So I felt compelled to put together an article to help you make informed decisions about keeping your immune system strong.

Yes, I wanted to cover the topic of ways to boost your immune system for COVID-19. However, it applies to all potential socially spread illnesses.

Yes, this is scary for most, but all we can do is put effort into the things we can control.

And you have control of how you care for your own body, period.

And let me preface that I’m not an immunologist or a medical doctor. But I do have a formal education in how food affects our physiology. So my input is based on three things.

  1. My education,
  2. my experience and
  3. review of current peer-reviewed research

This is not based on selling you a supplement or false claims.

I put a great deal of effort into interpreting quality research to help you better understand any claims.

Please don’t get roped into miracle cures or junk supplements.

Glynn’s Guide:
Takeaways That Won’t Fail You

  • Getting too little of a micronutrient will have a larger impact than megadosing with another nutrient.
  • Eliminating sugar, alcohol and heavily processed foods will really help your immune system.
  • Vitamin C has been shown to help with COVID-19. Because we can tolerate a lot of it, there’s no reason not to supplement additional.
  • Staying fit, sleeping well and minimizing stress will also help keep your immune system in peak performance.

What factors affect the immune system?

There are so many factors that affect the immune system, but several that we have control over are important.

Perhaps one of the most important factors is a weakened immune system from inadequate nutrition.

Calder states,

“There are large inter-individual variations in many immune functions even among the healthy. Genetics, age, gender, smoking habits, habitual levels of exercise, alcohol consumption, diet, stage in the female menstrual cycle, stress, history of infections and vaccinations, and early life experiences are likely to be important contributors to the observed variation.” [c]

What causes a weak immune system?

What causes a weak immune system

Here’s a list of major contributors of a weakened immune system for which you have control:

  • Inadequate nutrition. This can be in the form of too many calories from junk food and not enough from healthy foods. In other words, you’re satiated but malnourished.
  • A lack of exercise.
  • Chronic stress.
  • Smoking
  • Excessive alcohol consumption. [e]
  • Poor sleeping habits.
  • Obesity

Unfortunately, many cultures have adopted the western style of eating. I’m talking about the excess consumption of highly processed convenience foods and too much sugar.

We also tend to be lazy and creatures of convenience. I’m not trying to offend you. I’m only trying to cut through the BS and help.

If you ever needed a good reason to improve how you eat, this is it! Over the years, I’ve only experienced one situation that motivates people more than anything else. Fear! So consider this a green light to make improvements now.

Here’s a list of things not to do if you’re trying to keep your immune system strong:

  • Smoking.
  • Excessive sugar intake.
  • Too many pre-packaged convenience foods.
  • Drink alcohol heavily.

How does alcohol affect the immune system?

Acute and chronic alcohol abuse wreaks havoc on the immune system. The following systems are affected:

  • Alcohol causes excessive intestinal permeability.
  • Chronic alcohol exposure also contributes to acute respiratory distress syndrome (ARDS) or acute lung injury.
  • Alcohol abuse reduces the level of antioxidants in the lungs.
  • Excess alcohol use increases the mortality rate from pneumonia.
  • Chronic alcohol exposure is associated with proinflammatory cytokines.

What to eat for a strong immune system

What to eat for strong immune system

A lot of it has to do with obtaining adequate nutrients and your gut health. I know that “gut health” is thrown around a lot lately, but it’s valid.

There are many foods to avoid and a few to add. But when based on the typical western diet, it’s more about what to avoid eating for a strong immune system.

What nutrients play a large role in our immune system (that you’ve heard of)?

nutrients immune system

The following nutrients play a key role in the regulation of our immune system:

  • Essential amino acids
  • Omega-3 fatty acids
  • Vitamin A
  • Vitamin D
  • Folic acid
  • B vitamins
  • Vitamin C
  • Zinc
  • Copper
  • Selenium

A quality diet that includes plenty of veggies, fish, lean meat and fibrous starches will supply all of the above mentioned. If you feel the need, a multi-vitamin will fill in any gaps. We’ll discuss taking additional micronutrients below.

The role of specific nutrients in the immune system

Protein and essential amino acids: During an illness, amino acids are used for inflammatory and immune proteins rather than growth and repair.

