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1
st
International Immunonutrition Workshop, Valencia, 3–5 October 2007, Valencia, Spain
Contribution of selected vitamins and trace elements to immune function
S. Maggini
1
, E. S. Wintergerst
2
, S. Beveridge
1
and D. Hornig
3
1
Bayer Consumer Care, Basel, Switzerland,
2
Bayer Diabetes Care, Basel, Switzerland and
3
Bayer Diabetes Care,
Reinach, Switzerland
The immune system requires essential nutrients to function efficiently. Inadequate intake and status of vitamins and trace elements may
lead to suppressed immunity, which predisposes to infections and aggravates undernutrition. Available data indicate a role for vitamins A,
B
6
,B
12
, C, D and E and folate and for the trace elements Se, Zn, Cu and Fe in the immune response. Evidence has accumulated that in
human subjects these nutrients selectively influence the immune response, induce dysregulation of a coordinated host response to infec-
tions in the case of deficiency and oversupply, and that deficiency may impact on the virulence of otherwise harmless pathogens. Thus,
micronutrients are required at appropriate intakes for the immune system to function optimally and contribute to the body’s natural
defences on three levels by supporting the physical barriers (skin and mucosa), cellular and humoral immunity. Vitamins A, C and E and
the trace element Zn assist in enhancing the skin barrier function. The vitamins A, B
6
,B
12
, C, D and E and folic acid and the trace
elements Fe, Zn, Cu and Se work in synergy to support the protective activities of immune cells. Finally, all these micronutrients, except
vitamin C and Fe, are essential for antibody production.
The table summarises the most important roles of selected vitamins and trace elements in immune function
(1–3)
.
Micronutrient Main roles in the immune system
Vitamin A Normal differentiation of epithelial tissue and gene expression
Important role both in humoral antibody response and cell-mediated immunity
Deficiency impairs innate immunity, induces inflammation, potentiates existing inflammatory conditions and impairs ability
to defend against extracellular pathogens
Supplementation is of benefit in reducing the morbidity and mortality from infectious diseases (especially children)
Vitamin D Potent immune system modulator when metabolized to 1,25-dihydroxycholecalciferol, is involved in cell proliferation and enhances
innate immunity by increasing the differentiation of monocytes to macrophages
Deficiency correlates with higher susceptibility to infections as a result of impaired localized innate immunity and defects in antigen
specific cellular immune response
Supplementation together with a high-Ca diet inhibits progression of autoimmune disorders
Vitamin E Optimizes and enhances immune response (T-helper (Th) 1 response)
Supplementation in healthy adults increases T-cell proliferation, improves the CD4 + :CD8 + , and decreases indices of oxidative stress
Supplementation of elderly individuals improves overall immune function
Vitamins B
6
and B
12
and folic acid
Interfere with immune function through involvement in nucleic acid and protein biosynthesis
Maintain Th1 immune response (vitamin B
6
), innate immunity (natural killer (NK) cell activity; folate) and act as
immunomodulatory for cellular immunity, especially with effects on cytotoxic cells (NK; CD8 + T lymphocytes; vitamin B
12
)
Vitamin C Maintains redox integrity of cells and protection against reactive oxygen species (ROS) generated during respiratory burst and inflammatory response
Stimulates leucocyte functions (neutrophil, monocytes movement)
Role in antimicrobial and NK cell activities, lymphocyte proliferation, chemotaxis and delayed-type hypersensitivity response
Decreases duration and severity of common cold
Se Antioxidant essential for optimal immune response, influencing both the innate and the acquired immunity
Deficiency impairs antibody production and causes viruses to undergo mutations to more virulent forms
Supplementation normalizes age-related decline in immune response
Zn Influences both innate and acquired immunity, supports Th1 response, helps to maintain skin and mucosal integrity
Deficiency leads to thymic atrophy, decreased cell-mediated cytotoxicity, helper T-cell and NK cell activities
Cu Part of Cu/Zn-superoxide dismutase, a key enzyme in the defence against ROS
Maintains intracellular antioxidant balance, suggesting an important role in inflammatory response
Adequate intake supports a Th1 response and both deficiency and oversupply modulate the immune response
Fe Essential for cell differentiation and growth, component of enzymes critical for functioning of immune cells
Involved in the regulation of cytokine production and action
Insufficient intake of micronutrients occurs in individuals 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 to less-effective innate and adaptive immune responses and increase
susceptibility to infections. Overall, inadequate intake and status of vitamins A, B
6
,B
12
, C, D and E and folate and of the trace elements
Se, Zn, Cu and Fe may lead to suppressed immunity, which predisposes to infections and aggravates malnutrition. Thus, supplementation
with a combination of these selected micronutrients can support the body’s natural defence system by enhancing all three levels of
immunity: epithelial barriers; cellular immunity; antibody production.
1. Wintergerst ES, Maggini S & Hornig DH (2006) Ann Nutr Met 50, 85–94.
2. Wintergerst ES, Maggini S & Hornig DH (2007) Ann Nutr Met 51, 301–323.
3. Maggini S, Wintergerst ES, Beveridge S & Hornig DH (2007) Br J Nutr 98, Suppl. 1, S29–S35.
Proceedings of the Nutrition Society (2008), 67 (OCE), E84 doi:10.1017/S0029665108006939