerance - immunology; Immune Tolerance - radiation effects; Immunity, Mucosal - immunology; Immunity, Mucosal - radiation effects; Infections; Male; Metabolites; microbial ecology; Models, Theoretical; mucosal immunity; Obesity; Older people; Risk factors; sensitization; Sunlight; Trends; Ultraviolet Rays; Vitamin D; Vitamin D - immunology; Vitamin D - metabolism; vitamin D deficiency; Vitamin D Deficiency - epidemiology; Vitamin D Deficiency - immunology; Vitamin D Deficiency - metabolism; Vitamin D Deficiency - physiopathology; Vitamin deficiency; United States > US; UVB; Food allergy; vitamin D; Treg; atopy; microbial ecology; vitamin D deficiency; epithelial barrier; VDD; infections; 25(OH)D; sensitization; FA; mucosal immunity; T regulatory cell; Ultraviolet B solar radiation; 25-Hydroxyvitamin D
• ISSN: 0091-6749; 1097-6825; 1097-6825
• DOI: 10.1016/j.jaci.2010.06.011

Epidemiologic data suggest that the incidence of food allergy (FA) is increasing among children, yet a satisfactory model of its pathogenesis remains elusive. FA is the consequence of maladaptive immune responses to common and otherwise innocuous food antigens. Concurrent with the increase in FA is an epidemic of vitamin D deficiency (VDD) caused by several factors, especially decreased sunlight/UVB exposure. There is growing appreciation of the importance of the pleiotropic hormone vitamin D in the development of tolerance, immune system defenses, and epithelial barrier integrity. We propose a “multiple-hit” model in which VDD in a developmentally critical period increases susceptibility to colonization with abnormal intestinal microbial flora and gastrointestinal infections, contributing to abnormal intestinal barrier permeability and excess and inappropriate exposure of the immune system to dietary allergens. A compounding effect (and additional “hit”) of VDD is the promotion of a pro-sensitization immune imbalance that might compromise immunologic tolerance and contribute to FA. We propose that early correction of VDD might promote mucosal immunity, healthy microbial ecology, and allergen tolerance and thereby blunt the FA epidemic in children.