And Li states,

“A deficiency of dietary protein or amino acids has long been known to impair immune function and increase the susceptibility of animals and humans to infectious disease.” [i]

  • Omega-3 fatty acids: They have anti-inflammatory properties. [j]
  • Vitamin A: It plays a role in T-lymphocyte function and antibody response to infections.
  • Vitamin D: If you have a deficiency, you’re more susceptible to infection and increased autoimmunity. [k]
  • Folic acid: A deficiency weakens the immune system.
  • B Vitamins: A deficiency weakens the immune system.
  • Vitamin C: Vitamin C contributes to microbial killing in many ways. It’s also shown to prevent and treat respiratory problems.
  • Zinc: A deficiency in zinc interferes in the function of primary T cells.
  • Copper: It contributes to immune functions beyond the scope of this article.
  • Selenium: It plays a role in our lymphocyte production and function.

Best supplements to boost immune system

Best supplements to boost immune system

Making sure we’re getting adequate levels of all nutrients is essential. I want to emphasize that a deficiency in a particular nutrient has a larger overall impact than megadosing another nutrient.

I’ve incorporated a table from Lei Zhang specifying specific nutrients that have shown to be beneficial to several different viral infections. [d]

Vitamin A Measles virus, human immunodeficiency virus, avian coronavirus
B vitamins MERS‐CoV; ventilator‐induced lung injury
Vitamin C Avian coronavirus; lower respiratory tract infections
Vitamin D Bovine coronavirus
Vitamin E Coxsackievirus, bovine coronavirus
Omega‐3 polyunsaturated fatty acids (PUFA) Influenza virus, human immunodeficiency virus
Selenium Influenza virus, avian coronavirus; viral mutations
Zinc Measles virus, SARS‐CoV
Iron Viral mutations
Chinese medicine SARS‐CoV, avian infectious bronchitis virus

Perhaps one of the most beneficial supplements is Vitamin C. Vitamin A, the B vitamins and selenium seem to play a role in treatment as well.

I caution you not to megadose Vitamin A. That’s dangerous. Leave that to the medical staff. But due to the nature of vitamin C, you can take a lot without harm. And it’s inexpensive.

When do supplements help the immune system the most?

If you eat a poor diet deficient in any particular micronutrients, adding them back in via a supplement will help. This again begs the question as to whether megadosing any particular nutrients will help.

As stated earlier, Vitamin C seems to be the most important vitamin to megadose (and it’s safe). Zhang states

“Three human controlled trials had reported that there was a significantly lower incidence of pneumonia in vitamin C‐supplemented groups, suggesting that vitamin C might prevent the susceptibility to lower respiratory tract infections under certain conditions. The COVID‐19 had been reported to cause lower respiratory tract infection, so vitamin C could be one of the effective choices for the treatment of COVID‐19.” [d]

Carr states, “Furthermore, supplementation with vitamin C appears to be able to both prevent and treat respiratory and systemic infections.” [m]

Because of its low cost and low toxicity, I would add it to your arsenal.

Does megadosing any particular nutrient support your immune system?

Vitamin C immune system

I was surprised to find such a strong recommendation from the most recent research on COVID-19 to megadose Vitamin C. It’s the only one I would megadose.

You can take 50mg of zinc for a brief period without any issues. Too long and you interfere with other nutrients (copper). Zinc has been shown to help the immune system operate at peak performance.

Do not megadose Vitamin A. That’s dangerous and should be left to the medical professionals.

What about spices for immune system improvements?

Spices for immune system

Ever since I’ve been involved in this industry, nutrients and spices have surfaced with claims that they improve this or that. With that said, let’s address some of the more recent spices in the news.

  • Curcumin is an anti-inflammatory that helps modulate the immune system.
  • Garlic might support the immune system. I couldn’t find a lot of literature supporting its use for illnesses. But it does have other positive properties, so add it to your arsenal.
  • Ginger is definitely good for acute GI disorders and it seems to be more associated with cancer treatment.
  • Cinnamon may have anti-inflammatory properties. But more closely related to allergic reactions.
  • Cayenne pepper did not turn up any evidence in the literature that’s applicable to this article.

Should you add any of these spices? I see no reason not to since they’re healthy, to begin with anyway.

Sleep and your immune system

Sleep and Immune System

Does sleep help your immune system?

You bet it does!

Bryant states “that sleep deprivation has detrimental effects on immune-cell number, function and cytokine production.” [g] So, yes we need adequate sleep to keep our immune systems operating at peak.

The following are immediate actions you can take to improve your sleep:

  • Eliminate screen time an hour before bed.
  • Go to bed the same time every night.
  • Do not eat right before bed.
  • Avoid alcohol 3-4 hours before sleep.
  • Stretch and meditate right before climbing into bed.

Does exercise boost your immune system?

Does Exercise Boost Your Immune System

There is certainly evidence that exercise boosts your immune system to operate at peak performance. [h] Too much exercise can have the opposite effect and weaken it.

