Quercetin, Zinc, Vitamin C and Vitamin D: Can They help Against Coronavirus? Updated June 2021
COVID-19 kills some people and spares others. How do you ensure that you are on the right side of the statistics? There are just too many self-proclaimed medical experts recommending all kinds of supplements for COVID-19 out there. On one side are experts telling you that supplements don't work and you should avoid them and just rely on wholesome foods. On the other, are experts telling you to take all kinds of supplements that will help protect you against COVID-19. Do they actually work? Some supplements do have evidence and some don't.
This guide is based on various references to scientific literature and hopefully, can help you make sense of the options and to separate the facts from fiction.
|Image credit: ClevelandClinic|
How do you deal with different expert groups dishing out conflicting guides? A common issue is that certain groups have pre-defined narrative that they would like to support. Therefore, only studies that support that pre-defined narrative are picked and cited as references. This is what we call as 'cherry-picking'. Cherry picking will naturally lead to a 'biased' decision. In order to avoid that, scientific information needs to be analysed in a comprehensive, updated and non-biased manner in order to come up with the best 'evidence-based' decision.
Quercetin and COVID-19
There is evidence that vitamin C and quercetin co-administration exerts a synergistic antiviral action due to overlapping antiviral and immunomodulatory properties and the capacity of ascorbate to recycle quercetin, increasing its efficacy.
- Vitamin D3: 1000–3000 IU/day. Note RDA (Recommended Daily Allowance) is 800–1000 IU/day. The safe upper-dose daily limit is likely < 4000 IU/day. Vitamin D deficiency has been associated with an increased risk of acquiring COVID-19 and from dying from the disease. Vitamin D supplementation may therefore prove to be an effective and cheap intervention to lessen the impact of this disease, particularly in vulnerable populations, i.e. the elderly and obese. (Amazon)
- Vitamin C: 500 - 1,000 mg BID (twice daily). (Amazon)
- Quercetin: 250 mg daily. It is likely that vitamin C and quercetin have synergistic prophylactic benefit. Quercetin should be used with caution in patients with hypothyroidism and TSH levels should be monitored. (Amazon)
- Melatonin: 6 mg before bedtime (causes drowsiness). (Amazon)
- Zinc: 30 - 40 mg/day (elemental zinc). Zinc lozenges are preferred. (Amazon)
- Ivermectin for
- prevention in high-risk individuals (> 60 years with co-morbidities, morbid obesity, long term care facilities, etc): 0.2 mg/kg per dose (take with or after meals) — one dose today, repeat after 48 hours, then one dose weekly. (also see ClinTrials.gov NCT04425850).
- Post COVID-19 exposure prevention: 0.2 mg/kg per dose (take with or after meals) — one dose today, repeat after 48 hours.
- Ivermectin has a number of potentially serious drug-drug interactions. Please check for potential drug interaction at Ivermectin Drug Interactions - Drugs.com. The most important drug interactions occur with cyclosporin, tacrolimus, anti-retroviral drugs, and certain anti-fungal drugs.
- Quercetin has one moderate drug interaction with warfarin. Do not take quercetin without medical advice if you are using warfarin.
- Vitamin D3 — 4000 IU/day. (Amazon)
- Vitamin C: 500 - 1,000 mg BID (twice daily) (Amazon)
- Quercetin: 250 mg twice a day. (Amazon)
- Melatonin: 10 mg before bedtime (causes drowsiness). (Amazon)
- Zinc: 100 mg/day. Zinc lozenges are preferred. (Amazon)
- Ivermectin: 0.2–0.4 mg/kg per dose (take with or after meals) — one dose daily, take for 5 days or until recovered.
- Fluvoxamine: 50 mg twice daily for 10–14 days. Add to ivermectin if: 1) minimal response after 2 days of ivermectin; 2) in regions with more aggressive variants; 3) treatment started on or after day 5 of symptoms or in pulmonary phase; or 4) numerous co-morbidities/risk factors. Avoid if patient is already on an SSRI (selective serotonin reuptake inhibitor).
- Nasopharyngeal Sanitation: Steamed essential oil inhalation 3 times a day (i.e. vapo-rub) and/or chlorhexidine/benzydamine mouthwash gargles and Betadine nasal spray 2–3 times a day.
