Vitamin D and Your Immune System

Vitamin D and Your Immune System Without exception, every single cell in your body requires vitamin D to function properly, helping to keep your immune system strong. Unfortunately, most people are deficient in vitamin D, and it puts their health at greater risk for a number of problems beyond their bones. Vitamin D is best known for its role in calcium and bone metabolism, but emerging research indicates that low levels of vitamin D may be associated with increased risk of some cancers, type 2 diabetes, multiple sclerosis, cardiovascular disease, rheumatoid arthritis, depression, Alzheimer’s disease, infections, preeclampsia, cesarean deliveries and neurocognitive dysfunction. Do you exhibit any signs of a possible Vitamin D deficiency?
  • Fatigue
  • Depression
  • Muscle, bone, or back pain
  • Brain fog
  • GI trouble
  • Lowered immunity and slow wound healing
There are vitamin D receptor sites in each of your cells that act like catcher’s mitts. The way your hormones get into you is like a matching game — the estrogen hormone can only go into an estrogen receptor site. Testosterone goes into a testosterone receptor site. Thyroid hormone goes into a thyroid receptor site. They won’t go into other’s receptor sites. If there’s no receptor site for testosterone on your eyeball, testosterone has no effect on your eyeball. When the blood goes by there, testosterone in the blood just keeps going until it finds a catcher’s mitt to go into. There are two important substances for which there are receptor sites on every cell of your body, which means every cell needs these two critical substances. One is the thyroid hormone because the thyroid hormone is the thermostat that controls the temperature inside every cell. The other important receptor on every cell of your body is vitamin D. You don’t want OK levels of vitamin D — you want optimal levels of vitamin D. That’s approximately 50 to 75 nanograms per milliliter. Promising Research Suggests Vitamin D may be more effective than the Flu Vaccine Each year a new flu vaccine is formulated, and every time it’s a guessing game as to how effective it will be. Every year the Centers for Disease Control and Prevention (CDC) urges people (especially the most vulnerable in society) to get their flu vaccine. But how effective is it, and are there more effective treatments? Until the flu hits, it is hard to know whether that flu shot will be highly effective or completely miss its mark. It’s estimated that each year 5-20% of Americans catch the flu. The 2017-18 flu season saw its worst in four decades with approximately 80,000 deaths related to the flu. So, while influenza is common, it can have very serious consequences. People with low levels of vitamin D report significantly more colds and flu. Taking supplements can cut your risk of respiratory infections in HALF! In fact, for people who were deficient in vitamin D, boosting their levels had a significantly greater impact on flu prevention. One study showed that for that population, it was 10 times more effective taking supplementation than taking the flu vaccine. Vitamin D Levels Change Throughout the Seasons During the winter months your Vitamin D levels naturally plummet due to less sunlight hours. Vitamin D helps to keep your immune system strong, and it is needed during those difficult winter months. But even in summertime, for people who live further north, they may not be getting enough vitamin D during their sunlight hours. We also see more problems in the later seasons of life with getting the appropriate levels of vitamin D, which can be so critical for preventing respiratory illnesses, or minimizing injuries due to falls. This could be due to malabsorption problems, or they may take medications that block vitamin D from being fully utilized. Vitamin D Toxicity More often than not, we are worried about someone not getting enough vitamin D because it is so common. However, you can also have problems if you get too much. This does not happen through diet or sunlight. It is possible to get vitamin D toxicity if you take megadoses for extended periods of time when it is not needed. Symptoms of Vitamin D Toxicity
  • Nausea
  • Vomiting
  • Lack of appetite
  • Constipation
  • Weakness
  • Weight loss
  • Increased urination
  • Increased blood pressure
  • Cardiac arrhythmia
  • Palpitations
  • Kidney stones
Testing for Vitamin D Deficiency (or Toxicity) The two best times to take a Vitamin D Blood Spot Test is spring and summer. You may think, “Why would I need one in summer? That’s when it is sunny and people are out and about.” If you live in certain geographical areas, despite the beautiful weather, you may still not be getting enough vitamin D. Over the winter months, we lose a lot of sunlight hours and are outdoors less often typically as well. Taking a blood test in spring is a great indication of whether or not we are consistently getting enough Vitamin D. It is easy to test your levels. We mail you a “do-it-yourself” Vitamin D at Home Blood Test. You do a little finger prick to attain a small blood spot. That gets sent off to the lab. This is the only finger prick test that I know of that looks at all three markers of Vitamin D, instead of just one. 25-Hydroxyvitamin D Total – This is known for its role in bone health and calcium absorption. It also appears to affect immune function, neurodegenerative and cardiovascular issues, and other conditions. 25-Hydroxyvitamin D2 – This is the form obtained through vegetable diet sources. 25-Hydroxyvitamin D3 – This is obtained from animal diet sources and through sun exposure. Test to see if your levels are already low. This is a common deficiency, and one easily corrected through proper supplementation. GS Vitamin D3 Plus K2 Drops If you have a vitamin D deficiency, many people find the combination of vitamin D3 with K2 helps. Vitamin D helps your body to absorb calcium, and Vitamin K2 helps to direct it into the bones. They each offer their own benefits, as well as work in harmony with each other to get the job done. You can find both GS Vitamin D3 and GS Vitamin D3 + K2 on our website. GS Vitamin D3 + K2 is a soy-free, natural vitamin D3 and vitamin K2 in a water-soluble micellized form. Micellization greatly increases the solubility, absorption and bioavailability over oil or emulsified forms.
This formula includes the patented vitaMK7, a natural vitamin K2 (as MK7) which supports enhanced utilization of calcium in the bloodstream. VitaMK7® is shown in human clinical studies to increase osteocalcin (calcium-binding protein) levels, enhancing your body’s ability to utilize calcium in the bloodstream. It is also shown to prevent bone loss and promote bone integrity while significantly reducing the incidence of arterial calcification, promoting optimal cardiovascular function. An in-vitro study shows that vitaMK7® inhibits the production of PGE-2, a prostaglandin that acts as a potent stimulator of bone loss.
“What are optimal levels of vitamin D?”