If you’re on lockdown during this current outbreak, I suggest:

  • walking outside briskly
  • following a home strength training program
  • doing Yoga
  • jumping rope
  • or simply sprint/walk intervals outside

If you’re able to stay active, exercising to keep the immune system operating at peak performance can be crucial.

Will eating too little impair your immune system?

Yes. You still need the calories to “fuel the engine.” In fact, if you’re consuming all the wrong calories (junk), you’re technically still undernourished of essential nutrients. In other words, you can eat enough to be full, but if it’s all junk food, you’re still malnourished.

Also, too few calories from quality foods and you may end up deficient in a particular micronutrient. Again, a deficiency in any micronutrient has a large negative impact on your immune system.

Are edible mushrooms beneficial to your immune system?

mushrooms nutrition

Since I just covered this topic in a recent article: The Health Benefits of Mushrooms [A Definitive Guide], I felt compelled to include mushrooms.

Yes, I believe mushrooms can help with many aspects of the immune system. If you’re willing to either add them to your diet or supplement, they could prove beneficial. Again, you can get more information about different types of mushrooms in my previous article about mushrooms.

Chronic stress is not helpful to your immune system!

Short term events (such as exams) have minimal effect on one’s immune system. But long term (chronic) stress has a negative impact on one’s immune system. Learning to meditate or take some time for yourself can go a long way in helping your immune system. [b]

Does your gut’s microbiome play a role?

We’re still learning a great deal about this relationship we have with the bacteria in our gut. There is certainly evidence that it plays a role. Much of it is beyond the scope of this article.

Myles states, “Dietary simple sugars appear to lead to dysbiosis directly through changes in local nutrient concentrations and bacterial functions that may favor harmful taxa over the beneficial commensals.” [a]

How to boost your child’s immune system

How to Boost Childs Immune System

Because I have two children of my own, I want to at least cover the topic briefly. I am not an expert in childhood nutrition, but many of the same applications for adults are applicable to children.

Keep in mind that because children are growing, they have additional nutritional needs. The following nutrients are important to consider:

  • There’s an additional need for protein. Keep in mind, that means more grams per kilogram than an adult (as a minimum), but it’s still a low number based on body weight. If you stick with 1.1 grams/kg or more you’ll hit the mark for a strong immune system.
  • Make sure they are getting adequate levels of Vitamin D. Instead of listing all the best foods, (you can look that up), try to keep whole veggies, fruits, and unprocessed foods in their diet.
  • Make sure they’re getting enough zinc. It’s important for their growth and immune system.

There are several practices that will also help boost your child’s immune system:

  • Make sure they are consuming a lot of water no matter what. Save any fruit juices for if they are ill and have no appetite.
  • Consistent quality sleep is imperative to your child’s immune system. Until they’re teenagers, they should be sleeping twelve hours a night for many reasons.
  • Keep them active and stress-free. Spend some time with your kids. Remember chronic stress can weaken the immune system.
  • Aside from adequate Vitamin D, get them outside in the sunlight to play and exercise. Even if they’re ill, getting outside for sunlight will help.
  • As stated, children need exercise in the form of play. Do your best to keep them moving. Exercise with them!
  • Adding additional Vitamin C could prove helpful under the current circumstance and additional will not harm them.
  • Prevent germ spread. Washing hands regularly reduces stress on the immune system.
  • Avoid antibiotics unless absolutely necessary.
  • Serve more probiotic-rich foods. Fermented foods, plant-based unsweetened yogurts.

If your child is sick and medical staff has confirmed it’s just a typical childhood illness, keep the following in mind:

  • Toss the toothbrush or sanitize with hydrogen peroxide. Viruses can hop from toothbrush to toothbrush. If bacterial infection, it can reinfect.
  • Make sure to keep up their hydration.
  • If they have no appetite, this is the time to use apple juice cut with water and supplement protein. In the past, we’ve had great success supplementing pea protein into a green smoothie for our children when they’re sick. Their nutritional needs are far more important than contemplating the efficacy of using a protein supplement with a child.
  • If you can get them into the sunlight, that will help in many ways.
  • Whatever medication you choose is your call. I’m not an expert nor can I disseminate that information.

Everything above is non-medical precautions you can use prophylactically to keep your child’s immune system operating at peak performance.

What can you do to boost your immune system now?

Boost Your Immune System

The following suggestions are like adding paper money to your wallet. They have a larger effect on the immune system.

  1. If you smoke, quit.
  2. If you consume a lot of sugar, stop.
  3. If you eat a lot of prepackaged junk food, stop.
  4. Minimize alcohol consumption.
  5. If you have poor sleeping habits, put effort into better quality sleep.
  6. Make sure you get enough quality protein.
  7. Stay well hydrated.
  8. Make sure you’re getting enough of the micronutrients discussed above.
  9. Add mushrooms to your diet if you don’t already eat them.
  10. Based on the research specifically on COVID-19, I will go out on a limb and suggest megadosing Vitamin C.