- Aspirin: 325 m/day unless contraindicated.
- Pulse Oximeter: FLCCC also recommend monitoring your oxygen saturation with a pulse oximeter and to go to the hospital if you get below 94%.
- Quercetin oral 500 mg twice a day.
- Vitamin C 3000 mg
- Vitamin D3 5000 IU
- Zinc sulphate 220 mg
Vitamin D and COVID-19Based on several publications and studies, vitamin D seems to be the “most promising” supplement for COVID-19 protection. Many studies have showed the link between vitamin D deficiency and COVID-19.
Of those with a vitamin D level below 20 ng/ml (deficiency), 12.5% tested positive for SARS-CoV-2, compared to 8.1% of those who had a vitamin D level between 30 and 34 ng/ml (adequacy) and 5.9% of those who had an optimal vitamin D level of 55 ng/ml or higher.
Another study, published in JAMA (JAMA Netw Open - Sep 2020) found that persons who are likely to have deficient vitamin D levels at the time of COVID-19 testing were at substantially higher risk of testing positive for COVID-19 than were persons who were likely to have sufficient levels.
The same team above, has also published a preprint article: A study at the University of Chicago of over 4,000 patients that found that untreated vitamin D deficiency was associated with an increased risk for COVID-19 infection.
According to the Association of American Physicians and Surgeons’ home-based guide to treating COVID-19, vitamin D, C and zinc are necessary.
Some doctors also recommend adding a B complex vitamin. Zinc is critical. It helps block the virus from multiplying. Hydroxychloroquine is the carrier taking zinc INTO the cells to do its job.
To maintain healthy levels, only 400 to 800 IU (15 to 20 mcg) of vitamin D is required daily, but, to boost low levels, higher doses, such as 2,000 IU daily, are used and are generally safe.
In December 16, 2020, Rob Verkerk, Ph.D., founder and scientific director of the Alliance for Natural Health, announced the launch of an international vitamin C campaign in response to the Nutrients review, which "puts all the arguments and science in one, neat place."
Word of Caution - The U.S. Recommended Dietary Allowance (RDA) for vitamin C is 75 to 120 milligrams per day. Taking large doses of vitamin C (ascorbic acid) on a regular basis lowers your level of copper, so if you are already deficient in copper and take high doses of vitamin C, you can compromise your immune system.
Temporarily taking megadoses of vitamin C supplements to combat a case of the cold or flu is likely not going to cause a problem.
Many vitamin C supplements that are above the US RDA are sold in the market. It’s important to seek a physician’s advice if you intend to take high dose vitamin C on a long term basis. High doses of vitamin C (over 500 mg per day) over the long-term may increase the risk of cataracts. High-dose vitamin C can also reduce the effectiveness of certain medications and interfere with certain blood tests.
Related: Best Vitamin C Supplements
Zinc and COVID-19Foods that are high in zinc include oysters, crab, lobster, mussels, red meat, and poultry. Cereals are often fortified with zinc. Most multivitamin and nutritional supplements contain zinc.
As of December 2020, there are 40 studies that have been launched to investigate the benefits of Zinc against COVID-19. You can review the status of these trials on clinicaltrials.gov.
Taking zinc long term is typically safe for healthy adults, as long as the daily dose is under the set upper limit of 40 mg of elemental zinc (PubMed).
Excessive doses may interfere with copper absorption, which could negatively affect your immune system as it can cause copper deficiencies, blood disorders, impair the absorption of antibiotics and potentially permanent nerve damage or loss of smell.
Zinc Sulphate is also part of Dr. Vladimir Zelenko anti-coronavirus experimental protocol. Please take note that the protocol is experimental and has not been 100% proven. Do discuss with your doctor before taking the medication as per the protocol. You can check out his publication in the International Journal of Antimicrobial Agents.
Based on the statement released on 2 October by the U.S. president’s physician, zinc is also part of the treatment given to the US President. According to the president's physician, "Trump has been taking zinc, vitamin D, famotidine, melatonin and a daily aspirin.”
Melatonin and COVID-19
"Patients who used melatonin as a supplement had, on average, a 28% lower risk of testing positive for SARS-CoV-2. Blacks who used melatonin were 52% less likely to test positive for the virus."
- Melatonin: 6 mg before bedtime (causes drowsiness).