A child’s immune system is fully developed between the ages of two and three. Then it’s really ready to go, and it’s working. We know that a vitamin D level between 50 and 75 nanograms per milliliter (ng/mL) is the ideal range to reduce the risk of developing autoimmune disease or arresting autoimmune disease.

Some doctors go higher than that, but I think 50 to 75 ng/mL is a safe zone to be in. While dosing is different for a child than an adult, the range of 50 – 75 ng/mL is the same level of concentration you are seeking in your body. It just takes a much smaller amount to reach that range for a child.

What are ways to increase vitamin D levels in the body?

There are three concepts here.

1. If you’re healing the gut, you need to take a capsule, so that it gets down to the gut for intestinal permeability. That’s why in our GS Support Packets, there are 22 different nutrients. It’s six pills in one pack, but it’s one pack a day. And its 22 nutrients all that are focused on healing intestinal permeability.

You have to stop throwing gasoline on the fire. You can’t keep eating Ding Dongs, and then take the GS Support Packets and think you’re going to be fine, right? You get all these different nutrients for that pleiotropic approach when you take the GS Support Packets. There are 5,000 units of vitamin D capsule in that pack. That’s the first way you get vitamin D.

2. The second way is the drops, and that’s called micellized vitamin D. The benefit of micellized is it is absorbed right in the mouth immediately. When you take micellized vitamin D, you increase your blood values five times higher than taking the same dosing with a capsule. If you want to get vitamin D to the gut, you take the capsule. If you want vitamin D to get throughout your entire body, you take the micellized vitamin D.

3. The third way is a little bit of exposure to the sun every day. Exposing your arms and legs to the sun for about 15 minutes helps tremendously in stimulating your body to produce vitamin D. Between 10:00 and 2:00 is great for where you live year round. Anywhere north of the imaginary line between San Francisco, CA and Atlanta, GA, doesn’t get enough vitamin D access from October to April.