Adding nutriceuticals or spices that “might” help is like adding loose change to your wallet. In other words, the list above will have a greater impact.


Yes, this is scary, but as you can see, there are many factors we can control that will have a large impact on improving our immune system.

Yes, social distancing is superior to all other things, but why not keep your immune system in peak performance!

I hope the above helps you stay safe and healthy going forward.

Boosing Immunity FAQs

What supplements boost immune system?

Again, a deficiency in any micronutrient will have a larger negative impact on your immune system than megadosing another micronutrient. But all else being equal, zinc, vitamin D and vitamin C have shown the most prolific effect on the immune system.

Can multivitamins boost immune system?

If you’re initially deficient in any one micronutrient, adding a multivitamin will bring your immune system up to par. Otherwise, it will not make a big difference.

Boost immune system to fight cold?

By eliminating sugar, alcohol, smoking and junk food, you can boost the immune system. In addition, getting adequate protein, adequate hydration, plenty of sleep and avoiding stress can help improve the immune system.

Will exercise help immune system?

It certainly will.

Can immune system be boosted?

It’s better to phrase it as “doing all the steps necessary to keep your immune system operating at peak.”

Research and References

[a] Myles, I.A. Fast food fever: reviewing the impacts of the Western diet on immunity. Nutr J 13, 61 (2014).

[b] Segerstrom, Suzanne C.,Miller, Gregory E. Psychological Stress and the Human Immune System: A Meta-Analytic Study of 30 Years of Inquiry, Psychological Bulletin, Vol 130(4), Jul 2004, 601-630

[c] Philip C. Calder and Samantha Kew, The immune system: a target for functional foods? British Journal of Nutrition, Volume 88, Issue S2, November 2002, pp. S165-S176.

[d] Lei Zhang, Yunhui Liu, Potential interventions for novel coronavirus in China: A systematic review, Journal of Medical Virology, 13 February 2020.

[e] Silvia Maggini, Eva S. Wintergerst, Stephen Beveridge, and Dietrich H. Hornig, Selected vitamins and trace elements support immune function by strengthening epithelial barriers and cellular and humoral immune responses, British Journal of Nutrition, Volume 98, Issue S1 October 2007, pp. S29-S35.

[f] Zunyou Wu, MD, PhD; Jennifer M. McGoogan, PhD, Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72 314 Cases From the Chinese Center for Disease Control and Prevention, JAMA. Published online February 24, 2020.

[g] David L Heymann & Nahoko Shindo, COVID-19: what is next for public health? The Lancet, Volume 395, Issue10224, P542-545, February 22, 2020.

[h] Bryant, P., Trinder, J. & Curtis, N. Sick and tired: does sleep have a vital role in the immune system?. Nat Rev Immunol 4, 457–467 (2004).

[i] Bente Klarlund Pedersen, and Laurie Hoffman-Goetz, Exercise and the Immune System: Regulation, Integration, and Adaptation, Physiological Reviews, Volume 80, Issue 3 July 2000, Pages 1055-1081.

[j] Peng Li, Yu-Long Yin, Defa Li, Sung Woo Kim, Amino acids and immune function, British Journal of Nutrition, Volume 98, Issue 2 August 2007, pp. 237-252.

[k] Kang J.X., Weylandt K.H. (2008) Modulation of Inflammatory Cytokines by Omega-3 Fatty Acids. In: Quinn P.J., Wang X. (eds) Lipids in Health and Disease. Subcellular Biochemistry, vol 49. Springer, Dordrecht.

[l] Cynthia Aranow, MDm Vitamin D and the Immune System, Journal of Investigative Medicine, Volume 59, Issue 6, 2011.

[m] Anitra C. Carr and Silvia Maggini, Vitamin C and Immune Function, Nutrients 2017, 9, 1211.

[n] Ward, R.J., Crichton, R.R., Taylor, D.L. et al. Iron and the immune system. J Neural Transm 118, 315–328 (2011).

[o] John R. Arthur, Roderick C. McKenzie, Geoffrey J. Beckett, Selenium in the Immune System, The Journal of Nutrition, Volume 133, Issue 5, May 2003, Pages 1457S–1459S.

[p] Jagetia, G.C., Aggarwal, B.B. “Spicing Up” of the Immune System by Curcumin. J Clin Immunol 27, 19–35 (2007)

How to Boost Your Immune System Now

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