Basic overview of the immune system

Our immune system is the collective defense system against disease that classically works to identify foreign microorganisms and protect the body from these invaders. It includes both biological structures and processes.

The immune processes can be broken down to two main types of immunity that work together to keep us healthy: innate immunity and adaptive immunity. The innate immune system is comprised of biological immune responses that were genetically passed down from your parents and present since birth, whereas the adaptive immune system refers to responses that the body has learned and developed from exposure to foreign proteins.

COVID-19 considerations

Coronaviruses are a class of viruses that infect both humans and animals and are often the cause of respiratory infections such as the common cold. The COVID-19 virus is a new type of coronavirus that originated last year and is now responsible for a pandemic.

Currently, the full characterization of this virus is ongoing, but primarily presents with influenza-like symptoms such as:

  • Fever
  • Cough
  • Fatigue
  • Shortness of breath

Build a strong immune system

You can bolster your immune system with evidence-based steps and habits:


Flavonoids (phytochemicals) found in fruits and vegetables have been found in numerous studies to reduce inflammatory markers. We recommend consuming 5–7 servings of vegetables and 2–3 servings of fruit daily.


Dehydration has been found to decrease innate immune functions in the body. For instance, dehydration is linked with a decrease in salivary proteins, like x-amylase or lysozyme, both of which have anti-microbial properties.

To boost your immune system, we recommend limiting your alcohol consumption, as alcohol has long been known to have adverse effects on the immune system and has even been linked with higher susceptibility to acute respiratory stress.

Eat balanced macronutrients

Consume a balanced diet of macronutrients. This includes getting adequate fat, as fat restriction is associated with a decrease in immune function.


A lack of sleep has repeatedly been shown to have a detrimental effect on immunity. Shorter sleep duration and poor sleep continuity has been shown to increase infection risk.


Exercise’s impact on the immune system is complicated and not completely understood. Most experts agree, however, that acute high-stress exercise can be harmful to our immune system as it releases proinflammatory cytokines.


Stress can have a negative impact on our immune system by suppressing our natural immune responses. Practicing mindfulness has been found to be an effective way to decrease both stress and proinflammatory cytokines.


  • Vitamin C — Studies indicate that vitamin C has powerful benefits in decreasing the severity, frequency and duration of the common cold and the incidence of pneumonia. Typical dosing is 500–1000 mg daily, with higher doses during acute infection.
  • Zinc — Zinc is famously known for its immune boosting properties. It is necessary for the thymus-specific hormone Thymulin. Thymulin promotes T cell function such as interleukin-2 production and suppressor functions. Additionally, zinc can help decrease inflammatory cytokines and thus keep inflammation in check during times of illness.
  • Vitamin D — Vitamin D is a hugely beneficial nutrient for our immune systems as it benefits both our innate and adaptive immunity. Classically, vitamin D is known for its effects on calcium and bone health. A vitamin D deficiency is associated with increased autoimmunity.While vitamin D is overall beneficial for the immune system, some studies suggest that taking it for the coronavirus may have adverse effects.
  • Elderberry — Sambucus nigra (elderberry) is an effective immunomodulator for the common cold, influenza, and potentially early stages of corona virus infections.
    Concerns have been raised by research that elderberry is unsafe to use in suspected COVID-19 cases as it can proliferate the immune response and cause progression to respiratory distress syndromes, therefore it is not recommended to use in this scenario.
  • Turmeric — Curcumin is the key ingredient in turmeric, a spice commonly found in most curry powders. Curcumin is known for its anti-inflammatory effects but has also been noted as a potent immunomodulatory agent.

Specific support tips for COVID-19

Psychological stress is an activator of the NLRP3 inflammasome. Based on the understanding virulence and pathogenicity of the SARS corona viruses, this makes the practice of intentional relaxation a critical component to prevention and support of COVID-19 infection.

Do NOT use with COVID-19

Due to the understood mechanism of SARS corona viruses and the risk for respiratory distress syndromes due to excessive activation of the immune system, some agents typically thought to be helpful in illness are recommended to avoid as they stimulate the inflammatory response in a substantial way. These include:

  • Sambucus nigra (Elderberry)
  • Polysaccharide extracts from medicinal mushrooms
  • Echinacea angustifolia and E. purpurea
  • Vitamin D

Likely safe with COVID-19

The agents listed below are other commonly used natural immunostimulatory and antiviral agents which demonstrate an immunomodulatory effect and may restore homeostasis. These specific agents do not appear to increase the inflammatory cytokines involved in the NRLP3 inflammasome and are therefore likely safe for use with COVID-19. Whether these agents mitigate the symptoms or virulence of COVID-19 has yet to be studied and, therefore, the benefit of these agents during COVID-19 infection is unknown.

  • Zinc
  • Garlic
  • Quercitin
  • Astragalus membranaceus
  • Full mycelium mushroom extract
  • Peppermint

To learn more about your immune system and how to improve it for better health and wellness, visit Empowered Health Institute’s website at and download our “Immunity Resource Guide.”

Dr. Jessica Schneider, MD is Board Certified in Internal Medicine.