Talking Nutrition Editors
Hear from Dr. Peter Van Dael, SVP Nutrition Science and Advocacy at DSM, talk about the role of nutrition in supporting a strong immune system and the importance of a sufficient intake of immune-boosting nutrients:
Consumers are increasingly aware of the importance of the role nutrition plays in supporting their general health and wellbeing, and specifically their immunity. In a recent consumer survey, 71% of consumers said they are implementing measures to improve their diet and nutrition, increase levels of physical exercise or consume dietary supplements, to improve their immunity.1 However, while there’s a clear link between the benefits of supplementation and immune health, consumers do not always adopt a consistent approach to taking dietary supplements, for example only taking them during the winter months or when they have already become ill.
To truly support optimal immune health, there is a need to increase awareness of the important of taking the right nutrients, at the right amount, at the right time.
Acute respiratory tract infections, which can prevent normal breathing function, are one of the major causes of death around the world. The World Health Organization (WHO) estimates that globally, seasonal influenza alone can result in 3-5 million cases of severe illness that require hospitalization, as well as cause 290,000-650,000 deaths annually.2
Maintaining an optimal immune system is therefore crucial to reducing the impact of infection, as well as being important for overall health and wellbeing. The immune system is complex and comprises two complementary responses: the innate and adaptive responses. The innate response works by providing physical barriers to help pathogen entry, as well as white blood cells and molecules that are ready to act immediately upon an infection. In contrast, the adaptive response takes time to develop, but is highly specific and targeted, and creates the immunological “memory” that prevents re-infection with the same pathogen twice. Memory is also the mechanism by which vaccinations help prevent disease. Adaptive immunity is composed of cells like B cells, which make antibodies, and T cells, which kill virally infected cells. Both innate and adaptive immunity are key to operating an effective immune system.
Although vaccination programs for diseases such as influenza and stringent hygiene practices are already widely recommended, cases such as the recent novel coronavirus pandemic show that additional measures are needed to further reduce the impact of viral infections, and in particular respiratory tract infections, to protect public health.
The role of nutrients in maintaining – and improving – immunity is well established it is often not implemented in public health strategies. However, a recent expert opinion which is currently undergoing the peer-review process, has outlined the important role that vitamins, minerals and other nutritional ingredients play in this area.3 The expert opinion highlights the positive impact of vitamins A, B6, B12, C, D, E and folate for both the innate and adaptive immune systems.4 Nutrients such as omega-3s have also been found to support an optimal immune system, by helping resolve the inflammatory response.5 Not only have certain micronutrients been shown to make a difference, but there is also increasing evidence to suggest nutrient deficiencies could negatively affect immune function, and even potentially decrease resistance to infections.6
Vitamin C supplementation has been found to reduce the risk of pneumonia, particularly in those with low dietary intakes.7 It has also shown to decrease the duration and severity of upper respiratory tract infections.8 Several recent meta-analyses have also concluded that vitamin D supplementation in fact does reduce the incidence of respiratory infection.9
Despite their essential metabolic functions and the benefits of micronutrients supporting the risk of respiratory tract infections, dietary intake worldwide remains generally low compared to the recommended daily allowance (RDA). For example, in Europe, all age groups have a proportion at risk for inadequate intake in vitamins D, E, folate and selenium, with the intake of vitamin C remaining low in specific demographics.10
However, the expert opinion states that for some micronutrients the intake may need to be above the RDA to provide optimal immune support. For example, during an infection, vitamin C stores can become depleted and therefore require higher levels to return to normal blood levels. The paper makes recommendations for a daily intake of at least 200 mg/day of vitamin C and 2,000 IU (50 µg) vitamin D for healthy individuals – which are above the US RDAs. Given the supporting evidence for omega-3s, it also suggests that 250 mg/day eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) would help provide the necessary inflammatory benefits to optimize immunity.
It’s important to remember that the RDA is set to meet basic nutritional needs for healthy individuals. In certain disease states, the body – specifically the innate and adaptive immune systems – need additional nutrients to boost the immune system and fight against infections. There is a big range between the RDA and upper safe intake level which means consumers can look to increase their intake of essential nutrients through diet and supplementation to build optimal immunity.
Given the supporting evidence, including nutritional supplementation as part of future public health strategies could be extremely beneficial in boosting immune function. Although current practices such as vaccinations and hygiene measures can help limit the spread of infection, additional support through supplementation is a safe, effective and low-cost way to help public health, by supporting optimal immune response, a key response of our body in managing infectious diseases.
 DSM, ‘Global health concerns’, [report], 2017.
 World Health Organization Influenza (Seasonal). Available online: https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal) (accessed on Mar 2, 2020).
 Calder, P.C. et al, ‘Optimal Nutritional Status for a Well-Functioning Immune System is an Important Factor to Protect Against Viral Infections’, Preprints 2020, 2020030199
 Calder, P.C. ‘Omega-3 polyunsaturated fatty acids and inflammatory processes: nutrition or pharmacology?’, Br J Clin Pharmacol,2012, 75, 645–662.
 Calder, P.C. et al, Preprints 2020
 Hemilä, H. et al, ‘Vitamin C for preventing and treating pneumonia’, Cochrane Database of Systematic Reviews 2013, 8, CD005532.
 Hemilä, H. ‘Vitamin C and infections’, Nutrients, 2017, 9, 339.
 Martineau, A.R.et al, ‘Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data’, BMJ, 2017, 356, i6583.
 Gombart, A.F. et al, ‘A review of micronutrients and the immune system–working in harmony to reduce the risk of infection’, Nutrients, 2020, 12, 236.