The following info is mostly taken from the Healthline.com site, where you will find all the links to the various subjects listed below.
Vitamin D – Has been highly researched in connection with COVID-19 and has shown that it can expedite healing and stall inflammation in the respiratory system. Many professionals admit that Vit. D could possibly help protect individuals from the virus.
• Fat-soluble nutrient essential to the health and immune system.
• Decreases inflammation.
• Many people are deficient, which increases risk of upper respiratory tract infections.
• Can strengthen immune system; respiratory function; reduce infections; aid anti-viral response.
• 1,000 to 4,000 IU of Vit D per day is sufficient for most people; much higher doses can be taken.
Zinc –
• A mineral essential for immune system function – anti-viral and anti-inflammatory.
• Needed for immune cell development and communication.
• Protects tissue barriers in the body and help prevent foreign pathogens.
• Deficiency very common in older adults.
• Can be taken long-term; no more than 40 mg per day.
• Shown to help with respiratory infections and reduce length of illness.
Vitamin C -
• Plays vital role in protection against infection and supporting immune health.
• Helps in clearing out dead cells and replacing them with new ones.
• A powerful antioxidant, protecting against damage from oxidative stress, due to free radicals.
• Reduces the duration and severity of upper respiratory tract infections, including the common cold.
• Recommended daily doses - 250 and 1,000 mg or to bowel tolerance; upper limit 2,000 mg
Elderberry - Black elderberry(Sambucus nigra) – Benefits and Dangers – be sure to read; there are MANY benefits.
• One of the most commonly used medicinal plants in the world.
• Has long been used to treat infections.
• Indigenous people used to treat fever and rheumatism; ancient Egyptians used to improve their complexions and heal burns.
• Can reduce upper respiratory symptoms caused by viral infections.
• An Ionophore for Zinc – Enhances its effectiveness.
Echinacea is a genus of plants in the daisy family. Certain species have been shown to improve immune health and may have antiviral effects against several respiratory viruses, including respiratory syncytial virus and rhinoviruses.
B Complex Vitamins - B vitamins, including B12 and B6, are important for healthy immune response. Yet, many adults are deficient in them, which may negatively affect immune health.
Garlic has powerful anti-inflammatory and antiviral properties. It has been shown to enhance immune health by stimulating protective white blood cells like NK cells and macrophages. However, human research is limited.
Astragalus is an herb commonly used in traditional Chinese medicine (TCM). Animal research suggests that its extract may significantly improve immune-related responses.
Medicinal Mushrooms have been used since ancient times to prevent and treat infection and disease. Over 270 recognized species of medicinal mushrooms are known to have immune-enhancing properties. Cordyceps, Lion’s Mane, Maitake, Shitake, and Reishi, are all types that have been shown to benefit immune health. Turkey Tail is another medicinal mushroom that has powerful effects on immune health. Research in humans indicates that Turkey Tail may enhance immune response, especially in people with certain types of cancer. Products can be found in the form of tinctures, teas, and supplements.
Quercetin belongs to a group of plant pigments called flavonoids, which are antioxidants that give many fruits, flowers, and vegetables their colors. Antioxidants have been shown to neutralize free radicals. It has been used to help with allergies, asthma, heart attacks, hypertension, arthritis, bladder infections, diabetes, and even cancer, along with a plethora of other illnesses that plagues mankind. Even though knowledge of quercetin has been around since at least 1857, has thousands upon thousands of studies and countless positive results, mainstream medicine still can’t confirm that it is actually beneficial, nor can they seem to decide if people should be using it.
Naturopathic practitioners of every description have seen the positive results in their patients and seem to have no qualms about recommending quercetin, especially if it is combined with Bromelain. It has most often been used by adults in doses of 250-1000 mg, by mouth daily for up to 12 weeks.
WebMD lists several drugs that could be incompatible with quercetin, including possible side-effects, cell pump inhibition, loss of the drug’s effectiveness, etc.; siting mostly that it “could change the effects and side effects of these medications.” They are very fond of saying things like “more study is needed”; “there is no clear evidence”; “it has not been proven”.
Nature gave certain foods to us to keep our bodies Healthy. It is stated in the Bible and has proven true for centuries, so it makes one wonder why our scientists cannot do some simple chemistry to show how and why. It would be very helpful if they could spend some of their lab time helping to set standards for how much should be taken by whom, based on their condition, age, and body weight to eliminate all the doubt about whether Nature's gifts are actual helpful.
Quercetin is a classic example of how natural medicine can give the body the tools it needs to heal itself. All of the natural medicines we have listed here are just that – tools that the body uses to heal itself. The body is the healer. It alone has the intelligence to repair the damage and sustain its Health, if only we will stop poisoning it.
Here's a list of recent studies of the biological and pharmacological activities of quercetin on the NIH website -
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6141818/figure/T1/
Some great info on quercetin from the Dr. Axe site -
https://draxe.com/nutrition/quercetin/
Here is a good article on Immune Boosting from Allina Health -
https://www.allinahealth.org/healthysetgo/prevent/six-ways-to-boost-your-immunity-before-you-get-sick