Prevention: What You CAN Do To Boost Your Immune System

...about 70% of the immune system in IN the gut, called GALT or gut-associated lymphoid tissue. GALT is a major player in the production of antibodies – the proteins responsible for identifying and neutralizing “invaders”.

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It’s All About the Terrain!

Time is of the essence! What can you do to build your immune system?  Well, believe it or not it’s not that difficult!  Many think that if they take GOBS of supplements then they will be healthy or have a strong immune system, yet their diet and lifestyle is far from optimal.

Bottom line is TERRAIN – your internal environment.  Build and maintain a beautiful terrain and very little can take hold and make you sick! Your best protection is a strong terrain!

There are three major factors that determine the overall strength of your terrain:  Diet, Gut Health and Hormone Balance


What’s the best diet to build the immune system?  Well, you might think it’s a lot of fruits and veggies, right? We know that fruits and veggies are full of vitamins and minerals that boost our immune system – Vitamin C, Vitamin A, Magnesium, Calcium. You’d be right to think this.  But most people don’t realize that protein is crucial to a robust immune system!  It has been shown that a diet deficient in protein impairs the immune system¹. We derive a huge amount of Vitamin D, Zinc, Vitamin A from animal protein sources that act to build, nurture and regulate our immune system.  Lectin and phytic acid found in plant proteins are anti-nutrients and prevent absorption of nutrients in the gut and some are relatively high in pro-inflammatory Omega-6 fatty acids. Anything that makes you MORE inflamed makes you MORE susceptible to disease!

But the quality of animal protein matters! It must be grass-fed, grass-finished, wild game, wild caught, pasture-raised to be considered “quality”. Organic is a strong preference as well. Then you are loading up on Omega 3 fatty acids – these are ANTI-inflammatory.

Recommendation:  Eat a diet rich in colorful veggies, fat, animal protein and fruit.  Some need more carbs than can be found in veggies and fruit, so I often suggest adding organic, USA-grown white rice or skinned, organic white potatoes as tolerated and/or needed for fuel.  Some need more protein than others – especially if your exercise is heavy weightlifting.  But EVERYONE needs fat!  I’m very supportive of REAL fats – particularly animal fats (such as quality pork lard, beef tallow, duck fat, etc) but also find immense value in coconut oil, butter/ghee, avocado oil.  But remember – quality matters!!


Why is the gut so important in immune system function? Well, to start, about 70% of the immune system is IN the gut – called GALT – or gut-associated lymphoid tissue. GALT is a major player in the production of antibodies – the proteins responsible for identifying and neutralizing “invaders”.

Also, the gut microbiome or “gut bugs” (micro-organisms made up of bacteria, fungi, and others) have been shown to play a huge role in immunity as well². How cool is that? Something from outside of ourselves, micro-organisms that live in and on our bodies protect us and fight off “invaders” for us! Our own army!

So many don’t even realize that they have gut “issues”. Maybe you (or your family) consider yourself “gassy”. Doesn’t everyone fart???  Or you might be so used to skipping days in the bathroom or maybe the opposite and make many daily trips to the bathroom.  While most seem to consider these things to be normal – THEY ARE NOT!  It is not NORMAL to be gassy! It’s not NORMAL to be constipated. It’s not NORMAL to have many bowel movements in a day! All too often we confuse “common” with “normal”. Just because it’s COMMON doesn’t make it NORMAL!

Recommendation:  Work on gut health with diet first! Make sure you are eating a nutrient-dense diet. Don’t jump to supplementation first. You CANNOT supplement a body to health – especially if other factors like diet are ignored!  But if your gut is weak – you need to better understand what’s wrong! I strongly recommend the Biome FX Test to understand your microbiome better – where it goes right and where it goes wrong. THEN you can better support it with supplements. Check out the BiomeFx test HERE!

Just throwing supplements at an over-burdened body will ONLY burden it further!


Hormone balance is a loaded term – it’s multi-faceted. Hormones such as estrogens and cortisol are very interconnected to gut health and immunity.  You cannot fix one without fixing the other.

Numerous studies have shown the relationship of estrogen levels on immunity, particularly autoimmunity³. Normally, estrogen is broken down in several steps, recirculated if needed and removed from the body if not.  When done efficiently you have estrogen balance. With poor elimination of estrogen and its metabolites, you can be more prone to immune dysfunction that can manifest as autoimmune flares, cancer, PMS, etc.

The relationship of estrogen and the gut is strong.  For example, the estrobolome – a specific microbiome dedicated to clearing out estrogens from your body is in the gut. When it works perfectly it’s a beautiful thing as it clears the right amount of estrogen from the body. But it doesn’t always do the job properly and can result in too low or too high of estrogen.

Cortisol (a major stress hormone) is directly related to immunity. It can act as an “off switch” to the immune system. High and low cortisol can alter the body’s appropriate response to an immune threat. In times of high stress/high cortisol we often see less immune response – acting more as a suppressor of the immune system – preventing or dampening the immune response. But when that time of high stress/high cortisol passes – by removal of stress or adrenal fatigue – the immune response can kick into high gear as inflammation is no longer suppressed and you have a more dramatic immune response.

