Immunomodulatory Properties of Vitamin D in the Intestinal and Respiratory Systems

• Published in: Nutrients Vol. 15; no. 7; p. 1696
• Main Authors: Hamza, Fatheia N, Daher, Sarah, Fakhoury, Hana M A, Grant, William B, Kvietys, Peter R, Al-Kattan, Khaled
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30.03.2023; MDPI
• Subjects: acute respiratory distress syndrome (ARDS); Alfacalcidol; Antiinfectives and antibacterials; Antimicrobial peptides; Calcifediol; Calciferol; Cardiopulmonary system; Coronaviruses; COVID-19; Drug dosages; Dysbacteriosis; Enzymes; Gastrointestinal system; Health aspects; Homeostasis; Humans; Immune response; Immune system; Immunity, Innate; Immunomodulation; Immunomodulators; Infections; Inflammatory bowel disease; inflammatory bowel disease (IBD); Inflammatory Bowel Diseases; Innate immunity; Intestine; Intestines; Intracellular signalling; Lungs; Microbiota; Microorganisms; Peptides; Physiological aspects; Receptors, Calcitriol; Respiratory distress syndrome; Respiratory organs; Respiratory System; Review; Signal transduction; VDR signaling; Vitamin D; Vitamin D - physiology; Vitamin D receptors; Vitamin deficiency; Vitamins; Saudi Arabia; VDR signaling; epithelial barrier; innate immunity; vitamin D; toll-like receptor (TLR); inflammatory bowel disease (IBD); acute respiratory distress syndrome (ARDS); antimicrobial peptides
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu15071696

Vitamin D plays a crucial role in modulating the innate immune response by interacting with its intracellular receptor, VDR. In this review, we address vitamin D/VDR signaling and how it contributes to the regulation of intestinal and respiratory microbiota. We additionally review some components of the innate immune system, such as the barrier function of the pulmonary and intestinal epithelial membranes and secretion of mucus, with their respective modulation by vitamin D. We also explore the mechanisms by which this vitamin D/VDR signaling mounts an antimicrobial response through the transduction of microbial signals and the production of antimicrobial peptides that constitute one of the body's first lines of defense against pathogens. Additionally, we highlight the role of vitamin D in clinical diseases, namely inflammatory bowel disease and acute respiratory distress syndrome, where excessive inflammatory responses and dysbiosis are hallmarks. Increasing evidence suggests that vitamin D supplementation may have potentially beneficial effects on those diseases.