Now, for those of you that are sun sensitive, there is an herbal product that we’ve begun to use; it’s called Sun Protect, and it’s with Sunhorse Energy. With Sun Protect, you take one capsule, and you don’t sunburn. It’s just remarkable what we’re seeing with that product. You can go out in the sun, get your 15 minutes of walking every day, and you won’t get red. You’ll know that you’re triggering vitamin D production, but you’re not getting the UVC damage that comes with sun.

Remember that while your body was not designed to hide indoors, you still need protection from overexposure. Odds are if you’re hiking, biking, swimming or camping, you do not stop after 15 minutes. So get added protection with sunscreen.

Those are the three ways that I’d recommend to help you get enough vitamin D.

Vitamin D plays an important part in the innate antimicrobial response. When your body does not get a sufficient (and appropriate) amount, implications for how your immune system functions suggests an increased susceptibility to infections and an increased risk for autoimmunity. Supplementing with Vitamin D is one of the simplest ways you can support your immune system, yet the benefits are far-reaching.

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Purple Lapacho

Purple Lapacho, a unique and potent herb, is valued for its potential to support overall well-being. Known for its immune-boosting properties, Purple Lapacho may help fortify the body’s natural defenses. This remarkable herb has also been associated with promoting healthy energy levels, supporting digestion, and fostering vitality.

Fo Ti

Fo Ti, a revered Chinese herb also known as He Shou Wu, is valued for its potential to support overall wellness. Traditionally used for promoting vitality and longevity, Fo Ti may contribute to maintaining healthy energy levels, cognitive function, and immune system performance. This remarkable herb has also been associated with supporting liver and kidney health, as well as fostering a sense of overall balance


Agave, a versatile desert plant native to the Americas, is recognized for its potential to support overall wellness. Rich in natural fibers and low-glycemic sweeteners, Agave may contribute to maintaining healthy blood sugar levels, digestive health, and providing a natural alternative to refined sugars.

Maral Root

Maral Root, a potent adaptogenic herb native to Siberia, is celebrated for its potential to contribute to overall well-being. Known for helping the body manage stress and maintain balance, Maral Root may also promote healthy energy levels, endurance, and cognitive function. This exceptional herb has been associated with supporting the immune system, fostering vitality, and enhancing physical performance.

  • Antioxidant and DNA Repair Stimulating Effect of Extracts from Transformed and Normal Roots of Rhaponticum carthamoides against Induced Oxidative Stress and DNA Damage in CHO Cells:


NotoGinseng, a distinct variety of Panax ginseng native to the Changbai Mountains, is esteemed for its potential to contribute to overall well-being. Renowned for its adaptogenic properties, Noto Ginseng may help the body manage stress and maintain balance. This exceptional herb has been linked to supporting cognitive function, promoting healthy energy levels, and boosting immune system performance.


Baicalin, a potent bioflavonoid derived from the Scutellaria baicalensis plant, is appreciated for its potential to promote overall wellness. With its antioxidant and anti-inflammatory properties, Baicalin may help protect cells from oxidative stress and maintain a balanced response to inflammation. This remarkable compound has been associated with supporting liver health, promoting cardiovascular function, and fostering a sense of vitality.

Coriolus Versicolor

Coriolus Versicolor, a remarkable mushroom, is esteemed for its potential to contribute to overall wellness. Known for its immune-supporting properties, Coriolus Versicolor may help strengthen the body’s natural defenses. This extraordinary mushroom has also been associated with promoting healthy energy levels, supporting digestion, and fostering vitality.


Ashwagandha, a revered adaptogenic herb, is acclaimed for its potential to support overall well-being. Known for helping the body manage stress and maintain balance, Ashwagandha may also contribute to healthy energy levels and mental clarity. This remarkable herb has been associated with promoting relaxation, supporting the immune system, and fostering vitality.

