Protecting yourself against viral respiratory diseases, like influenza and COVID-19, is an important part of living a healthy life. Besides the well-known things you can do to protect yourself, like vaccinations, washing your hands, staying home if you are sick and avoiding other people who are sick, have you ever thought about what you are eating in terms of protecting yourself? Are you eating the rainbow? Vitamins that enhance your immune system are found in almost all fruits and vegetables; so eating fruits and vegetables of all colors ensures you're getting vitamins! This part of immunity is often disregarded during public health discussions but plays a very important role in staying healthy. There are many different things to consider regarding nutrition and the immune system but for now let’s focus on vitamins; specifically, vitamins C, D and E. The immune system can be broken down into two response categories; innate and adaptive. The innate response includes physical barriers like the skin, gut, epithelium and phagocytic cells and is fast to quickly recognize pathogens to kill them. (1) This causes inflammation, which you feel in the form of a fever. The innate response continues to resolve that inflammation, so the bodies temperature can go back to normal. The adaptive response includes lymphocyte cells and is slower, but generates the immune systems memory to aid in killing pathogens it comes across multiple times. (1) On the innate side vitamins help to support the growth of physical barriers and phagocytic cells and promotes quick recovery from the inflammation caused in killing pathogens. (2) On the adaptive side vitamins help the development of lymphocytes which provides better memory support. (2) Most vitamins provide these effects but vitamins C, D and E have been researched the most and have the largest impacts. Foods rich in vitamins C include broccoli, cauliflower, oranges/orange juice, sweet potatoes, tomatoes, peppers and most other fruits and vegetables. Vitamin D is found in salmon, tuna fish, eggs, mushrooms, and orange juice. Because these vitamins help support the inflammatory response as well as cellular memory, deficiencies in either of these can lead to a prolonged inflammatory state and a weaker fight against reoccurring pathogens. In the case of COVID-19 this is important. From what we know about COVID-19 it causes uncontrolled cellular inflammation in your body, leading to the high persistent fever. (3) The body of someone who has a vitamin D or C deficiency is already at a disadvantage in resolving inflammation. If they then come into contact with COVID-19 the inflammation could be too much for their cells to fight against on their own. Vitamin E also has an affect on immunity. Vitamin E supplementation has been shown to enhance lymphocytes when given to those with low vitamin E status creating a better cellular memory for the fight against reoccurring pathogens. (2) The best way to keep vitamin C, D and E levels up is by consumption of foods high in those vitamins; but when this isn’t possible vitamin supplementation is the next best option to help the fight in staying healthy!
1. Information NC for B, Pike USNL of M 8600 R, MD B, Usa 20894. The Innate and Adaptive Immune Systems. Institute for Quality and Efficiency in Health Care (IQWiG); 2016. Accessed May 4, 2020. https://www.ncbi.nlm.nih.gov/books/NBK279396/
2. Calder PC, Carr AC, Gombart AF, Eggersdorfer M. Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect against Viral Infections. Nutrients. 2020;12(4):1181. doi:10.3390/nu12041181
3. Wadman M, Couzin-Frankel J, Kaiser J, MatacicApr. 17 C, 2020, Pm 6:45. How does coronavirus kill? Clinicians trace a ferocious rampage through the body, from brain to toes. Science | AAAS. Published April 17, 2020. Accessed May 4, 2020. https://www.sciencemag.org/news/2020/04/how-does-coronavirus-kill-clinicians-trace-ferocious-rampage-through-body-brain-toes