Abstract
Immune support by micronutrients is historically based on vitamin C deficiency and supplementation in scurvy in early times. It has since been established that the complex, integrated immune system needs multiple specific micronutrients, including vitamins A, D, C, E, B6, and B12, folate, zinc, iron, copper, and selenium, which play vital, often synergistic roles at every stage of the immune response. Adequate amounts are essential to ensure the proper function of physical barriers and immune cells; however, daily micronutrient intakes necessary to support immune function may be higher than current recommended dietary allowances. Certain populations have inadequate dietary micronutrient intakes, and situations with increased requirements (e.g., infection, stress, and pollution) further decrease stores within the body. Several micronutrients may be deficient, and even marginal deficiency may impair immunity. Although contradictory data exist, available evidence indicates that supplementation with multiple micronutrients with immune-supporting roles may modulate immune function and reduce the risk of infection. Micronutrients with the strongest evidence for immune support are vitamins C and D and zinc. Better design of human clinical studies addressing dosage and combinations of micronutrients in different populations are required to substantiate the benefits of micronutrient supplementation against infection.
Highlights
From the moment of birth, our bodies are bombarded by pathogens whose sole purpose is to live and replicate in a warm, moist, nutrient-rich environment
This review provides an overview of the known mechanisms of micronutrients that are fundamental to immune function and outlines the effects of inadequate dietary intakes on the risk of infection
T cells ignore complexes that come from a self-antigen but trigger an immune response if the antigen fragment comes from a foreign protein–a process accompanied by a second signal, such as the presence of IL-2
Summary
From the moment of birth, our bodies are bombarded by pathogens whose sole purpose is to live and replicate in a warm, moist, nutrient-rich environment. Homing of T cells to the skin [61]; calcitriol inhibits T-cell proliferation [7]; inhibitory effects mainly in adaptive immunity (e.g., Th1-cell activity) [7]; stimulatory effects in innate immunity [7]; inhibits the effector functions of T helper cells and cytotoxic T cells [27,62], but promotes the production of Tregs [27,62,63]; inhibitory effect on the differentiation and maturation of the antigen-presenting DCs, and helps program DCs for tolerance [27,64,65,66]. Induces proliferation of cytotoxic T cells [67]; involved in Th1 cytokine production and supports Th1 response [3]; essential for intracellular binding of tyrosine kinase to T cell receptors, required for T cell development, differentiation, and activation [49]; induces development of Treg cells and is important in maintaining immune tolerance [27,54,55]. APC, antigen-presenting cell; DC, dendritic cells; IFN, interferon; IL, interleukin; MHC, major histocompatibility complex; NK, natural killer; PGE2, prostaglandin E2; RNS, reaction nitrogen species; ROS, reactive oxygen species; Th, helper T cell; TGF, transforming growth factor; TNF, tumor-necrosis factor; Tregs, regulatory T cells
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
