In the midst of the COVID-19 pandemic, we’ve received some questions from our community about what to do differently if you have an overactive or underactive immune system. First, I think it’s best to take a step back and ask, “How do you know you have an overactive or underactive immune system?”

There are some situations that have a high likelihood of immune disruption, but many other situations are grey areas. As always in functional medicine, it’s better to test than guess!

This article will cover some immunity blood tests that we offer that will help you better understand your immune system.


Let’s look at immunity in a broad sense. When you are fighting a new infection, your immune system should be working it! This is a healthy response. This is different than a cytokine storm, which I discuss later. An underactive immune system usually occurs after the immune system has pooped out after a longstanding infection or sometimes after medication.

We run a comprehensive blood test, and it includes a detailed thyroid panel, a red blood cell analysis, a white blood cell analysis, a vitamin D test, and some blood sugar tests, and much more. This is a complete overview of your health functionality.

Before COVID-19, we were mainly using the WBC (white blood cell) panel to suggest gut infections or autoimmunity.

If I see a high number, then the immune system is fighting something. A low number suggests the fight has gone on too long. This is a general assessment; we’ll dig into WBC differentials later.



The factors that affect respiratory immunity are:

  • Anemia
  • Prediabetes or diabetes
  • Low vitamin D
  • Low or high WBC
  • Low or high lymphocytes

Beyond that, we can get suggestions about parasites, autoimmunity, and a definitive look at Hashimoto’s thyroiditis status and hypothyroidism.


“Immunodeficiency disorders may affect any part of the immune system. Most often, these conditions occur when special white blood cells called T or B lymphocytes (or both) do not function normally or your body does not produce enough antibodies.” (1)

Your white blood cells include a number of cell types. We’ll look at the total WBC count, then we’ll explore WBC types.


The is the total number of white blood cells. The ideal functional range is between 5k-7.5k per microliter. Heightened WBCs in pregnancy is normal at 6k- 17K.


Reasons for a low WBC count include:

  • Cancer
  • Chemotherapy
  • Radiation
  • Chemical exposure affecting bone marrow
  • Lupus
  • Rheumatoid arthritis
  • Viruses
  • Blood infections
  • HIV
  • Antibiotics
  • Corticosteroids
  • Alcoholism
  • Anemia (2)
  • Nutrient deficiencies
  • Spleen infected or removed
  • Toxic mold/CIRS (3)
  • Hypothyroidism


“Immature lymphocytes leave the bone marrow and find their way to the thymus where they are “educated” to become mature T-lymphocytes.” (4)

I’m going to put the most focus on lymphocytes, as they are instrumental in protecting you from things like early COVID-19 exposure. Lymphocytes include cells like T cells, B cells, and Natural Killer (NK) cells.

Disclaimer: I am not stating this testing is a way to prevent, identify or treat COVID-19! This blog is meant to educate you about your immune system only.

WBC types are measured in percentage of the total and absolute amount. I used to only look at the percentage, and I think that’s fine if the amount of WBC is normal, but for the purpose of this research, I am looking at absolute amounts too.

The ideal functional range for lymphocytes is 24%, and 44% and the absolute range is 1.1 – 3.4 × 109/L.

Reasons for low lymphocyte count are pretty similar to reasons for low WBC count, although I did notice “heart conditions,” “recent illness,” and “connective tissue disorders such as Ehlers-Danlos and Marfan Syndrome” as well. (5)

Low lymphocytes under 1.1 are associated with increased mortality. For example, low lymphocytes and high monocytes (you’ll learn about these next) indicated poor prognosis in gastric cancer in a 2018 study published by the BMC Gastroenterology journal. (6, 7)

You can also get a breakdown of types of lymphocytes, and this is called a lymphocyte subset panel test. This is often used to identify HIV. We do not include this in our standard testing.


Since I brought them up earlier, let’s talk about monocytes next. Monocytes are killers:  phagocytic cells that develop into macrophages when they migrate into tissues.

Phagocytic means they engulf and consume foreign material and debris. (8)

The normal range for monocytes is 0-7% or under 0.8 × 109/L. High monocytes can indicate cancers, autoimmune disorders, cytokine therapy, and chronic infections. (9) Cytokine therapy is the administration of a cytokine, Interleukin-2 (IL-2), to stimulate lymphocyte production against cancerous tumors. (10)

Monocytes, Neutrophils, Eosinophils, Basophils

Initially, I detailed these remaining WBC types, but I thought it got a little dull for the reader (you!)

