Strategies to Support the Immune System

Strategies to Support the Immune System: Nothing to Sneeze At

By George Gillson MD PhD CCFP

In the 17th century, for some obscure reason, sneezing came to be seen as a way to show disapproval, disinterest and boredom. I certainly hope none of you begin sneezing as you read this post and I also hope that you don’t do much sneezing this winter as a result of reading this post!

September, sitting at the edge of the cold and flu season, seems like a great month to talk about supporting the immune system. In this post I’ll discuss the biochemical approach, including hormones, basic nutrients, and other more complex supplement formulas; in the next post I’ll step back and look at immune support from a different angle.

Given the ready availability of antibiotics, antiviral drugs, and vaccines, it’s easy to forget about the basics. The Earth’s population has increased dramatically since we humans started staggering around on it and we tend to think that’s mostly because of medical advances. In reality, there are more of us around mostly due to increased availability of cleaner water, better food, more education and less poverty.

Our immune systems are pretty darned good at keeping us healthy when we are getting enough sleep, getting some sun on our skin when we can, maintaining a healthy weight, eating a wide range of different-colored foods and being physically active. (Note that too much exercise is a great way to tank your immune system.  You’ll know you’re overdoing it when you start getting one cold after another.)

However, keeping all these good lifestyle habits is easier said than done. Throw work and home stress into the picture along with difficult-to-avoid environmental insults (organic and inorganic pollutants) and you wind up with an immune system that isn’t in top shape. We struggle with colds and bronchitis through the winter and often reach for an antibiotic at the first sign of trouble; some of us might place all our faith in vaccines and forget to also “tend the garden” as it were.

Long story short, most of us probably need some immune system support for day to day living and there are things we can also do acutely if we are “coming down with something”.

  1. Sermon over.

Briefly, there are two aspects to the immune system: the non-specific, inherited, ancient “first response” or Innate system, and the specific, learned, “SWAT team” or Adaptive system.  I’m not going to get into the details about innate/adaptive immune responses as this is a blog post, not a book. Either way, we’re talking about specialized cells and specialized biochemistry needed when we are attacked by a bacteria, a virus or a parasite.

Innate adaptive immune responses

Feeding Your Immune System

The mucous layer of the tissues lining our airways and gut is the first line of defense, helping to trap and destroy invaders. One classic vitamin formulation that can support this perimeter is “ACES plus Zinc” composed of Vitamins A, C, E along with the elements selenium and zinc. Let me break down the logic of that a wee bit and throw some more letters in the ring for possible inclusion in the acronym.

Vitamin A has many other roles* but one of its key actions is to support the mucous barrier. Vitamin C promotes collagen formation and helps support structural integrity of the cells lining the airways and gut. The Vitamin E family of molecules can help to quench free radicals that might damage cell membranes in the defensive perimeter. Selenium supports the synthesis of glutathione which is another scavenger of free radicals. Zinc is necessary to make the binding protein that squires Vitamin A around the body and facilitates its delivery to tissues.

Vitamin A Myth: Many people believe that humans can efficiently make Vitamin A from beta-carotene. Many people lack the enzyme needed to convert the beta-carotene found in carrots, spinach, sweet potatoes and those flat, orange, marshmallowy pumpkin candy things that appear at Hallowe’en, into Vitamin A. This isn’t true. There is no beta-carotene in the candy things. Seriously, you get Vitamin A mostly from animal foods. This article has a good discussion of why many people are deficient in Vitamin A and the best ways to fix it (Most of us should supplement Vitamin A).

There are several other letters that could be added to the ACES list: P, D, NAC and G. Don’t try to make a new acronym. I couldn’t do it.

P is for Pantothenic acid (Vitamin B5) which is finally getting the respect it deserves for the important role it plays in immune responses; see Gheita et al for a 2020 review on Vitamin B5 (Gheita 2020).

D is for Vitamin D (duh) but any reasonable treatment of Vitamin D’s key role in immune function would also be a book in its own right. Ismailova and White discuss the role that Vitamin D has long been known to take in fighting bacterial infections and, more recently, viral infections including SARS CoV 2 (Ismailova 2022). Kumar et al point out the association between Vitamin D deficiency and severe SARS CoV 2 infection and discuss the role of high-dose Vitamin D therapy in these cases. (Kumar 2021). The hyperlinked text will take you to downloadable versions of the papers.

N-acetyl cysteine, aka NAC, is a direct precursor of the free radical scavenger, glutathione, and so contributes to limiting damage at the site of infection.

*Vitamin A has many other complicated, beneficial effects on all aspects of the immune response (Huang 2018). Here’s a link directly to an article by Gheita et al for those who want to know more about Vitamin A:

I consider all of the above to be sort of a “base layer” of supplements needed to promote healthy immune system functioning. An example of a good base layer formulation is shown below. Note that Vitamin D almost always needs to be dosed separately to get enough on board. You need to consult with your Integrative/Restorative Medicine practitioner for advice on dosing and formulations for basic nutrients and vitamins.