Recommendation:  Learn what your hormones are saying to you! My absolute favorite hormone test is the DUTCH test. It is incredibly informative and provides so much value when you are on a fact-finding mission! Not only does it test sex hormones and metabolites (estrogen, progesterone, testosterone, DHEA) but adrenal/stress hormones as well as some other valuable tests! Big bang for your medical buck!  Check out more about the DUTCH Test HERE!

 But let’s be honest – you can’t just supplement your way to a good immune system, so I NEVER recommend taking a bunch of “stuff” without doing the important work behind the scenes! So, focus on the terrain FIRST!

BUT there are supportive protocols to boost your immune system during these times!  Below I discuss some of my favorite nutrients to take and I have added natural food sources and my favorite brand recommendations HERE


Vitamin D3 is one of my absolute favorite supplements for just about everything. The reason is that it is extremely rare to test someone with normal levels (normal to me is 70ng/ml)– so pretty much everyone is low. And vitamin D deficiency is linked to everything from Multiple Sclerosis to Cancer to the Common Cold.  But vitamin D deficiency has also been linked to obesity, diabetes and clotting issues – all shown to be big risk factors for contracting Covid and a higher mortality rate for those that have Covid.

Best way to get it is from the sun on our skin.  But people have grown terrified of sun exposure! Instead of getting a healthy dose of sunlight on our skin to make that beautiful vitamin D many slather sunscreen all over their bodies, wear long sleeves and avoid sunshine like the plague!  If sunshine on our skin helps create vitamin D which is crucial to every part of our body, how can it be bad, right??!!  SUNSHINE ON THE SKIN IS NOT BAD! However, burning is bad! Use common sense!

A study published in April 2021 found those with vitamin D deficiency were an almost FIVE times more likely to get Covid – a significant increased risk for contracting Covid4 and an uber simple fix is to make sure your vitamin D levels are up to par.

Also, Covid is marked by a significant increase in inflammatory cytokines – small protein cell-signalers. A low level of Vitamin D is also connected to an increase in inflammatory cytokines and an increased risk of viral upper respiratory tract infections5.

Big connection here, folks!

Food Sources:  Wild-caught fish, beef liver, egg yolks, dairy

Recommendation:  Get out in the sun, eat foods high in D3 and take my favorite brand of Vitamin D3 – a liquid that is highly absorbable and contains some K2 as well – FIND IT HERE.  And you need way more than 600iu daily to get and maintain those levels near 70ng/ml!


Zinc has long been a supportive nutrient against the common cold – in essence it prevents cold viruses from sitting on their receptors therefore preventing colds and/or shortening the duration/severity.

Zinc has also shown to have great promise in preventing and treating Covid6. Zinc blocks important enzymes that are responsible for viral replication therefore having a possible role in prevention, decreasing duration and severity of Covid.  BUT it must get INTO the cells! Therefore, using a zinc ionophore (a substance that transports ions like zinc across cell membranes) has been deemed crucial.

Risk factors of low zinc levels are quite like vitamin D deficiency – many of those with co-existing conditions such as chronic disease, tend to have zinc deficiencies – making them predisposed to contracting Covid or suffering more severely if they do get it.

It has been suggested for use with Hydroxychloroquine (HCQ) and Azithromycin in the Zelenko protocol in which HCQ acts as both a zinc ionophore as well as inhibiting inflammatory cytokine production (prevalent in Covid).  Zinc has also been used in tandem with Quercitin (an over-the-counter zinc ionophore) to successfully prevent and treat many cases without the use of medications.

Word of warning:  Long-term zinc supplementation can cause copper deficiency and may interfere with absorption of some medications. While higher doses during Covid are likely more effective – you don’t want to stay on daily Zinc supplements forever. And many physician-grade brands will contain copper to prevent you from off-setting that delicate balance.

Food Sources:  Red meat, shellfish, legumes, seeds, dairy, eggs

Recommendation: A few fantastic companies have come up with blends of Covid immune boosting nutrients. My fav contains both the quercitin and zinc and other ionophores – FIND IT HERE!


Quercitin is a useful nutrient for so many reasons – a power antioxidant, anti-cancer, promotes heart health and fights allergies. But in the prevention and treatment of Covid it acts as a natural zinc ionophore (as described above).   Since HCQ has been banned in most states during Covid – many have been using Quercitin in place of it to naturally transport zinc into the cells.

Food Sources:  Garlic, onions, kale, blueberries, broccoli

Recommendation:  As stated in the Zinc section – a few fantastic companies have come up with blends of Covid immune boosting nutrients and my fav contains both – FIND IT HERE!


I think we can all appreciate that vitamin C is “king” when it comes to cold and flu season.  And it’s no different with Covid. It’s a super powerful antioxidant not to mention supportive in collagen production, prevention of sunburns, as well as boosting immunity!

