Our immune system evolved over millions of years and it is a complex, integrated whole-body system. Like everything else in our body, its ability to function at peak performance depends on how healthy and well-nourished we are. There are specific nutrients which are vital to our immunity and our susceptibility to disease can be increased if we are deficient in those nutrients. They include Vitamins A, C, and D and the minerals magnesium, zinc and selenium among others.
Many people have Vitamin D deficiency in the winter, which is when seasonal viruses like the common cold, influenza and Covid are more prevalent. This study, among many others, shows that those with the lowest level were far more likely to die of Covid19 than those with optimum levels. This study shows that vitamin D is important for the prevention of both flu and Covid. Supplementation is cheap and readily available and is a wise precaution during the winter. There is no downside to having optimum levels of vital nutrients. People have died of Covid because of Vitamin D deficiency. (During the summer of 2020 when official advice was rampant, we were allowed to exercise outdoors but we were not allowed to sit in the sunshine, even when alone. This prevented the accumulation of vitamin D stores. Why would they do that?)
Vitamin A: This study shows the importance of adequate levels of vitamin A for correct lung function and therefore the resistance of respiratory viruses. Vitamin A Deficiency and the Lung. This highlights the many benefits of Vitamin A
Both of these vitamins are fat soluble and likely to be low in people on a low-fat diet. They can also be low in people on a vegetarian or vegan diet because the best sources are in animal-based foods:
Vitamin A
Beef and lamb’s liver, salmon, tuna, mackerel, butter, cheese, eggs
Vitamin D
Salmon, tuna, herring, sardines, eggs, lard and bacon fat.
Of course, the best source of vitamin D is from sunlight on our skin (without sunscreen). However, during a British winter, it is not possible to get enough sunshine to create adequate amounts of this essential substance and we have to get it from our diet. It is worth remembering that it is a cholesterol molecule that is converted to vitamin D in the skin. Eating a lot of plant sterols (or taking statins) will reduce levels of cholesterol and potentially lower our immunity.
Vitamin C has an important part to play in our immune system. It improves the ability of immune and epithelial cells to function properly. Vitamin C and Immune Function
Diabetes During Covid and winter flu many of the fatalities were among people with diabetes. This study shows why that may not be a coincidence. Glycolytic control: A mechanism to regulate influenza viral infection
This is a quote from the Abstract of the study: “As new influenza virus strains emerge, finding new mechanisms to control infection is imperative. In this study, we found that we could control influenza infection of mammalian cells by altering the level of glucose given to cells. Higher glucose concentrations induced a dose-specific increase in influenza infection.”
A low-carbohydrate diet, as recommended on this site, has many more benefits than just weight loss and reversal of type 2 diabetes.
Minerals Some trace minerals have a profound effect on the integrity of our immune systems. Three of the most important ones are thought to be Zinc, Iodine and Selenium. They only occur in decent amounts in whole, unprocessed foods. Processing greatly reduces the mineral content.
Zinc is quite well-known for fighting the common cold. It is found in meat, shellfish, lentils and beans, nuts, dairy and eggs.
Iodine is essential for thyroid function and the thyroid is important for immunity. There are few good sources of iodine but the best include cod, tuna, shrimp, eggs, dairy, iodised salt and seaweed!
Selenium is an antioxidant that we require in trace amounts. Too little causes problems but so does too much. It is better to eat healthy foods than take supplements that may provide too much. The best sources of selenium are Brazil nuts, pork, beef, chicken, cottage cheese, eggs, mushrooms and spinach.
Good metabolic health, weight, blood sugar and an excellent immune system all come from eating the diet we evolved to eat: a low-carbohydrate diet of mainly animal-sourced protein and fat. What we eat can definitely improve our chances of fighting off the worst effects of any infection. Why do the NHS, Government and Chief Medical Officer never tell us this?