So I’ll just summarize to say that these remaining WBC types are suggestive of:

  • Parasites
  • Toxicity
  • Allergies
  • Autoimmunity
  • Immuno-suppressive drugs


I’ve heard some rumors that vitamin D could be bad for COVID-19. While I don’t think you should take sensational amounts without testing, I believe most people need 5,000 IU daily in the winter just to stay even.

A large 2017 study concluded, “Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall.” (11) Isn’t that what we all want right about now?

Vitamin D plays a critical role in regulating the immune system. Vitamin D deficiency is associated with an increased risk of autoimmunity and supplementation with vitamin D may benefit people with autoimmune diseases.

An ideal functional lab level of vitamin D3 is around 80 nmol/L. Many of our clients are severely vitamin D deficient, even with supplementation. You may not get outside enough, and when there are winter rays or you have internal inflammation, it can mean you aren’t absorbing much D.

Again, the only way to know is to test, and we’ll advise you on the right amount of vitamin D based on your results.


Anemia is a very unsexy topic, but it can really take you down! As you age, lower stomach acid production can mean you aren’t breaking down your food as well and thus not absorbing enough nutrition.

If you become anemic, you can become short of breath, tired, and have weakened immunity. This can be confused with COVID-19, and can also leave you more susceptible. 

There are actually many types of anemia. For this blog, I am going to focus on anemias due to micronutrient deficiency that can lead to weakened immunity.

Populations that may be prone to anemia include:

  • Pregnant women
  • Endurance athletes
  • Vegetarians
  • Women with heavy periods (12)
  • The Elderly
  • Those with chronic digestive issues
  • Those with heavy metal or other toxicity
  • Those with hypothyroidism

Iron Deficiency Anemia

Iron deficiency can cause reduced T cell proliferation. (13)

Signs and symptoms of iron deficiency may include:

  1. Fatigue
  2. Pale skin
  3. Frequent infections
  4. Swollen tongue
  5. Restless leg syndrome
  6. Pica
  7. Hair Loss (14)

B12 Deficiency Anemia

B12 plays an important role in white blood cell production, and white blood cells are essential for proper immune system functioning.” (15)

B12 also modulates immunity, “especially relating to CD8+ cells and the NK cell system.” (16)

Folate (B9) Deficiency Anemia

Folate deficiency also lowers immunity, negatively affecting cell-mediated immunity and antibody production and function. (17, 18)

A January 2020 review in the journal Nutrients concluded:

It has since been established that the complex, integrated immune system needs multiple specific micronutrients, including vitamins A, D, C, E, B6, and B12, folate, zinc, iron, copper, and selenium, which play vital, often synergistic roles at every stage of the immune response….daily micronutrient intakes necessary to support immune function may be higher than current recommended dietary allowances. (19)

Nutrient deficiencies may be associated with a leaky gut diagnosis.

The more I study the immune system, I realize how just about everything supports it!  It’s such a good reason to support overall health on many fronts. As far as the micronutrients above.


Side Note About COVID19

Serious or fatal cases of COVID-19 favor smokers, diabetics and hypertensive patients. Certain cell receptors present in certain organs such as the lung and heart, called ACE2 receptors, are targeted by COVID-19.

“ACE2 has been shown to be a co-receptor for viral entry for SARS-CoV-2 with increasing evidence that it has a protracted role in the pathogenesis of COVID-19. ACE2 has a broad expression pattern in the human body with strong expression noted in the gastrointestinal system, heart, and kidney with more recent data identifying expression of ACE2 in type II alveolar cells in the lungs.” (20)

This has caused some concern over medications these patients are on that may make them more susceptible to COVID-19. This article concludes that, “there is insufficient clinical or scientific evidence to determine how to appropriately manage hypertension in the setting of COVID-19.”

Similarly, there has been concern that some herbs or supplements that modulate immune function could induce a cytokine storm. ‘Cytokine storm’ is a term that was coined in 1993 and has been associated with a number of diseases and viruses.

The cytokine storm (hypercytokinemia) is the systemic expression of a healthy and vigorous immune system resulting in the release of more than 150 known inflammatory mediators (cytokines, oxygen free radicals, and coagulation factors).

Normally, this feedback loop is kept in check by the body. However, in some instances, the reaction becomes uncontrolled, and too many immune cells are activated in a single place. The precise reason for this is not entirely understood but may be caused by an exaggerated response when the immune system encounters a new and highly pathogenic invader. Cytokine storms have potential to do significant damage to body tissues and organs. If a cytokine storm occurs in the lungs, for example, fluids and immune cells such as macrophages may accumulate and eventually block off the airways, potentially resulting in death. (21)

This fluid overwhelming the lungs is what is happening in some COVID-19 cases and why you are hearing about the increased need for ventilators. If you want to read a pretty harrowing account of this from a medical technician, you can read it here.

