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Fuel and Protect

As you are all very much aware by now, COVID-19 has been spreading throughout the Irish community and steps are being taken nationwide in order to decrease the rate at which this virus is spreading.

Given the mass closures of schools, public buildings and businesses all over the country (ours included), its no wonder that many of you are starting to worry about the very real potential of the virus affecting your health.

With this in mind, I decided to put together some useful nutrition and lifestyle information to hopefully alleviate some of your concerns, and show you that there are plenty of small steps that you can take within your everyday life that could help boost your immune system and protect you from COVID-19.

While we aren’t medical professionals or dieticians, a little bit of research seems to show that we can help prepare ourselves for COVID-19 by bolstering our immune systems and preparing our bodies to deal with this unwanted visitor should it come knocking on our door. As always, please do keep in mind that our number #1 recommendation is to listen to the advice of experts and medical professionals.

Vitamins and minerals that have been proven through research that help maintain a healthy immune system include Vitamin A , deficiencies of which have been linked to respiratory illness (Calder, 2013) and

beta-carotene, folic acid, vitamin B6, vitamin B12, vitamin C, vitamin E, riboflavin, iron, zinc and selenium (Marcos, Nova and Montero, 2003).

While maintaining adequate levels of these nutrients is no guarantee that we will stay healthy, it definitely can’t hurt to try and stay on top of these levels in the current climate.

Good sources of these vitamins include eggs as well as orange and yellow fruit and veg (vitamin A); sweet potatoes (beta-carotene) and carrots (beta-carotene); meat, fish and soya beans (vitamin B6 and B12); citrus fruits, broccoli and cauliflower (vitamin C); nuts and vegetable oils (vitamin E); eggs, milk and green veg (riboflavin); red meat, beans and lentils (iron); red meat, poultry, nuts and chickpeas (zinc); and brazil nuts and fish (selenium).

As we can see there are many varieties of foods I have mentioned here that will contribute to boosting the immune system by providing some useful micronutrients (so many in fact that I had to leave several of them out!).

This list isn’t intended to make us "panic buy" everything en masse, but to show us that by maintaining a healthy and balanced diet, we will do our immune system the world of good.

Another review by Mora, Iwata and von Andrian (2008) highlights the importance of Vitamin A and Vitamin D specifically within our immune system. While B Vitamins and Vitamin C can assist our immune systems in a number of ways, such as acting as antioxidants, the authors tell us that Vitamin A and Vitamin D have specific roles to play in keeping our immune system up and running (be prepared for some heavy-ish science about to come up in the next paragraph).

Brace yourselves:

Vitamin D has an important role to play in the phagocytic activity of the immune system (when white blood cells “eat” unwanted visitors in our cells, like bacteria). Within the phagosome where the bacteria is housed inside a cell following phagocytosis, peptides such as cathelocidin localise within the phagosome and have potent anti-microbacterial functions. In other words, once the unwanted bacteria is stored in a contained part of the cell, housed in a structure purpose-built to contain it called a phagosome, these peptides come in and help get rid of the problem. It turns out that production (transcription, technically speaking) of cathelocidin is heavily dependent on circulating levels of Vitamin D (Aranow, 2011).

...Does anybody else's head hurt right now ?!?!

That being said, Vitamin D is notoriously tough to come by for us here in Ireland given our lack of direct sunlight, but there are some other natural sources that we can exploit to try and get more in our diets, most notably being fresh fish and cod liver oil (Holick, 2007).

There are other fortified foods and supplements that we can avail of should we feel like we need to, but the best sources of Vitamin D, apart from direct exposure to sunlight, are the ones I mentioned earlier.

Now while Vitamin D may seem to have a primarily anti-bacterial role in our immune system, there is evidence that says it can help protect us from respiratory infections (Ginde, Mansbach and Camargo Jr., 2009).

While this may not directly prevent against a viral infection such as COVID-19, it has been noted that having an already compromised respiratory system might make us more susceptible to the virus’ effects.

By trying to get as much Vitamin D as we can, we can help to keep our respiratory system healthy and put ourselves in the best position possible to fight the virus.

Vitamin A also has an important role to play in several of the immune system’s functions (Stephenson, 2001). Stephenson goes on to say in his article that Vitamin A deficiency can negatively impact the mucosal epithelial barriers found in the eye, the respiratory tract, the gastrointestinal tract and the urogenital tract.

These barriers separate these different tracts from the rest of the body and can have different functions and effects depending on their location in the body.

For example, the intestinal epithelial barrier prevents hostile substances from entering the tract, but it also allows for the secretion of waste from the tract and intake of nutrients into the tract through selective permeability (Turner, 2009).

The importance of the mucosal immune system is huge, with over 80% of immune cells in a healthy adult human produced in our mucosal systems (Holmgren and Czerkinsky, 2005). Vitamin A can be such a boost to our immune system, that it has been called the “anti-infective vitamin” by some (Semba, 1994). It seems clear from these pieces of research that Vitamin A can give our immune system a much needed boost when we need it. One thing to note however is that Vitamin A is a fat-soluble vitamin and if we consume too much of it we can make ourselves ill.

Beyond micronutrients, if we even look at our food from the macronutrient level (as I’m sure some of us have tried counting, or are still counting our macros), a balanced and adequate intake of our three main macronutrient groups will help a tonne.

The adequate intake of carbohydrate and fat will spare our proteins and allow us to have our protein perform some key functions in our immune system that the other two nutrients cannot do.

In fact, it has been seen that protein-specific malnutrition can undermine the body’s response to a foreign “visitor” (Calder, 2013). Vegetarians be warned!

