Contribution of Selected Vitamins and Trace Elements to Immune FunctionWintergerst E.S. · Maggini S. · Hornig D.H.
Bayer Consumer Care Ltd,aBasel, and bReinach, Switzerland
Adequate intakes of vitamins and trace elements are required for the immune system to function efficiently. Micronutrient deficiency suppresses immune functions by affecting the innate T-cell-mediated immune response and adaptive antibody response, and leads to dysregulation of the balanced host response. This increases the susceptibility to infections, with increased morbidity and mortality. In turn, infections aggravate micronutrient deficiencies by reducing nutrient intake, increasing losses, and interfering with utilization by altering metabolic pathways. Insufficient intake of micronutrients occurs in people with eating disorders, in smokers (both active and passive), in individuals with chronic alcohol abuse, in patients with certain diseases, during pregnancy and lactation, and in the elderly. With aging a variety of changes are observed in the immune system, which translate into less effective innate and adaptive immune responses and increased susceptibility to infections. Antioxidant vitamins and trace elements (vitamins C, E, selenium, copper, and zinc) counteract potential damage caused by reactive oxygen species to cellular tissues and modulate immune cell function through regulation of redox-sensitive transcription factors and affect production of cytokines and prostaglandins. Adequate intake of vitamins B6, folate, B12, C, E, and of selenium, zinc, copper, and iron supports a Th1 cytokine-mediated immune response with sufficient production of proinflammatory cytokines, which maintains an effective immune response and avoids a shift to an anti-inflammatory Th2 cell-mediated immune response and an increased risk of extracellular infections. Supplementation with these micronutrients reverses the Th2 cell-mediated immune response to a proinflammatory Th1 cytokine-regulated response with enhanced innate immunity. Vitamins A and D play important roles in both cell-mediated and humoral antibody response and support a Th2-mediated anti-inflammatory cytokine profile. Vitamin A deficiency impairs both innate immunity (mucosal epithelial regeneration) and adaptive immune response to infection resulting in an impaired ability to counteract extracellular pathogens. Vitamin D deficiency is correlated with a higher susceptibility to infections due to impaired localized innate immunity and defects in antigen-specific cellular immune response. Overall, inadequate intake and status of these vitamins and minerals may lead to suppressed immunity, which predisposes to infections and aggravates malnutrition.
Dr. Silvia Maggini
Science Manager Nutritionals, Bayer Consumer Care Ltd
Peter Merian-Strasse 84
CH–4002 Basel (Switzerland)
Tel. +41 58 272 75 16, Fax +41 58 272 75 02, E-Mail firstname.lastname@example.org
Published online: August 28, 2007
Number of Print Pages : 23
Number of Figures : 1, Number of Tables : 3, Number of References : 187
Annals of Nutrition and Metabolism (Journal of Nutrition, Metabolic Diseases and Dietetics)
Vol. 51, No. 4, Year 2007 (Cover Date: September 2007)
Journal Editor: Elmadfa, I. (Vienna)
ISSN: 0250–6807 (print), 1421–9697 (Online)
For additional information: http://www.karger.com/ANM