Gotu Kola

The main group of components in gotu kola is the triterpenes including asiaticoside, madecassoside, asiatic acid, and madecassic acid, which have antioxidant and anti-inflammatory properties that are shown to positively influence brain plasticity which means a much sharper you.

  • Exhibits significant wound healing ability, Improves microcirculatory parameters, Sedative and anxiolytic properties, Antidepressant, Re-vitalize the brain and nervous system, increase attention span and concentration and combat aging:


Guarana, a powerful plant, is celebrated for its potential to support overall wellness. Rich in natural caffeine, Guarana may help promote mental alertness, focus, and healthy energy levels. This remarkable plant has also been associated with supporting endurance and enhancing physical performance.


Catuaba, a potent herb, is appreciated for its potential to contribute to overall well-being. Known for its adaptogenic qualities, Catuaba may help the body cope with stress and maintain balance. This remarkable herb has also been associated with promoting mental alertness, healthy energy levels, and fostering a sense of vitality.

Reishi Mushroom

Reishi Mushroom, a highly-regarded fungus, is esteemed for its potential to enhance overall wellness. With adaptogenic properties, Reishi Mushroom may help the body manage stress and maintain balance. This extraordinary mushroom has also been linked to promoting immune system support, healthy energy levels, and fostering a sense of calm and relaxation.

Astragalus Root

Astragalus Root, a powerful herb, is respected for its potential to contribute to overall well-being. Renowned for its immune-supporting properties, Astragalus Root may help fortify the body’s natural defenses. Additionally, this remarkable root has been associated with promoting healthy energy levels, heart health, and supporting the body’s ability to adapt to stress.

Asian Licorice Root

Asian Licorice Root, a versatile herb, is valued for its potential to support overall wellness. Known for its adaptogenic properties, it may help the body cope with stress and maintain balance. This remarkable root has also been linked to promoting healthy digestion, respiratory function, and supporting the immune system.

American Ginseng

American Ginseng, a revered herb, is prized for its potential to contribute to overall well-being. With adaptogenic properties, it may assist the body in managing stress and maintaining harmony. American Ginseng has also been associated with promoting mental alertness, healthy energy levels, and supporting the immune system.

Rhodiola Rosea

Rhodiola Rosea, a robust herb, is admired for its potential to support overall wellness. As an adaptogen, Rhodiola Rosea may help the body cope with stress and maintain balance. This remarkable herb has been linked to promoting mental clarity, healthy energy levels, and increased endurance.

Peruvian Maca

Peruvian Maca, a nutrient-packed root, is celebrated for its potential to enhance overall well-being. Known for its adaptogenic qualities, Maca may help the body manage stress and maintain balance. This powerful root has also been associated with promoting healthy energy levels, endurance, and supporting hormonal balance.

Schisandra Fruit

Schisandra Fruit, a unique berry, is renowned for its potential to contribute to overall wellness. Boasting adaptogenic properties, it may help the body adapt to stress and maintain equilibrium. Schisandra Fruit has also been linked to promoting healthy energy levels, mental clarity, and supporting the body’s natural defense


Acai, a nutrient-dense berry, is recognized for its potential to enhance overall well-being. Rich in antioxidants, Acai may help support the body’s defenses against environmental stressors, while promoting healthy energy levels and vitality.

Himalayan Goji

Himalayan Goji, a nutrient-rich fruit, is valued for its potential contribution to overall wellness. This superfood is believed to support the immune system, promote healthy energy levels, and aid in maintaining balance within the body. With its antioxidant properties, Himalayan Goji may help protect cells from environmental stressors.

Holy Basil

Holy Basil has been found to protect organs and tissues against chemical stress from industrial pollutants and heavy metals, and physical stress from prolonged physical exertion. It has also been shown to counter metabolic stress through normalization of blood glucose, blood pressure and lipid levels.