Many of us are already putting some level of thought into our macronutrient intake, whether we are fully tracking everything that we eat, or just trying to keep a loose idea of if you have had enough protein today.

By continuing to do so, you are taking great steps to maintaining a healthy diet.

So don’t worry, just keep doing what you’re doing and I’m sure that you will help yourself to stay on top of your immune system’s health.

Alongside of these dietary precautions, we can also help our immune system’s function, in particular our immune system’s adaptability and “memory” as it were. Some studies seem to indicate that a lack of restful sleep can negatively affect the natural peaks and troughs of immune cells present in peripheral blood.

It has also been seen that concentrations of IL-7, which supports T cell growth and differentiation of memory T cells, are enhanced during sleep (Besedovsky, Lange and Born, 2011).

T cells are important for activating the immune cells to fight infections.

So, while it is often not entirely possibly, getting our recommended 6-8 hours of sleep every night could help keep us healthy against the spread of COVID-19.

Sleep loss, or sleeping less than 6 hours per night on average, can have a wide array of health consequences such as an increased likelihood of obesity, reduced effectiveness of vaccinations and increased risk for heart attack (when we sleep less than 5 hours per night) being some of the most serious potential ramifications (Imeri and Opp, 2009).

While sleep is something that many of us struggle with and in times like these where stress can be quite high, some of us are undoubtedly struggling to get a good night’s sleep every night. What is promising though is that a study done in the University of Reading on students showed that by attending a sleep hygiene talk, the students who did so were able to drastically improve their self-reported sleep length and quality (Gregor, Wiggs and Ho, 2019).

Simple guidelines that we can follow to help improve our sleep include trying to get up and go to bed at around the same time everyday, not consuming stimulants like caffeine too late in the day (depending on your own schedule), avoiding screen time for 30-60 minutes before you go to bed and doing something boring or mundane before you go to sleep.

For instance, if you are reading a book before bed (a common recommendation) then make sure you aren’t reading a scintillating page-turner that will keep you up all hours wanting to know what happens next. Perhaps printing this article and having it ready to read might help you nod off in the evening!

The take home message here is that by following along with our common sense and eating healthily, getting plenty of sleep and following other lifestyle and nutritional guidelines that we continuously espouse as being key to longevity, we can help shore ourselves up against suffering from any kind of infection, notably the current spread of COVID-19.

While this is not an exhaustive list of the different means of protecting ourselves from the virus, it will hopefully give you all some useful information and reassure you that there are plenty of simple measures that we can take to try and stay healthy during this difficult time.

Finally, as per what I said at the start of this article, please do take this with a pinch of salt. I’m far and away from ever being a doctor, dietician or immunologist so listen to the experts and what they have to say during these difficult times.

While this list provides some simple ways to help boost our immune function regardless of the circumstances, listen to the HSE and adhere to their guidelines. This is what will be most effective for curtailing the spread of COVID-19.

Stay safe and healthy, wash your hands and I look forward to seeing you all again soon!

Coach Ian


Aranow, C. (2011). Vitamin D and the immune system. Journal of Investigative Medicine, 59(6), pp.881-886.

Besedovsky, L., Lange, T. and Born, J. (2012). Sleep and immune function. Pflügers Archiv-European Journal of Physiology, 463(1), pp.121-137.

Calder, P.C. (2013). Feeding the immune system. Proceedings of the Nutrition Society, 72(3), pp.299-309.

Ginde, A.A., Mansbach, J.M. and Camargo Jr., C.A. (2009). Association between serum 25-hydroxyvitamin D level and upper respiratory tract infection in the third national health and nutrition examination survey. Arch Intern Med, 169(4), pp.384-390.

Gregor, C., Wiggs, L. and Ho, A. (2019). The benefits of psychoeducation for improving sleep quality. University and College Counselling, 7(2), pp.16-21.

Holick, M.F. (2007). Vitamin D deficiency. New England Journal of Medicine, 357, pp.266-281.

Holmgren, J. and Czerkinsky, C. (2005). Mucosal immunity and vaccines. Nature Medicine, 11(4), pp.S45-S53.

Imeri, L. and Opp, M.R. (2009). How (and why) the immune system makes us sleep. Nature Reviews Neuroscience, 10(3), pp.199-210.

Marcos, A., Nova, E. and Montero, A. (2003). Changes in the immune system are conditioned by nutrition. European journal of clinical nutrition, 57(1), pp.S66-S69.

Mora, J.R., Iwata, M. and von Andrian, U.H. (2008). Vitamin effects on the immune system: Vitamins A and D take centre stage. Nature Reviews Immunology, 8(9), pp.685-698.

Semba, R.D. (1994). Vitamin A, immunity and infection. Clinical Infectious Diseases, 19, pp.489-499.

Stephenson, C.B. (2001). Vitamin A, infection, and immune function. Annual Review of Nutrition, 21(1), pp.167-192.

Turner, J.R. (2009). Intestinal mucosal barrier function in health and disease. Nature Reviews Immunology, 9, pp.799-809.

At Nikafit Studios we are dedicated to an excellent standard of small group personal training. At Nikafit we deliver our results based personal training programs, in a friendly but focused small group training setting, allowing our clients to receive elite level personal training at a fraction of the cost of a 1-on-1 personal training session. Nikafit’s semi-private personal training is focussed on the needs of our clients and the small group personal training coach to member ratio’s at Nikafit Studios allow the best service possible. At Nikafit we are changing lives through fitness.

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