11.26.20 – News, Medical, Life Sciences
“Immunonutrition may improve COVID-19 patients' recovery”
By Dr. Anaya Mandal, MD

A person in white lab coat holding up two syringes.


Excerpts from this article: https://www.news-medical.net/news/20201126/Immunonutrition-may-improve-COVID-19-patients-recovery.aspx?utm_source=news_medical_newsletter&utm_medium=email&utm_campaign=infectious_diseases_newsletter_9_december_2020

Researchers duo Emma Derbyshire and Joanne Delange from the Nutritional Insight, Surrey, United Kingdom, explore the role of immunonutrition – nutrition that boosts or influences the immune system for those over 65 years of age in COVID-19. Their study titled, “COVID-19: is there a role for immunonutrition, particularly in the over 65s?,” was released in the latest issue of the BMJ Nutrition, Prevention and Health


…Public health strategies to prevent the spread of this highly infective virus (SARS-CoV-2) include social distancing, prevention of gatherings, wearing masks, and hand hygiene. The focus has not been on the immune system and foods that could help boost the immune system, write the researchers.

This review attempted to gather the present evidence in favor of immune-nutrition or nutrition and diet that helps boost the immune system, especially among the elderly who are more susceptible to the SARS CoV-2 infection and its complications…


The researchers explain that the definition of prehabilitation in scientific literature says these are “interventions that can help improve patient’s health in advanced of being exposed to a physiological stressor, so they are then better able to cope with that stress.”

Nutrition and disease

The researchers say that there is ample evidence that poor nutrition, protein-energy malnutrition as well as deficiencies of micronutrients such as vitamins and minerals are part of “related lifestyle factors” which can contribute to a suboptimally functioning immune system.

Certain components of the diet, including fruit, vitamin C, antioxidants, vitamins, minerals, and probiotics, are termed as immunonutrition that could help boost immunity and have a possible role in “resisting respiratory viruses and diseases,” write the researchers.

SARS CoV-2 and immune system

The immune system has four components - T cells, B cells, the complement system, and phagocytes. There are two arms of the immune system – innate and adaptive immunity. These protect the body against infections. A healthy diet and nutrition boost the immune system.

The team writes that Professor Philip Calder, an expert on immune nutrition, says in his paper, “Feeding the Immune System,” that the immune system functions by acting as a barrier against incoming infections.

Age and immune system

With age, the immune function declines. This is called ‘immunosenescence.’ Both innate and acquired immune systems decline with age. The reasons for this decline include:

  • Reducing functions of the T cells due to involution of the thymus gland and also reduced production of new naïve T cells
  • “Inflammaging” or inflammation associated with aging processes
  • Poor nutritional status associated with age. There is typically micronutrient deficiencies seen in the elderly
  • Menopause and andropause can also contribute to nutritional deficiencies

Immunonutrition and COVID-19

Some of the main findings from the scientific literature search by the researchers were:

  • A healthy immune system requires vitamins A, D, C, E, B6, B12, folate, copper, iron, zinc, and selenium. There is an interplay of these nutrients in a healthy immune system
  • Immunonutrients of considerable importance are vitamin C, D, and zinc.
  • Vitamin C helps in the development of the epithelial barrier functions of the respiratory system that prevents invasion by pathogens. It can help prevent pneumonia.
  • Vitamin D is a powerful immunoregulator. B and T lymphocytes, macrophages, and monocytes are some of the immune cells that have vitamin D receptors on their surface. Vitamin D has a protective role in respiratory infections
  • Authors write, “Zinc is regarded as a ‘gatekeeper’ of immune function.”


Eat foods rich in Vitamin C:

Broccoli (60mg/100g)
Blackcurrants (130 mg/100g)
Fortified breakfast cereals (up to 134 mg/100g)
Oranges (37-52 mg/100g)

Foods rich in natural zinc:

Canned crab (5.7mg/100g)
Canned shrimps (3.7gmg/100g)
Canned adzuki beans (≈2.3 mg/100 g)
Boiled eggs (1.3 mg/100 g)

Supplements containing:

10 mcg of Vitamin D daily (upper limit of 50 mcg)
Upper limit of zinc daily – 25 mg

Journal reference:

  • Derbyshire E, Delange JCOVID-19: is there a role for immunonutrition, particularly in the over 65s? BMJ Nutrition, Prevention & Health 2020;3, doi: 10.1136/bmjnph-2020-000071, https://nutrition.bmj.com/content/3/1/100