Our immunity is comprised of all mechanisms used to defend our bodies against viruses, bacteria, parasites and other threats we may encounter. The link between proper nutrition and immunity is strong and there is growing awareness of how vital it is to consume appropriate amounts of both macro and micronutrients for optimal immune health.
In the summary below, we look at some of the many vitamins and minerals required to give our immune system what it needs to aid in the fight against harmful pathogens.
The antimicrobial properties of vitamin A may play a role in the fight against certain viral diseases1. Vitamin A also exerts antioxidant effects and has protective roles in certain disease complications1. Animal sources are commonly found in meat, fish and eggs. Provitamin A carotenoids are converted into Vitamin A once ingested. These carotenoids are responsible for the orange colour of certain foods and are therefore found in things such as sweet potato, carrots, bell peppers and mango.
Vitamins B1, B2, B3, B5, B6, B7, B9 and B12 are water-soluble vitamins that are involved in, among other things, maintaining healthy blood cells, creating new blood cells and preventing infections. B vitamins are largely found in both animal and plant-based sources. They are also found in smaller amounts in unrefined carbohydrates such as oats, brown rice and whole-grain bread. Vitamin B complex (supplements containing all 8 forms) plays an important role in the interaction between immune cells involved in inflammation1. Deficiencies of B vitamins can be detrimental for our overall health and well-being. For example, Vitamin B1 contributes to the metabolism of glucose, fat and protein1. This results in the production of energy required to carry out daily activities. Deficiencies may also negatively impact the nervous system and result in neuronal cell damage1. Vitamins B6, B9 and B12 work together to contribute to overall immune response and proper functioning of the immune system1.
Vitamin C has been shown throughout the years to demonstrate positive effects on our overall health and immunity. Research is still developing with vitamin C’s role in COVID-19 and studies are currently being done in Italy as well as China1. Adequate intake of vitamin C has been shown to strengthen the immune system through collagen synthesis enhancement and improved healing processes1.
The natural form of vitamin D, also known as cholecalciferol, is found in oily fish (salmon, sardines, mackerel), egg yolks and certain fortified foods. It can also be produced in the skin in the presence of UV radiation. Increased time spent indoors may increase the risk of vitamin D deficiencies1. Calcium, magnesium and phosphate are three essential minerals which rely on homeostasis in order to carry out their functions1. Vitamin D plays an essential role in carrying out this mineral homeostasis1. There is also evidence suggesting that vitamin D plays a role in immune system regulation. It improves natural protective barriers and enhances adaptive immunity1.
Free radicals are unstable atoms found in the body that break down cells over time. Certain conditions result in an increasing amount of free radicals in our bodies resulting in oxidation and cell damage. Vitamin E is a potent antioxidant capable of protecting our cells from free radicals. Vitamin E is found in nuts and seeds (almonds, hazelnuts, sunflower seeds), green vegetables (spinach, broccoli) and certain vegetable oils1. Certain cereal and margarine brands often add vitamin E to their product so be sure to check product labels when purchasing these items in the future.
Zinc is an essential mineral required for processes such as healing damaged tissue, forming DNA and strengthening one’s immune system. It plays a role in cell growth and development and is therefore essential for times of growth such as adolescence and pregnancy. Foods rich in zinc include meat, fish and poultry. Plant based sources include legumes, whole-grains, nuts and seeds.
Selenium is another powerful antioxidant that reduces oxidative stress by neutralizing excess free radicals. It plays a role in our mental health, lowering inflammation and improving our immunity. Dietary sources of selenium include oysters, sardines, sunflower seeds, brazil nuts, tuna and eggs to name a few.
The food and drinks we fuel our bodies with can affect the manner in which our bodies fight off certain infections. It is important to note that no foods, drinks or supplements can prevent or cure COVID-19 infections*. Providing your body with proper nutrition through adequate vitamin and mineral intake can decrease the possibility of developing other health conditions.
*Please note: currently, no research exists supporting supplement use to protect against COVID-19 specifically.
1: Thomas H Jovic, Stephen R Al, Nader Ibrahim et al.(2020). Could Vitamins Help in the Fight Against COVID-19? Nutrients, 12(2550); doi:10.3390/nu12092550.
Written by: Nicole Keeling – Registered Dietitian, @cape.townfoods