Does Sunlight Help Prevent Respiratory Infections Like COVID-19?

With dozens of do it yourself prevention tips and cures circulating around the Internet, it can get overwhelming to know what works and what doesn’t. One common, but flawed, theory circulating during the height of the Coronavirus outbreak is that of going outside in the sunshine to kill the virus. This advice comes from the fact that sunshine does seem to have various antibacterial properties.

On the face of it, the idea that sunshine would in any way prevent a respiratory infection, might seem silly, but there may be some truth to it. In fact, around the world, in the absence of antibacterial agents, water can be left in sunlight (for hours) with disinfectant results. But how does this apply to our current situation? As it relates to the Coronavirus, not a whole lot, as these properties are limited to waterborne pathogens.

Does Sunshine Have Any Benefits?

However, where sunlight truly does shine – pun intended – is in the form of vitamin D. Most Americans are deficient in this very important vitamin. This is especially true during the winter months when we have less sun exposure. Beyond the proven bone health properties that vitamin D offers, there is ample evidence showing that it can also improve the effectiveness of the immune system. As such, getting a few minutes of sunlight every day can have a beneficial effect. Once again, no study has quantified the benefits of vitamin D as it relates to the Coronavirus specifically, but as long as we moderate our sun exposure, there is no harm in spending some time outside. More intangibly, sunlight can also improve our mood. Not only is it important to get some fresh air, but during times like these, where we are all stressed out due to the quarantines and stay at home orders, we could all use a bit of cheering up.

Anything to Worry About?

On the other hand, there is no evidence that the UVA or UVB rays we get from the sun have a significant effect on the Coronavirus. Further, the amount of UVA or B exposure needed may be so great, that our risk of dangerous skin cancers due to sunburn may be even greater than the risk of contracting the virus itself. We do know that UVC rays are effective against pathogens and are used in many hospitals to clean rooms, floors, etc. but these rays are so intense that severe damage would occur if concentrated on human skin.

It is also important to remember that once we have contracted a virus of any kind, or the Coronavirus specifically, sunlight has little to do with how the virus replicates in our bodies. At this point, we have to rely on our immune system as well as medical interventions that we may need to fight the virus. It is unlikely that spending time in the sun will do much to change that outcome.

How does this relate to bariatric patients?

Most bariatric patients require normal vitamin D levels even more than the typical American. This is because many patients are at a higher risk of osteoporosis – bone density loss – after surgery. Vitamin D allows for the efficient absorption of calcium into the bones, which can remineralize bones. Typically, bariatric patients are very good with their supplementation routine, but during these times it can become more difficult to eat properly and exercise appropriately. Therefore, bariatric patients should pay close attention to their vitamin D intake and while they’re at it get outside and do some exercise to keep on track.

So what is the answer?

If you’re feeling well and you follow local and state laws regarding leaving your house, we recommend that you get some sun, both for its vitamin D synthesizing properties as well as for a change of scenery. Please be mindful of the amount of time that you spend in the sun as excessive sun exposure can also lead to skin cancer. If your doctor has told you that you have a Vitamin D deficiency and you haven’t followed your supplementation regimen, now is as good a time as any to get it started.