Functional effects of vitamin D: From nutrient to immunomodulator

• Published in: Critical reviews in food science and nutrition 2022, Vol.62 (11), p.3042-3062
• Main Authors: Meza-Meza, Mónica R., Ruiz-Ballesteros, Adolfo I., de la Cruz-Mosso, Ulises
• Format: Article
• Language: English
• Subjects: 25-Hydroxyvitamin D; absorption; Adipose tissue; Biological effects; Calcidiol; Calciferol; Calcitriol; Dendritic cells; Diet; Epidermis; Genomics; Immune system; Immunologic Factors - pharmacology; Immunomodulation; Immunomodulators; immunonutrient; Leukocytes (neutrophilic); Literature reviews; Lymphocytes; Lymphocytes B; Macrophages; Metabolism; Metabolites; Nutrients; Receptors; Regulatory sequences; Retinoid X Receptors; Synthesis; Ultraviolet radiation; VDR; Vitamin D; Vitamin D - metabolism; Vitamin D - pharmacology; Vitamin D receptors; Vitamin D2; Vitamin D3; Vitamins - pharmacology
• ISSN: 1040-8398; 1549-7852
• DOI: 10.1080/10408398.2020.1862753

Vitamin D can be obtained from the endogenous synthesis in the epidermis by exposure to UVB light, and from foods and supplements in the form of ergocalciferol (vitamin D 2 ) and cholecalciferol (vitamin D 3 ). The main metabolite used to measure vitamin D serum status is calcidiol [25(OH)D]. However, its active metabolite calcitriol [1α,25(OH) 2 D] performs pleiotropic effects in the cardiovascular, neurological, and adipose tissue as well as immune cells. Calcitriol exerts its effects through genomic mechanisms modulated by the nuclear vitamin D receptor (VDR)/retinoid X receptor (RXR) complex, to bind to vitamin D response elements (VDRE) in target genes of several cells such as activated T and B lymphocytes, neutrophils, macrophages, and dendritic cells; besides of its genomic mechanisms, VDR performs novel non-genomic mechanisms that involve its membrane expression and soluble form; highlighting that vitamin D could be an immunomodulatory nutrient that plays a key role during physiological and pathological events. Therefore, the aim of this comprehensive literature review was to describe the most relevant findings of vitamin D dietary sources, absorption, synthesis, metabolism, and factors that influence its serum status, signaling pathways, and biological effects of this immunonutrient in the health and disease.