With a Covid-19 vaccine still far ahead in the future for most of us, our new normal is set to continue for now.
Many are currently taking vitamin supplements to bolster their immune system and help them fight off viruses like the SARS-CoV-2 virus that causes Covid-19.
While some so-called preventive supplements should be avoided altogether (such as the use of bleach, don’t use that!), taking vitamin D and zinc supplements could help to boost your immune system. But does it specifically prevent Covid-19?
At this point, the US National Institutes of Health concludes that there isn’t enough evidence to show that vitamin D and zinc treats or prevents Covid-19. But as scientists have observed some benefits of vitamin D and zinc against coronaviruses, let’s dive further into why these supplements could help fight such an infection.
Low in vitamin D
Earlier studies have shown that vitamin D reduces the risk of respiratory tract infections, apart from Covid-19. Although the benefits varied greatly among these studies, vitamin D supplementation seemed to be more helpful for people who were deficient in it.
Conversely, this would suggest that a deficiency in vitamin D could raise the risk of respiratory tract infection and have an impact on the severity of symptoms.
Recent studies found that Covid-19 deaths tend to be higher in countries farther away from the equator, where many people are prone to vitamin D deficiency because of reduced exposure to sunlight, especially during the winter.
A study published in October (2020) supports the importance of vitamin D for a healthy immune system. In this study, patients with lower vitamin D levels were more likely to test positive for Covid-19.
This held true even when other factors that could worsen Covid-19, such as age, obesity and other medical conditions, were taken into account. Still, these studies are observational, meaning that the researchers collect data on the participants over time, rather than assigning them specific treatments.
This means that it is almost impossible to show a direct cause-and-effect relationship between vitamin D and Covid-19. To really prove a link, more randomised controlled trials are needed.
In one such study, doctors in Spain gave 76 Covid-19 patients a treatment of hydroxychloroquine (a previously promising treatment for Covid-19) and azithromycin (an antibiotic). Doctors further prescribed calcifediol, an active form of vitamin D, to 50 random patients.
The other 26 patients did not receive vitamin D. Just one of the patients who received vitamin D as part of their treatment ended up in the intensive care unit (ICU). But half the group that didn’t receive vitamin D ended up in the ICU.
The results of this study suggest that vitamin D could be helping to manage the symptoms of those with Covid-19 such that they do not require ntensive care. However, more research is needed to know if this is true.
What about zinc?
Zinc is a micronutrient that impacts all organs and cells, and is the second most-common trace mineral found in the human body. It plays a critical role in regulating our metabolism and the immune system.
Many studies over time have shown that people with low levels of zinc are more likely to develop infections and certain health conditions. A deficiency in zinc suppresses immune function.
Even a mild or moderate level of zinc deficiency can impair the functions of white blood cells like macrophages and neutrophils, as well as natural killer cell and complement activity.
This is as zinc is responsible for developing and activating T-lymphocytes, which interact with their fellow specialised white blood cells to fight off the harmful microorganisms like viruses and bacteria that invade our body.
So it’s pretty clear that our immune system would be impaired without adequate zinc levels. Some research has indicated that zinc may help fortify the immune system against Covid-19 as well.
Spanish researchers reported finding a link between low zinc levels in the blood and poor health outcomes among patients with Covid-19 in October (2020). They examined the data on 611 patients who had shown symptoms of Covid-19. Among the 249 patients who died, it was observed that their average blood zinc level was 43 microgram per decilitre.
The researchers concluded that lower zinc levels in patients at admission correlates with higher inflammation during the course of infection and a poorer outcome. However, they added that further studies are required to assess the therapeutic impact of this association.
A separate article that was recently published in the Journal of Medical Virology theorised that zinc may inhibit RNA (ribonucleic acid) viruses, including coronaviruses, and that this could be the antiviral effect we need against the SARS-CoV-2 virus.
This hypothesis is partially based on a 2010 study, which found that zinc, when combined with an ionophore (a chemical that transports an ion across a cell membrane), inhibited the replication of the coronavirus that causes SARS (severe acute respiratory syndrome).
So, should you take zinc and vitamin D supplements?
Improving immunity
Zinc can be helpful in preventing the symptoms of a cold from becoming worse. Most people get enough zinc from their food, e.g. oysters, fortified cereals, beans and dairy products.
However, some groups like vegetarians, people with gastrointestinal diseases and those who drink alcohol excessively are at higher risk of zinc deficiency and should supplement their diet.
When you have a cold, you can take a zinc supplement ranging between 13.3 milligrams to 23 milligrams every two hours for not longer than one week.
Just like zinc, we don’t yet know if vitamin D will reduce symptoms of Covid-19; but considering its benefits to the immune system, it is a good enough reason to consider taking a vitamin D supplement.
A supplement of 10 micrograms a day is sufficient for most people. Do not take more than 100 micrograms without supervision. Vitamin D can also be found in fatty fish, egg yolks, red meats and fortified cereals.
Remember, although zinc and vitamin D supplements are beneficial and recommended, they are still not replacements for washing your hands, wearing a face mask and practising physical distancing.
By Datuk Dr. Nor Ashikin Mokhtar
Published in Star Newspaper, December 14. 2020