Mikania Guaco

“Guaco” is Sun Horse Energy founder Dan Moriarty’s favorite herb, and the reason why he’s still alive. Traditionally, it’s a well-known herb for snake bites, scorpion stings and other venomous creatures. Guaco acts as a non-steroidal bronchodilator, meaning it opens up the airways without steroids. As a result of guaco opening up the airways, the alveoli (tiny air sacs in the lungs) are better able to accept oxygen transfer and get rid of carbon dioxide. In Brazil, Guaco syrup is one of the most popular herbal medicines used to treat the symptoms of asthmatic bronchitis, cough and hoarseness.

Pine Bark Extract

Many studies have shown that pine bark possesses anti-aging properties. It’s very similar in nature to the well-known antioxidant and anti-inflammatory compound, resveratrol, which is abundant in red wine and grapes. Pine bark has a proven beneficial effect on lipids, the cardiovascular and immune systems.

Osha Root

A traditional Native American herb, Osha is also known as “Bear Root”. Native Americans noticed that when bears emerged from hibernation, the first thing they did after being in a state of torpor for 4 months was not feast on salmon or drink water, but rather, dig up osha and eat it. Why? It decongests and wakes up the lungs. Native Americans who used Osha were able to run further, and treat their colds and congestion. Modern research studies suggest Osha may support the immune system by offering protective effects against oxidative damage.

I want to thank you for your existence. I want you to know that functional medicine has changed my life, well the life of my autistic son. So much so that I plan on taking the Functional Medicine Health Coach Certificate and work with my new friend who is now a Functional Medicine Doctor from the Institute of Functional Medicine and spread the word on GI testing and how finding the underlying issues will help eliminate autistic traits. 

I hope to be able to meet you one day so I can share this great news with others. Changing my son’s diet has changed him. Food is medicine!! By the way, I’m cooking my rutabaga. I’m Italian and never grew up with these. With love.

Rita Mastrangelo

I found you on YouTube a couple of weeks ago and I’m hooked. I listen to you a couple of hours every morning. I am being tested for celiac disease and have been gluten-free for a couple of weeks. Thank you for all of your insight.

April Renee

Just wanted to tell you that you’re amazing! You are helping so many people all over the world! Including me! Thank you so very much, Dr. Tom O’Bryan!

Patricia Puddle

Good morning Dr. Tom, Would just like to say thank you! This time last year I was going through a hell of a time with my gut. Terrible indigestion on a regular basis, feeling as if I had eaten a boulder and the tiredness was doing my heed (scottish for head) in! With two young girls being tired is not an option!

I went to the doctors on a number of occasions and they decided to prescribe omeprazole to mask the problem, sorry help my problem. I decided taking these drugs was not an option for me! So I started googling the life out of it!! Low and behold you started popping up!! Oh and Gluten intolerance! 

Your advice has been second to none! You have in my case really simplified what gluten does to my body and now that I have cut it out (which as it appears in lots of foods, some I can’t understand) I have found that my symptoms very quickly reduced and now I’m a year down the line they have gone for the vast majority of the time!! For that I’m truly grateful. I now follow you on YouTube and Instagram, which continues to educate me and the importance of gut health. I look forward to your future advice. Yours faithfully,

Gary Christie

Black Ant Extract

A Chinese medicine tonic, Black Ant is used to support energy levels. (In traditional Chinese medicine, Black Ant is given to increase vital Qi.) Research studies demonstrate that Black Ant supports the function of the thymus gland, which plays a crucial role in the immune system, producing and activating lymphocytes.

Siberian Ginseng

This well known adaptogen has been proven to reduce cardiovascular stress, lower and stabilize blood sugar to healthy levels, and encourages a more efficient lipid metabolism.

Green Tea Extract

Healthy energy producer and one of the more researched and promising supplements. It upregulates fat metabolism at rest and during exercise. In recent years the consumption of Green Tea Extract has shown to help prevent lifestyle diseases like cardiovascular disease because of it’s preventative effects on chronic inflammation.

