Avoiding the Sun Can Be as Dangerous as Smoking

Yes you read the title of this blog right. More to follow, but first, given that we are in the last two glorious weeks of summer, the time is now to snatch up any last opportunity to feel those warm summer rays on your skin. There is nothing quite like that feeling. And like most things that feel good, it usually means both that there is something about it that our bodies evolved to deeply need, but also that you have to be very careful and respectful of its dangers at the same time.

I’ve been cultivating some protective color in my skin since spring, so by now I can soak up even more rays without burning. On my days off, I get in a good personal yoga session and a good sweat, in the full sun.

Of course, I am still careful especially when the sun index is high. On your weather App this is very easy to check. A sun index of 3-5 means you are at low risk for skin damage. 6-7 means a moderate risk. 8-10 is high, and above 11 is very high. Damage accumulates based on the index and the amount of time you are exposed. You can get burned in less than 10 minutes when the index is very high. Now that the high days have past, the sun index never gets above 10 (which is still high but not extreme). In the winter, the index only even gets to a 5 at high noon and doesn’t last long. In order to produce your own Vitamin D, it needs to be at least 3.

If you have no color in your skin when you initiate your tanning plan, you will need to start by getting early morning and late afternoon sun when the index is 3 or less. These rays contain a huge amount of infrared rays, which come with their own health miracles (another blog), but are too weak to produce Vitamin D. This infrared rich and soft light does help prepare your skin to begin to produce more melanin though, laying the groundwork for the color you need to handle more time in the sun later.

I emphasize all this because, as I alluded to above, the benefits of sun exposure are not trivial. It goes beyond just Vitamin D, although that is the most obvious and profound biological driver. I am a believer in supplementing with Vitamin D simply given the fact that almost none of us are receiving the amount of sun exposure our bodies evolved to obtain, when we were literally spending our entire lives in the great outdoors. But there is something about sun exposure itself that goes beyond just supplementing with the main molecule it helps your body produce. Like most things in our body, the beautiful complexity cannot be isolated to one variable.

An article from Sweden published in the Journal of Internal Medicine1 accentuates just how important at least some sun exposure can be. Researchers followed close to 30,000 women for 20 years, comparing causes of mortality to differences in sun exposure. One of their conclusions was particularly striking. Nonsmokers with the least amount of sun exposure had a life expectancy that was essentially the same as smokers who got the most amount of sun. In other words, avoiding the sun can be as dangerous as smoking!

They also found that while melanomas did increase with increasing sun exposure, prognosis was actually much worse for melanomas diagnosed in those who had the least amount of exposure to the sun. Although the incidence of melanoma was significantly lower for those who studiously avoid the sun, the risk of dying once you have been diagnosed was eight times greater in this group. And your risk of dying is 4 times greater once you have been diagnosed with nonmelanoma skin cancer if you have been a sun avoider.

In terms of overall cancer, those in the highest sun exposure group did have a relative increase in the percent of death due to cancer. But wait. This increase was found to be due to increased life expectancy! They lived so much longer than those in the lowest sun group, that they had more time to develop cancer, which of course in general is an illness that increases in likelihood with increasing age. In particular, the risk of death from cardiovascular disease and other non-cancer causes was decreased in both the moderate and high sun exposure groups. And given that heart disease is still the number one cause of mortality in both men and women, such a risk reduction is huge.

Another study2 just published two months ago hints that just even simply supplementing with Vitamin D, separate from sun exposure, reduces cardiovascular events. Again, potentially huge considering heart disease is still the biggest threat across the board. But given that it is starting to appear that there is no end to the potential benefits of Vitamin D throughout an incredibly broad spectrum of illness, this is very very significant.

Of course there are many reasons to explain these findings. It could simply be that those who seek out the sun are happier, more active people in general than those who might tend to stay inside or be more sedentary. It may be that being in the sun itself makes you happier, and perhaps it is unrelated to Vitamin D. More likely- it is a “Both, And” on that one. It could be that in Sweden, the risk of severe Vitamin D deficiency is so significant, given the long winters, that making sure you really pay attention to getting sun in the summer is even more important than in other parts of the world.

At the very least, this is yet another cautionary tale that our conventional wisdom about what is good for your health needs to be questioned. We know it can be so frustrating given the wildly contradictory opinions and passions out there on nutrition, supplements, lab values, and yes, sun exposure, to name a few. Once again, here at MD Integrative we take pride in trying to shine a light (no pun intended) on what is real and what is not. And to put all of it in the context of your own personal journey. There is no one size fits all approach when it comes to your health. In the meantime, use caution, but don’t feel guilty when you take a moment to enjoy a little sun on your face.


  1. PG, Epstein E, Nielsen K, LandinOlsson M, Ingvar C, Olsson H (Karolinska University Hospital, Lund University, Lund, Sweden). Avoidance of sun exposure as a risk factor for major causes of death: a competing risk analysis of the Melanoma in Southern Sweden cohort. J Intern Med 2016; 280: 375–387.
  2. Bridie Thompson et al, Vitamin D supplementation and major cardiovascular events: D-Health randomised controlled trial. BMJ 2023; 381:e075230


The information provided through this website and in this blog is informational only, and is not intended to substitute for the advice of your physician or other licensed healthcare professional. As such, you should not use this information to diagnose or treat any health problem or illness without first consulting your provider. In other words- be smart about not going out immediately and taking a 3 hour nap in the mid-day sun right now, especially if you haven’t seen the sun yet this summer! And consult your doctor about the right dose of Vitamin D for you.

Posted by Dr. Rob

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