A 10-point summary on diet, nutrition and the role of micronutrients
E Fallon, S McAuliffe & S Ray on behalf of the NNEdPro Global Centre for Nutrition and Health (Design by M Abrantes; Reviewed by E Beck, L Buckner, J Bradfield, D Crocombe, M McGirr & K Martin) 26th March 2020. Correspondence to: info@nnedpro.org.uk
In the wake of the current and unprecedented COVID-19 pandemic, on 20th March 2020, the Director-General of the World Health Organization (WHO) emphasised the importance of appropriate diet and lifestyle measures including adequate nutrition to protect the immune system. This is of course not a substitute for adherence, first and foremost, to key public health and medical advice on prevention. However, as vast sections of society spend more time at home, it provides an opportunity to focus on strengthening the four lifestyle pillars of sleep, mind, exercise and diet. To elaborate on diet and nutrition, particularly given the variable quality of online information, we have put together a 10-point summary as general guidance:
1 The Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) is highly transmissible and can be potentially lethal. Hence any strategies that can prevent or mitigate respiratory infection risk and strengthen overall immunity are critical at this time.
2 Poor nutrition, due to either insufficient dietary intake of key nutrients or a poor overall diet quality, can compromise immune function and increase overall infection risk.
3 Micronutrients, commonly known as vitamins and minerals, are required in small quantities but are critical for health and pivotal in strengthening the immune system.
4 Multiple micronutrients are essential for good immune function, particularly vitamins A, C, D, E, B2 (riboflavin), B6 (pyridoxine), B12 (cobalamin) and B9 (folic acid) and minerals iron, selenium, zinc, magnesium and copper (Calder, Carr, Gombart & Eggersdorfer, 2020) and these are found in a variety of foods that form part of a balanced diet in line with national guidelines.
5 There are a variety of foods rich in vitamins and minerals (see below), in particular fruit and vegetables, which can be fresh, tinned or frozen:
6 In the United Kingdom, as an example, several micronutrient deficiencies are prevalent as the Government’s National Diet and Nutrition Survey (2019) demonstrates widespread inadequacy in the intakes and/or status of vitamin D, vitamin A (retinol), folate and selenium across the UK population and in specific age groups. This is likely to be mirrored more widely across multiple countries.
7 Certain individuals are at greater risk of micronutrient deficiency; this includes women of childbearing age, particularly pregnant and lactating women, infants and toddlers, children, adolescents (particularly females), older adults (Maggini, Pierre & Calder, 2018), obese individuals, and the critically ill, plus individuals with inflammatory bowel disease (Kilby, Mathias, Boisvenue, Heisler & Jones, 2019) and other chronic inflammatory and malabsorptive conditions.
8 In many high risk groups, a balanced diet alone may not be sufficient to meet these requirements and deficiencies can contribute to impaired immune function. This can be due to a variety of factors affecting intakes, absorption and also due to increased utilisation of micronutrients during times of infection. In such cases, the immune system can be supported by micronutrient supplementation particularly to help correct deficiencies.
9 As a key example from the UK, Vitamin D supplementation is recommended at 10 micrograms a day, as per guidelines. The average diet provides less than half of this amount. In fact, Public Health England (PHE) is now recommending that people consider taking a Vitamin D supplement of 10ug throughout the spring and summer as lockdown continues and access to sunlight may be limited. This is of particular concern in individuals in the high-risk category, which includes people who are housebound, living in a care home and those with darker skin.
10 Overall, whilst COVID-19 is causing inevitable distress to one and all, aside from the impact of the viral illness itself, prevention through social distancing and staying at home can affect both mood and feelings. This may cause depression, anxiety, loneliness and irritability. During these testing times, it is important to remember that eating well, staying hydrated, thinking positively, sleeping adequately and staying active will contribute to both physical and mental wellbeing. Some examples of useful UK resources include:
(i) NHS ‘stay at home’ exercises – https://www.nhs.uk/live-well/exercise/gym-free-exercises/
(ii) Doing things for others – www.actionforhappiness.org
(iii) A mental health community pack – https://www.maldon.gov.uk/healthandwellbeing
Stay well, stay safe and follow WHO and regional Government advice such as remaining at home and social distancing alongside meticulous hand-hygiene – diet and lifestyle measures are not a substitute for current public health advice on mitigation and suppression of the epidemic through our individual and collective actions – however, we hope that this rough guide will help health professionals, health caterers, policymakers and members of the public to gear up for the weeks ahead as we ride out the worst of the COVID-19.
NB Notes:
This is a rapid synthesis of best available evidence for a general/mixed audience – a series of peer reviewed publications aimed at professionals and policymakers will follow in our COVID-19 related special collection in BMJ Nutrition, Prevention and Health.
This article is intended to be general guidance only and is not geared to address the needs of specific population groups or individuals with disease conditions including those which can impact immunity and susceptibility to infection – for those with underlying conditions we ask that appropriately qualified medical and/or other health professionals are consulted at all times – the NNEdPro Global Centre cannot be held liable for any unintended consequences that arise due to the actions of individuals in response to this general article.
During this time there are a number of pieces of information online and in circulation which are of variable quality and integrity – please beware of ‘quackery’ and ‘profiteering’ behaviours and ensure that only trusted sources of information are followed.
Additional Recommended Reading
Check out our dedicated COVID19 and Nutrition Resources Microsite for further reading
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References
Alpert, P. (2017). The Role of Vitamins and Minerals on the Immune System. Home Health Care Management & Practice, 29(3), 199-202. doi: 10.1177/1084822317713300
BMJ 2017;356:i6583 http://dx.doi.org/10.1136/bmj.i6583
Calder, P.C.; Carr, A.C.; Gombart, A.F.; Eggersdorfer, M. Optimal Nutritional Status for a Well-Functioning Immune System is an Important Factor to Protect Against Viral Infections. Preprints 2020, 2020030199
Carr, A., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211. doi: 10.3390/nu9111211
Gammoh, N., & Rink, L. (2017). Zinc in Infection and Inflammation. Nutrients, 9(6), 624. doi: 10.3390/nu9060624
Kilby, K., Mathias, H., Boisvenue, L., Heisler, C., & Jones, J. (2019). Micronutrient Absorption and Related Outcomes in People with Inflammatory Bowel Disease: A Review. Nutrients, 11(6), 1388. doi: 10.3390/nu11061388
Kubenam, K. (1994) The Role of Magnesium in Immunity, Journal of Nutritional Immunology, 2:3, 107-126, DOI: 10.1300/J053v02n03_07
Maggini, S., Pierre, A., & Calder, P. (2018). Immune Function and Micronutrient Requirements Change over the Life Course. Nutrients, 10(10), 1531. doi: 10.3390/nu10101531
Moriguchi, S., & Muraga, M. (2000). Vitamin E and immunity. Vitamins & Hormones, 305-336. doi: 10.1016/s0083-6729(00)59011-6
National Diet and Nutrition Survey. (2019). Retrieved 25 March 2020, from https://www.gov.uk/government/collections/national-diet-and-nutrition-survey
Public Health England (2016). Government Dietary Recommendations (2016202). Retrieved from https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/618167/government_dietary_recommendations.pdf
Rayman, M. (2012). Selenium and human health. The Lancet, 379(9822), 1256-1268. doi: 10.1016/s0140-6736(11)61452-9
Verdrengh, M., Tarkowski, A. Riboflavin in innate and acquired immune responses. Inflamm. res. 54, 390–393 (2005). https://doi.org/10.1007/s00011-005-1372-7
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