  • Helps with weight loss by increasing a protein hormone which is involved in regulating glucose levels as well
    as fatty acid breakdown:
  • Decrease cholesterol absorption and plasma levels, has strong free radical-scavenging
    activity inhibiting LDL oxidation, reduce the adhesion molecule expression, has antitrombotic activities by inhibiting platelet aggregation: 


This is an enzyme/protein that speeds up biochemical reactions and helps to prevent and dissolve the formations of blood clots (thrombi); addresses the problem of blood hyperviscosity, thereby preventing thick and sticky blood, which is not conducive to overall cardiovascular health.

Water Hyssop

Best known as a neural tonic and memory enhancer this powerful herb increases cerebral blood flow and neurotransmitter modulation.


Referred to as the women’s ultimate power herb, by some herbal enthusiasts. Used in India for at least 3,000 years, Shatavari, is structurally similar to estrogen produced within the body. Some researchers have concluded shatavari can be a highly effective alternative to synthetic hormone replacement therapy for peri- and menopausal women.

Chaste Tree Berry

Improve female libido, mitigate PMS, reproductive health

Horny Goat Weed

Increase para-sympathetic nervous activity, mitigate osteoporosis, improve libido, enhance smooth muscle tissue function

  • Treatment for erectile problems and nerve injuries in human patients:
  • Prevents thickening or hardening of the arteries through multiple mechanisms, including attenuating DNA damage, correcting endothelial dysfunction, inhibiting the proliferation and migration of smooth muscle cells, repressing macrophage-derived foam cell formation and inflammatory responses, as well as preventing platelet activation:

Bulgarian Tribulus

Enhance athletic performance, improve circulation, improve sexual performance, more efficient rates of protein synthesis


Cordyceps, a genus of mushroom, gained lots of attention after Chinese long-distance runners performed impressively at international competitions in the 1990s and early 2000s. Along with high-altitude training, supplementing with cordyceps was part of their intense training program. A research study concludes that cordyceps improves tolerance to high-intensity exercise after supplementation with it because the fungus is thought to increase blood flow, enhance oxygen utilization; it also acts as an antioxidant. It also has powerful anti-tumor properties, the ability to regulate the endocrine system, enhance your immune function, and protect the kidneys, lung, liver, and other organs.

  • Immunomodulatory, antitumor, anti-inflammatory, and antioxidant activities, promotion of endurance capacity, and learning-memory improvement, can be used to treat conditions such as hyposexuality, night sweats, hyperglycemia, hyperlipidemia, asthenia, arrhythmias, and other heart, respiratory, renal and liver diseases:
  • Various pharmacological actions, including nephroprotective, hepatoprotective, anti-inflammatory, antioxidative, and antiapoptotic effects:

Ginkgo Biloba

In recent decades, an extract of the leaves of the tree Ginkgo biloba L. has been used to improve memory in disorders like Dementia disorders that affect memory and intellectual functioning, and are caused primarily by Alzheimer’s disease and vascular disorders.

  • Potent antioxidant properties and ability to enhance peripheral and cerebral circulation, ginkgo’s primary application lies in the treatment of cerebrovascular dysfunctions and peripheral vascular disorders:
  • Experimental results showed extracts of G.Biloba to upregulate protein expressions of BDNF:
  • The effects of Ginkgo biloba extract on cognitive functions in aged female rats;
  • The role of oxidative stress and brain-derived neurotrophic factor:

Lion's Mane

A very yummy and medicinal mushroom is a well established candidate for brain and nerve health because it triggers neurite outgrowth and regenerates damaged nerves. Lions Mane has been extensively studied for its neuro-health properties.


Jiaogulan, a versatile herb, is celebrated for its potential to support overall well-being. Known for its adaptogenic properties, Jiaogulan may help the body cope with stress and maintain balance. This remarkable herb has also been associated with promoting healthy energy levels, boosting endurance, and fostering a sense of calm and relaxation.