While some nutriceuticals will elevate normal immune cellular cytokine levels, vitamins and even herbs are not going to cause a cytokine storm. 

A cytokine storm is a very advanced stage of a disease as the body fights an infection. I prefer that you optimize immune early so that you can nip a virus or other infection in the bud, long before a visit to the hospital.

Getting Back to Prediabetes

“’The healthy folks went through what we saw as a pretty normal immune response,’” said Snyder. “But the insulin-resistant folks — not so much. Their immune systems seemed to be somewhat deficient in launching a proper immune response to infection.

Specifically, he said, levels of immune molecules known as cytokines, which aid in immune cell signaling, seemed to be too low. It may help explain why diabetics tend to get more infections than healthy people, Snyder added.” (22)

We’ve seen diabetes hit harder with acute respiratory disease and mortality rate with COVID-19. If you have sugar cravings, brain fog or some stubborn belly fat, these are clues of insulin-resistance!

If you are prediabetic, you are immuno-compromised as well, if not as severely. You might be prediabetic or insulin resistant even with a healthy diet. We see it all the time.

Our blood sugar panel includes:

  • Fasting glucose
  • HA1c ( a long-term blood sugar marker)


Our thyroid blood test with a thyroid antibody test giving you a complete picture of potential hypothyroidism. If you are wondering if you have weakened immunity due to a thyroid condition, you are not alone!

It took some digging to find answers on this subject. Most of what I found about hypothyroidism is about how the body attacks the thyroid gland in autoimmunity, and less so on how it affects your protection from viruses!

As the thyroid gland plays such a key role in metabolism throughout the body, it makes sense that it supports immune function as well. I was thankful to find this 2019 article out of Argentina by María del Mar Montesinos and Claudia Gabriela Pellizas that explained it really well. (23)

Here are a few highlights from the article linked above:

TH (thyroid hormone) metabolism plays an important role in neutrophil function during infection. 

Although NK (natural killer) cell functionality was impaired in Graves’ patients and restored in the euthyroid state, in vitro treatment with T4 to peripheral blood lymphocytes from these patients did not show any increase in NK cell activity.

Over the past decade, it has become clear that shifts in cellular metabolism are determinants of macrophage function and phenotype. The activities of key enzymes of glycolysis are regulated by THs in these cells, affecting macrophage metabolism and function. Stimulation of the immune system in hyperthyroid rats revealed that monocyte migration and ROS production by macrophages were suppressed. In contrast, hypothyroidism enhanced ROS (Reactive Oxygen Species) release, whereas monocyte migration was not affected.

Kupffer cells are main scavengers constantly clearing gut-derived pathogens from the blood, preventing liver diseases. T3 promoted hyperplasia and hypertrophy of these cells, with a resulting enhancement in the respiratory burst activity.

I also found a 2018 study on T-Cell Function Defect in Hashimoto’s Thyroiditis and a 2016 study on both Grave’s disease and Hashimoto’s that stated, ‘In HT (Hashimoto’s thyroiditis) patients, we found increased proportions of naïve Th17 cells after stimulation with the thyroid self-antigen thyroid peroxidase (TPO) and the Escherichia coli lipopolysaccharide (E. coli LPS).” (24, 25)

Ultimately, you can’t assume you have weakened immunity if you have tested as hypothyroid at some point. But testing now and including a WBC panel and the other markers above could be revealing. If you are constantly fighting a sore throat or colds, that is suggestive that something is off and testing may be timely.


As we all consider the threat of this pandemic, it’s important to consider health as a whole.

Whole body immunity includes:

  • Holistic approaches to support optimal thyroid function
  • Management of blood sugar through diet, lifestyle, and detoxification
  • Healthy digestion, nutrition, and supplementation as needed
  • Stress management, healthy relationships, and good sleep
  • Yearly testing to see what your levels are!




Our Functional Blood Panel  testing service includes:

  • Thyroid panel
  • WBC count and breakdown
  • RBC count and breakdown
  • Blood sugar makers: fasting glucose, HA1c
  • Vitamin D3
  • Private, half-hour review and planning session with Dr. Scott

Add autoimmune thyroid testing for $30

—> Labs are still open, but if you’d prefer to purchase now and wait until the quarantine is over, that is totally fine. We appreciate you supporting our small business in this trying time.

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This article was sourced from