Natural Ways to Boost Immune Function

By: Arturo Portales, DO


During this current outbreak of Covid-19, I am asked on a daily basis what we can do to prevent becoming infected. Social distancing is the obvious answer, but I believe there is a lot more we can and should do. We will not be socially distancing ourselves forever (thankfully) so how do we keep from getting infected?

The CDC has outlined several strategies, which I will re-post here and the IFM medical education team has presented several strategies in the following: 

Prevention Strategies in Alignment with the Centers for Disease Control and Prevention


  • Wash your hands. Soap actually destroys the virus so washing for 20 seconds is effective.
  • Hand sanitizer: it should be at least 60% alcohol. Avoid hand sanitizers containing triclosan as this is a known hormone disrupter. 
  • Cover your mouth and nose when coughing or sneezing with a tissue. If tissue is not available, then cough or sneeze into your arm. 
  • Avoid touching your face
  • Keep surfaces clean such as door knobs, computer keyboards, phones, remotes, and steering wheels.


  • Stress Reduction: chronic stress can suppress the immune system. Practice stress reduction strategies regularly.
  • Sleep: Get plenty of sleep as this improves immune function.
  • Exercise: moderate, regular exercise improves the immune system by reducing stress hormones, improving circulation, and increasing white blood cells and antibodies. Exercise also improves lung capacity and cognitive function. 
  • Proper diet/nutrition: Eat plenty of bright-colored fruit and vegetables to boost immunity. Eat 10 servings of fruit and vegetables per day and the majority should be vegetables. 

Natural Means of Boosting Immunity

  • Self-care: When battling upper respiratory infections, stay hydrated and get plenty of rest. Drink plenty of fluids including homemade vegetable or bone broths. Herbal teas and hot drinks can also help keep you hydrated and reduce symptoms. Good choices are peppermint, eucalyptus, chamomile, hot water, lemon, honey, and cinnamon. 
  • Sore Throats: salt water gargles are excellent for loosening mucous, and help fend off bacterial infections as well as soothe the pain. Two tablespoons of honey in hot water can also help to soothe and decrease throat inflammation and pain. Chamomile and peppermint teas are also helpful for soothing irritated sore throats, as are teas or infusions made from marshmallow root and licorice root, both of which can act as soothing demulcents.
  • Respiratory congestion & sinuses: For respiratory congestion, use a humidifier, vaporizers, or steam inhalers, or spend time in steamy baths or showers. Vaporizers and inhalers can also be used with decongestants or essential oils such as eucalyptus, menthol, peppermint, or frankincense. Nasal xylitol sprays are very beneficial, as is nasal irrigation using a neti pot or nasal irrigation bottle. Buffered saline is easy to make or can be purchased in packets and eliminates any irritation to delicate, irritated mucous membranes.

Supplements, nutrients, and foods to support immune function

There are several nutrients, plant-based botanicals, and supplements that can boost immune function and provide symptom relief during illness, and may help to shorten the duration of illness. For preventing and treating viral upper respiratory infections, consider some of the following:

  • Vitamin C: Vitamin C may help to prevent infections, including those caused by bacteria and viruses. Regularly administered vitamin C has been shown to shorten the duration of colds, and higher doses of vitamin C during an illness can also act as a natural antihistamine and anti-inflammatory.
  • Vitamin D: Vitamin D, known as the “sunshine vitamin,” is one of the most important and powerful nutrients for supporting the immune system. Numerous studies have shown that it helps reduce the risk of colds and flu. Unfortunately, a high percentage of the population is deficient, so daily supplementation (ideally in the form of vitamin D3) offers the best protection.
  • Vitamin A: For short-term use and particularly for those with moderate vitamin A deficiency, supplementation can be extremely helpful in supporting the body’s ability to fight infections, particularly with regard to respiratory infections.
  • Zinc: Zinc plays a significant role in boosting immunity. Often available as lozenges, zinc can help to reduce the frequency of infections as well as the duration and severity of the common cold when taken within 24 hours of onset.
  • Selenium: Selenium, a key nutrient for immune function, is also an antioxidant that helps boosts the body’s defenses against bacteria, viruses, and cancer cells. It may particularly help to protect against certain strains of the flu virus. Selenium is easily obtained from foods, with the richest source being Brazil nuts.
  • Honey: Honey, preferably raw, is a good demulcent (it relieves minor pain and inflammation of mucous membranes), has antioxidant properties, and has some antimicrobial effects. It is helpful for coughs and sore throats and can be added to hot tea.
  • Garlic: Garlic contains a variety of compounds that can influence immunity. Some studies have shown that both fresh garlic, as well as aged garlic extract, and some other garlic supplements, may reduce viral upper respiratory infection severity as well as function in the prevention of infection with viruses that can cause colds.
  • Probiotics: Probiotics contain “good bacteria” that not only support the health of the gut but also influence immune system functioning and regulation. Studies have shown that probiotic use can decrease the number of respiratory infections, particularly in children.
  • CBD: full spectrum CBD will also boost the immune system. There are CB2 receptors on cells of the immune system. CBD has been shown to downregulate cytokine and chemokine production and upregulate T regulator cells which results in the suppression of inflammatory responses. Cytokines are signaling proteins that are secreted by the immune cells when stimulated. Suppression of cytokines by CBD helps to lower the inflammatory immune response. 

*All information subject to change. Images may contain models. Individual results are not guaranteed and may vary.