Quercetin, Zinc, Vitamin C and Vitamin D3: Can They help Against Coronavirus? (2022)
The claim: Vitamin D, Vitamin C, Zinc and Quercetin can prevent or treat COVID-19?Since the early stages of the pandemic, people have claimed supplements like quercetin, zinc, vitamin D and vitamin C can help treat and prevent COVID-19. But public health organizations and experts say there is little evidence these products are effective at treating or preventing COVID-19?
|McCullough et al. Reviews in Cardiovascular Medicine, 2020|
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 analyzed in a comprehensive, updated and non-biased manner in order to come up with the best 'evidence-based' decision.
|Nutraceutical Therapy by Mode of Action|
1. Vitamin D3 - Anti-inflammatory and Anti-coagulantVitamin D, as an immuno-modulator, is a perfect candidate for countering the immune dysregulation common with OVID-19.
2. Quercetin - Anti-inflammatory, anti-coagulant, zinc ionophore and anti-viral
3. Zinc - Anti-viral
Improving zinc intake/zinc status improves/modulates/enhances immune function. The flip side is, while some aspects of immunity slow, others increase. Uncontrolled immune responses drive excess inflammation. Zinc helps to balance all of this.
“Zinc is involved in numerous aspects of cellular metabolism. It is required for the catalytic activity of approximately 100 enzymes and it plays a role in immune function, protein synthesis, wound healing, DNA synthesis, and cell division. Zinc also supports normal growth and development during pregnancy, childhood, and adolescence and is required for proper sense of taste and smell.”
Excessive doses may interfere with copper absorption, which could negatively affect your immune system as it can cause copper deficiencies, blood disorders and potentially permanent nerve damage. Zinc can also impair the absorption of antibiotics, and use of zinc nasal gels or swabs has been linked to temporary or permanent loss of smell.
4. Curcumin and Turmeric - Anti-inflammatory and anti-viralCurcumin, a yellow carotenoid from turmeric, is well known for its anti-inflammatory and free radical-scavenging effects.
5. Nigella Sativa (Black Seed Oil) and Cytokine Storm - Anti-inflammatory
Black seed oil is extracted from N. sativa seeds and has been used in traditional medicine for over 2,000 years due to its many therapeutic benefits.
6. Vitamin C - Anti-inflammatory
Vitamin C, which most of us reach for with any cold or
flu, was used in high doses to great effect by COVID-19
early treatment doctors.
Vitamin C may be one of the most well-known
immune nutrients that protect against immune
deficiencies and which supports the prevention and
recovery from the common cold and upper-respiratory
issues, and also protects your cardiovascular system,
eyes, skin, and other parts of your body. Research has
found that vitamin C may help to optimize the immune
Do take note that the vitamin C dosages given in the
hospitals intravenously are different from those over
the counter vitamin C supplements. Therefore, when you
come across studies on vitamin C, you need to
differentiate those that are given intravenously vs
oral vitamin C.
Vitamin C and COVID-19
Check out the evidence tracker on vitamin C and
COVID-19 from c19vitaminc.com (constantly updated).
Safety: 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.
While generally considered safe even in high doses,
way too much vitamin C — anything above 2,000
milligrams daily—can cause headaches, insomnia,
diarrhea, heartburn, and other issues.
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. To be on the safe
side, you may also request for your kidney functions
to be monitored.
For long-term, daily use, your best bet is to eat a
diet that is full of high quality organic vegetables
and fruits that are minimally processed. Not only will
you get vitamin C, but you will get all the other
accessory nutrients and micronutrients that are needed
to optimize it.
Vitamin C, Omicron and Deltacron
Will Vitamin C Work Against Omicron or Deltracron?
Vitamin C is not variant specific because it's
primary mode of action is to support the body’s
immune system which reacts in a variety of ways
against viral attack, not just in a specific
antibody reaction to a specific spike protein.
Related: Best Vitamin C Supplement
Safety: 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.
7. 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."
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.