In studies, vitamin C has been shown to reduce the risk of contracting viruses as well as lessen the severity and well as duration of viruses7. But a new study shows that is also might reduce ICU stays for those hospitalized with Covid.8 That’s huge!

There have been protocols in place for decades for use in prevention and treatment of viral upper respiratory infections using 2000+mg/day. Given that Covid can be a “stronger” virus than the standard cold or flu it is often recommended that the dose be increased to at least 3000mg daily (divide your dose to avoid diarrhea).

Food Sources:  Acerola cherries, rose hips, yellow bell peppers, parsley, kale, broccoli, brussel sprouts, lemons, oranges

Recommendation:  Liposomal Vitamin C is superior to other forms because it has much higher bioavailability – it’s absorbed into the body and cells much better. My favorite brand is HERE.  Just make sure to divide your doses even with liposomal so it doesn’t cause diarrhea!


Previously, we discussed gut health and the fact that at least 70% of the immune system is in the gut. However, probiotics are proving to be VERY beneficial to protect against multiple diseases outside of the gut by “reinforcing immunity” and restoring balance within the gut microbiome.9 Changes in the microbiome result in changes in the immune system – both positive and negative.

While many turn to dairy, such as yogurt, for their probiotics I have to say I’m not the biggest fan of conventional, store-bought yogurt.  It’s simply not cultured long enough to make a big impact. 

Food Sources:  Fermented food, cultured food

Recommendation:  I have one brand of probiotic I recommend to clients found HERE but I also recommend testing your microbiome using the BiomeFX test (HERE) to see what’s out of balance and can be corrected!  When it comes to the gut – more information is KEY!


Garlic is known to be one of the most potent antimicrobials out there.  The main component in garlic contributing to its great power is allicin – a organosulfur compound created once the garlic is chopped or crushed.  Allicin must be in a stabilized form to give you the most potentized and useful version and many companies do not stabilize it.

Garlic has many benefits:  acts by blocking entry of a virus into a cell, inhibits viral replication but enhances the immune response so acts strongly in prevention of illnesses9.  Garlic is actively being studied as a great option in prevention and treatment of Covid due to its ability to inhibit a main enzyme in SARS-CoV2 that is responsible for its rapid replication.11 It’s definitely one of the most important supplements I have carried with me pretty much everywhere I have traveled in the world – just in case!

During cold and flu season I have suggested to clients to take 1 cap/day to prevent illness – more if exposed.  On occasion – those super sensitive or flat-out allergic to sulfur drugs have had a minor reaction to garlic supplements.  Be careful using if you are one of those people!

Food Sources:  Garlic

Recommendation:  While I support eating garlic (as long as you have no known sensitivities to it) you simply cannot eat enough daily to have a consistently strong immune response as you can get by taking my favorite stabilized allicin product HERE!

REMEMBER – Balance is everything!

Keep your primary focus on your terrain to make sure you mount the appropriate immune response in all situations.  You simply cannot rely on taking every supplement on the market to keep you “healthy”.  But during these times it doesn’t hurt to have a few supplement “tools” around to add an extra layer to your immune system!!  Once again HERE is my list of favorites!

Stay Happy and Healthy!!

Dr. Kelley


  1. Peng LiYu-Long YinDefa LiSung Woo KimGuoyao Wu. 2007. Amino Acids and Immune Function. Br J Nutr. Aug;98(2):237-52.
  2. Fields, H. 2015. The Gut: The Bacteria and the Immune System Meet.
  3. Khan D, Cowan C, Ansar Ahmed S. Estrogen and signaling in the cells of immune system. Adv Neuroimm Biol(2012) 3(1):73–93
  4. Katz et al. 2021. Increased risk for COVID-19 in patients with vitamin D deficiency. Nutrition Apr;84:111106.
  1. Weir, et al.   Does Vitamin D deficiency increase the severity of Covid 19? Clin Med (Lond)., Jul; 20(4): e107–e108.
  2. Arentz et al.   Zinc for the prevention and treatment of SARS-CoV-2 and other acute viral respiratory infections: a rapid review  Adv Integr Med., Dec; 7(4): 252–260
  3. Karlowski TR, Chalmers TC, Frenkel LD, et al. 1975. Ascorbic acid for the common cold: A prophylactic and therapeutic trial. JAMA, 231:1038-1042.
  4. Hemilä H, Chalker E. Vitamin C can shorten the length of stay in the ICU: a meta-analysis. Nutrients, 11:708
  5. Rouf et al. 2020. Antiviral potential of garlic (Allium sativum) and its organosulfur compounds: A systematic update of pre-clinical and clinical data.
    Trends Food Sci Technol., Oct;104:219-234
  6. Shabazi et al.   Probiotics in the treatment of viral respiratory infections and neuroinflammatory disroders.  Molecules, Oct 22;25(21):4891
  7. Khubber, et al.   Garlic (Allium sativum L.):  a potential unique therapeutic food rich in organosulfur and flavonoid compounds to fight with Covid-19.  Nutr J, Nov 18;19(1):124

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