The Hormonal Influence

Another basic aspect to improving and maintaining immune function is hormone balance with particular emphasis on testosterone, DHEA, cortisol and estrogens, as well as thyroid hormone. There is a natural bias in immune response between males and females, with females having better immunity against viruses and better antibody responses to vaccination. The flip side of this is that females have a greater tendency to develop autoimmune diseases such as Rheumatoid Arthritis (Taneja 2018). After menopause, maintenance of healthy estradiol levels is important for immune function in women.  Similarly, maintenance of adequate testosterone in aging makes is also important. For example, Lanser et al discuss the finding that males with low testosterone are at increased risk of more severe COVID-19 disease (Lanser 2021). DHEA in the appropriate dose, can help to support both testosterone and estrogens.

Two other important hormones are cortisol and thyroid hormone. Cortisol is anti-inflammatory and helps keep the immune system from running rampant. If cortisol is too high for too long, the immune system escapes the regulating effect of cortisol and this can result in chronic inflammation. The same thing can occur if cortisol production is too low and this can be associated with too little thyroid hormone. Therefore, it’s important to make sure that cortisol and thyroid hormone levels are adequate, when considering the immune system. You need to work with an experienced Restorative/Integrative Medicine practitioner who can help you balance your sex hormones, cortisol and thyroid hormones with appropriate blood, saliva and urine hormone tests and appropriate interventions including hormone supplementation when necessary. In some cases, counselling may also be useful to regulate cortisol for individuals dealing with ongoing life stresses or trying to recover from previous traumatic experiences.

Supplementing the System

Along with hormones, basic vitamins and nutritionally-relevant chemical elements, there are many supplements that are used seasonally or acutely to prevent illness or nip infections in the bud. These include plant formulations such as Astragalus, Elderberry extract, Andrographis, Echinacea, Garlic extract, Green Tea extract, Shiitake, Maitake, Reishi, and Cordyceps mushrooms. Immune-supporting formulas usually consist of synergistic blends of multiple ingredients and the ones I’ve listed show up regularly.

Garlic is a particular favorite of mine and it has been studied extensively for its anti-inflammatory, cardioprotective and immune-modulating actions. You can download a review article on garlic by Arreola et al here:

As our understanding of how the immune system works has evolved, so has our understanding of how traditional remedies exert their time-tested influence. A complete discussion is well beyond the scope of this article, but mechanisms include direct virus- and bacteria-killing effects, blocking the ability of viruses to penetrate cells as well as effects on the cells and signaling cascades operating in the immune system. Some agents stimulate or support the thymus and spleen. Mushrooms also exert the same kinds of effects but wield their own unique Immunomodulatory molecules which are complexes of various sugars not found in plants.

Here is a suite of products favored by practitioners at our clinic, although every practitioner has their own list of go-to products determined by their own experiences with patients.  There is no one best solution for any individual.

Natural Products

I wish I had more space here to talk about the huge strides that have been taken to understand how these natural products, discovered by careful observation over thousands of years, support our physiology.  The more we learn, the more we appreciate how complex our physiology is. In the next post I’ll move away from strictly biochemical approach and look at how the ancient practice of Traditional Chinese Medicine (TCM) can also help support your immune system.

George Gillson MD PhD

Author: George Gillson, MD, PHD, CCFP
EvolveWell Medical Director


 Arreola R, Quintero-Fabián S, López-Roa RI, Flores-Gutiérrez EO, Reyes-Grajeda JP, Carrera-Quintanar L, Ortuño-Sahagún D. Immunomodulation and anti-inflammatory effects of garlic compounds. J Immunol Res. 2015;2015:401630. doi: 10.1155/2015/401630. Epub 2015 Apr 19. PMID: 25961060; PMCID: PMC4417560.

Dai Y, Chen SR, Chai L, Zhao J, Wang Y, Wang Y. Overview of pharmacological activities of Andrographis paniculata and its major compound andrographolide. Crit Rev Food Sci Nutr. 2019;59(sup1):S17-S29. doi: 10.1080/10408398.2018.1501657. Epub 2018 Sep 10. PMID: 30040451.

Gheita AA, Gheita TA, Kenawy SA. The potential role of B5: A stitch in time and switch in cytokine. Phytother Res. 2020 Feb;34(2):306-314. doi: 10.1002/ptr.6537. Epub 2019 Nov 5. PMID: 31691401.

Huang Z, Liu Y, Qi G et al. Role of Vitamin A in the Immune System. J Clin Med. 2018 Sep 6;7(9):258. doi: 10.3390/jcm7090258. PMID: 30200565; PMCID: PMC6162863.

Ismailova A, White JH. Vitamin D, infections and immunity. Rev Endocr Metab Disord. 2022 Apr;23(2):265-277. doi: 10.1007/s11154-021-09679-5. Epub 2021 Jul 29. PMID: 34322844; PMCID: PMC8318777.

Kumar R, Rathi H, Haq A et al. Putative roles of vitamin D in modulating immune response and immunopathology associated with COVID-19. Virus Res. 2021 Jan 15;292:198235. doi: 10.1016/j.virusres.2020.198235. Epub 2020 Nov 21. PMID: 33232783; PMCID: PMC7680047.

Lanser L, Burkert FR, Thommes L et al. Testosterone Deficiency Is a Risk Factor for Severe COVID-19. Front Endocrinol (Lausanne). 2021 Jun 18;12:694083. doi: 10.3389/fendo.2021.694083. PMID: 34226825; PMCID: PMC8253686.

Taneja V. Sex Hormones Determine Immune Response. Front Immunol. 2018 Aug 27;9:1931. doi: 10.3389/fimmu.2018.01931. PMID: 30210492; PMCID: PMC6119719.