Molecular Hydrogen and COVID-19Molecular hydrogen has been shown to have anti-oxidant and anti-inflammatory properties. It is 'the one and only' antioxidant that can both penetrate the mitochondria and neutralize the reactive oxygen species (ROS) (Med Gas Res. 2020).
Application of H2, may provide an effective adjunctive medicament to O2 inhalation in the treatment of COVID-19 for the critically ill. Although this method is recommended and practiced in the People’s Republic of China with oxygen/hydrogen mixed gas noted to significantly reduce dyspnea, it is not widely used elsewhere. To date, only one clinical trial using oxyhydrogen for the treatment of COVID-19 infection has been registered with the US National Library of Medicine, with a further four clinical trials registered with The Centre for Evidence-Based Medicine (CEBM).
It is the authors’ opinion that inhalation of H2 would be a more effective delivery mechanism for patients with moderate/severe symptoms of COVID19. Also worthy of notation is that currently, most, but not all clinical trials have been based on inhalation of H2, with this also being the preferred delivery method as recommended by The National Health Commission of the People's Republic of China.
Published in June 2020 (Journal of Thoracic Disease. 2020), this China study is the first multicenter randomized clinical trial that verifies the efficacy and safety of H2-O2 (mixed hydrogen gas and oxygen gas) inhalation in patients (n=90) with COVID-19.
Patients with COVID-19 frequently presented with dyspnea, coughing, chest pain and distress, and oxygen desaturation which cannot be rapidly relieved with other existing therapies (including oxygen therapy). The therapeutic effects of H2-O2 became significant as early as days 2 and 3 and the reduction of most respiratory symptoms persisted till the end-of-treatment.
The authors also concluded that the safety profiles of H2-O2 have rendered H2-O2 inhalation particularly suitable for relieving difficulty in breathing and other breathing symptoms in patients with COVID-19, regardless of the disease severity.
It was discovered and reported in Nature in 2007 by a team in Japan, that inhaled hydrogen gas could act as an antioxidant and protect the brain from free radicals. This sparked the interest in its potential health benefits worldwide and led to many published and on-going clinical research.
B VitaminsB vitamins may constitute a long list, but each one is important for different reasons. B vitamins are especially effective in boosting your immunity when you combine the foods containing them so they can all work together for maximum effect. These include vitamin B1 (thiamin), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid) and B7 (biotin).
B12, also known as cobalamin, is a powerful cold- and flu-fighting nutrient in your system, as is vitamin B6, another important, germ-combating vitamin that naturally benefits and strengthens your immune system and even protects against the damaging effects of air pollution.
Vitamin B9 and folic acid help repair tissues and aid in cell metabolism and immune support. They’re found in dark leafy greens, wild-caught, cold water fish like herring, mackerel, sardines, anchovies and wild-caught Alaskan salmon, and pastured, organic chicken.
N-acetyl cysteine (NAC), meanwhile, is a precursor of glutathione, and may protect against coagulation problems associated with COVID-19, as it counteracts hypercoagulation and breaks down blood clots.
Selenium is also important, as some of the enzymes involved in glutathione production are selenium-dependent.
ConclusionDo take note that the dosages for micronutrients or vitamins are higher for treatment as opposed to maintenance or preventive. This is probably due to higher demand of the body or the deficiency of the micronutrients are worse during a complicated viral infection. However, for prevention or maintenance, the dosages for most of the micronutrients are much lower.
- Wear protective face mask. This is to protect not only yourself but others.
- Abundant evidence suggests that eating whole in fruits, vegetables and whole grains—all rich in networks of naturally occurring antioxidants and their helper molecules—provides protection against free radicals.
- Getting Enough Sleep
- Avoid sugar, red meat and processed foods.
- Don't smoke.
- Take steps to avoid infection, such as washing your hands frequently, using hand sanitizer and cooking meats thoroughly.
- Try to minimize stress.
- Drink enough water to keep your body hydrated.
- Avoid excess alcohol.
- Avoid crowded areas.
- Regular physical activity (outdoor activities may not be allowed in countries with 'lock-down'). Those with active lifestyle has lower risk if hospitalised as compared to those with sedentary lifestyle (Infectious Diseases and Therapy, 2021)
- Consult your nearest local healthcare provider if you have any doubt.