Researchers are working hard to find good treatments for COVID-19 and strategies to prevent it from being as severe. A new study suggests one possibility might already be in many medicine cabinets… Vitamin D3.
Vitamin D is known to play a role in our immune response and to reduce potentially harmful inflammatory responses in the body. We make large amounts of this vitamin when the sun shines on our skin and we can also get it from our food or by taking a supplement. In northern countries, like Canada, a vitamin D supplement is recommended from October until April, when the sun’s rays are not strong enough (and we’re too bundled up due to cold temperatures!) to produce adequate amounts for ideal health. But sunshine is good for us in more than one way.
Benefits of sunshine
We’ve all noticed that viral infections, like colds and the flu, tend to be less common in the summer when the sun’s rays are stronger. There are several mechanisms that have been proposed that could explain this:
Vitamin D helps the body to produce more macrophages, immune system cells that destroy invading germs by essentially “eating” them.
Ultraviolet rays destroy microbes in the air, so more sunshine means viruses will not live as long outside the body in the air or on surfaces outdoors.
Vitamin D helps prevent inflammation from getting out of control, as is noted in severe cases of COVID-19.
Skin that is exposed to the sun also releases large amounts of nitric oxide into the bloodstream. Nitric oxide relaxes blood vessels, reduces clotting (a problem associated with COVID-19) and, at least in lab cultures, prevents SARSCoV2 and other similar viruses from reproducing. Interesting side note: drugs like Viagra, used to improve men’s sexual function, work by blocking the breakdown of nitric oxide resulting in increased blood levels and dilation of blood vessels.
Vitamin D increases the action of an enzyme called angiotensin-converting enzyme-2, or ACE2, that is associated with improved COVID-19 outcomes.
Pigment in the skin filters the sun, providing protection from harmful rays, but it also reduces the amount of vitamin D formed in the skin. This has been suggested as one possible factor contributing to higher rates of vitamin D deficiency as well as increased rates of severe cases of COVID-19 among people of colour. Social and economic issues are also believed to be contributing to these excess cases.
Our general health affects how much active vitamin D we have in our bodies. The healthier you are, the more your vitamin D levels will rise naturally. Eating right, exercising, not smoking, spending time outside in the sun and keeping a healthy weight all help.
Of course, a vitamin D supplement won’t raise nitric oxide levels as sunshine does, but researchers are testing medications that can raise nitric oxide blood levels as well as whether inhaling nitric oxide gas can raise blood levels in a similar fashion. A preliminary study, done on cells from monkeys, showed that nitric oxide has antiviral action against SARSCoV2 and reduced blood clotting as well as dilating blood vessels.
There are those who point out that we don’t yet have concrete evidence that higher levels of vitamin D will protect us from severe forms of COVID. Like so much else with this new coronavirus, we will need to wait for the results of studies to know for sure whether this approach will save lives.
But this makes me think of the discussion about masks, where we were discouraged from wearing them at first because they weren’t “proven” to help (I think they actually said “there was no evidence they helped”…). Vitamin D supplements are considered safe in doses up to a maximum of 4000 units daily in adults and taking a supplement in the winter, when the sun’s rays are too weak to form vitamin D in our skin, has been encouraged for health reasons for as long as I can remember. A common dose is 1000 units daily and it’s readily available and inexpensive in pharmacies and many grocery stores.
Coronavirus spikes may be a pain reliever…
The other interesting COVID-related news I read this week, was that the coronavirus appears to have a pain-numbing effect. The Centers for Disease Control and Prevention (CDC) in the US estimate that about 40% of people with the virus do not have any symptoms. Scientists suggest that this could be because the coronavirus can block a pain signalling pathway, resulting in some of those infected being unable to feel the discomfort the virus infection. This would explain the asymptomatic cases and lack of symptoms early in the course of the infection, allowing increased spread of the virus as people don’t realize they are sick.
The spikes on the coronavirus attach to the ACE2 receptor on the surface of our body’s cells, like a key fitting into a lock. This is how they get into cells to infect them. But the spike proteins can also attach to another receptor on the cell surface called neuropilin and block it. Since this receptor is part of a pain pathway, the virus (or just its spikes, as was used in an experiment done on rats) blocks the pain signals that would otherwise be sent to the brain through this pain system.
So, besides providing a possible explanation for why people with milder forms or in the early stages of the infection don’t feel sick, these scientists may have found a new way to relieve pain in the future. If they could create a drug that mimics this action of these spike proteins, without the rest of the virus, we might have a new class of pain medications. Of course, this would be far off some time in the future, but it’s interesting to see how science works – often by observing an action in nature, analyzing how it occurs, then using this information for our benefit.
Can you catch the virus through your eyes?
Another article I read this week was about the potential to catch COVID through the eyes. It is thought that very few cases of the disease are caused by virus entering the body through the eyes, although they do tell us it’s a possibility. However, someone thought to assess what percentage of a group of hospitalized patients in China wore glasses daily, as compared to the local population. They noted that, although 31.5% of the population wore glasses at least 8 hours a day, only 5.8% of those in hospital at that time for severe COVID did so.
Of course, this is just an “observational” study that doesn’t prove anything, but it does suggest that the eyes could be a more important route of entry for viruses than we currently believe. It suggests that we should take another look at this issue. Meanwhile, I think I might wear my glasses instead of my contacts when I go out… just in case it does make a difference, Besides, I really like my new glasses!
And I always take a vitamin D 1000iu supplement in the winter unless I go somewhere warm and sunny. I guess I’ll be taking one all winter this year while I look at photos of Florida and Spain to lift my spirits when it’s too stormy to go outside…
References:
Vitamin D for Covind-19: New Research Shows Promise – Medium elemental
How Sunlight, the Immune System, and Covid-19 Interact – Medium elemental
COVID-19: Nitric oxide shows promise as antiviral treatment – Medical News Today
Association of Daily Wear of Eyeglasses With Susceptibility to Coronavirus Disease 2019 Infection – JAMA Network
COVID-19: What role does vitamin D play? – Medical News Today
