Vitamin D & Health: Sun or Supplements?

Updated: Dec 14, 2020

Is your ability to produce vitamin D from sunlight the only good reason to get out in the sun? If you can simply supplement vitamin D, do you even need to get sun exposure? Does sun exposure provide health benefits beyond those of vitamin D production? Could you be hindering your health by supplementing vitamin D rather than proactively getting out in the sun to produce it yourself? Lets explore!

First, a few reasons vitamin D is extremely important (among many others):

  • Vitamin D affects your brain, heart, and your immune system. Virtually all your body’s cells have receptors for vitamin D, and it influences gene expression positively. (1,2)

  • Vitamin D is important for bone health. (1,2,3)

  • Vitamin D is important for immune system function.

  • Vitamin D’s modulation of the immune system makes it important for healthy immune responses. This has even been suggested as playing a role in the degree to which Covid impacts individuals, alongside poor metabolic health. (1,2,3)

So, vitamin D is pretty darn important for your health! But what is the best way to maintain optimal levels of this important compound? I have noticed a narrative that sun exposure where I live (in northern Canada) isn't adequate, that it's basically impossible to get sufficient levels of vitamin D from the sun, and that we must supplement it year round to be healthy.

But does this make any sense intuitively? From an evolutionary standpoint? Would hunter gatherer tribes and our ancestors have been better off if they had a good vitamin D supplement in the winter months? Would nature do us ‘oh so wrong’ like that? Or would the intelligence of nature have controlled for that somehow?

Could it be more likely that our Westernized lifestyle, and misinformation about the dangers of sun exposure are what's resulting in the chronically low vitamin D levels our population is considered to have? If individuals ensured they got consistent sun exposure (when the opportunity of a beautiful sunny day arose), and they focused on improving their metabolic health, might we actually store enough vitamin D in our bodies to account for the lack production surrounding the winter months? Then, would we need to be supplementing vitamin D all year? Just in the winter months? At all even?

  • I am not arguing that vitamin D supplementation is useless or that it doesn't have a place in healing and health.

  • Supplemental vitamin D has been shown to improve IBS symptoms, decrease thyroid autoimmunity, and may help with the winter blues, but again, the sun will offer those same benefits and more! (A. Abbasnezhad et al. 2016) (Elias E Mazokopakis et al. 2015)

  • Of course vitamin D supplementation is still going to be better than doing nothing if you are not able and willing to get out in the sun every opportunity. Maybe the structure of your day makes it challenging or uncomfortable to do so. Many people don't want to go outside on their lunch break in a public space and have a bunch of skin exposed, or don't want attention drawn to them like that, and that is an understandable choice. But it will always be in your best interest to choose to receive the profound benefits of the sun.

  • It's troubling to see people trying to cheat nature with supplements. By supplementing vitamin D INSTEAD of actively getting sun exposure, you are only cheating yourself, your health, and you're cheating the world of your true potential when your health is optimized. Here is why:

The Benefits of the Sun (beyond vitamin D production):

  • Cancer protection!

  • Sunlight offers cancer protective benefits separate from anything to do with vitamin D levels.

  • Chronic exposure to sun was required to receive the anti-cancer benefits in the European Journal of Cancer’s systematic review published in 2013.

  • A 2016 Dermato-Endocrinology data review showing association between sun exposure and cancer concluded for all invasive cancers that in 11 of 22 leading cancers, incidence was significantly decreased with sun exposure.

  • Sun exposure protects against invasive cancer and half the most common cancers.

  • The review also found no association between sun exposure and melanoma of the skin.

  • Sun exposure then, may help prevent cancers that are far more dangerous and common than skin cancer.

  • Avoiding the sun may result in being twice as likely to die from all causes! Studies done on Swedish women showed those who avoided the sun were twice as likely to die from any cause vs the sun exposed women, with no increased risk of skin cancer for the sun exposed women.

  • Sunlight profoundly impacts your circadian rhythm (your body's internal clock) and all of your body's metabolic functions. (1,2,3)

  • Sun exposure may cause the release of endorphins and makes you feel fabulous. (Who doesn't like to feel fabulous?)

  • Although this study was done on mice, you may find this to be subjectively true.

  • Perhaps it has been your experience that sunny days generally make you feel happier and more positive?

  • Tying in to the last point, this study done on humans showed sun exposure improving symptoms of depression.

  • Sun exposure also stimulates nitric oxide in the body. Some benefits of nitric oxide include:

  • Nitric oxide causes vasodilation (dilates blood vessels), lowers blood pressure and increases blood flow, helping protect you from heart disease. (Russo et al., 2017)

  • Nitric oxide aids in relaxing pathways to alveoli in the lungs- allowing greater transfer of O2 into the blood. (Whittington et al., 2018)

  • Nitric oxide is highly effective at defending against pathogens- bacteria, fungi, parasites. (Schairer et al., 2012, p. 1)

  • Sun exposure can protect against digestive tract disease and inflammation.

  • IBD/Diverticulitis specifically. (Lillias H. Maguire et al. 2015) (B.N. Limketkia et al. 2014)

  • Sun exposure can decrease the occurrence of eczema. (Andrew Stewart Kemp et al. 2013)

  • Overexposure could increase your skin cancer risk, but that might involve tanning bed abuse, chronically spending hours and hours exposed to the sun, and receiving chronic sunburns.

  • So just don’t go crazy with the sun exposure and ensure you are exposed to a reasonable amount during what I call the Vitamin D Witching Hours (12:00-3:00). Your shadow will be shorter than you are tall.

  • Expose yourself just long enough for a bit of skin pinkness, avoid burning, and you should be getting the “full spectrum” of sunlight benefits, including vitamin D synthesis, plus a sexy looking tan.

  • I like to get between 15-30 minutes of mindful exposure whenever the opportunity (a warm sunny day) presents itself.

  • Other considerations for sun exposure and vitamin D synthesis:

  • SPF 30 sunscreen reduces vitamin D synthesis by 95+%

  • Dark skinned people may need 3-5 times longer sun exposure than light skinned people to produce similar amounts of vitamin D.

  • Obese individuals may need 2 times longer sun exposure than a lean person.

  • Various other considerations (and more) can be found at this site.

How does vitamin D supplementation hold up against Father Sun for health benefits?

  • In short, it doesn't!

  • Low vitamin D is associated with several diseases, and supplementing vitamin D to raise the levels has not appeared to provide the predicted improvements when studied. (E.Theodoratou et al.2015) (Philippe Autier et al. 2014)

  • It seems that vitamin D supplementation cannot compete with actual sunlight exposure for both vitamin D synthesis and accompanying health benefits.

  • To me this makes logical sense, as healthy people who don’t spend much time outside exposed to sunlight are non-existent in my experience.

  • Low vitamin D is more likely a marker of poor health from a Westernized diet and lifestyle rather than a cause of poor health.

  • I hypothesize that the general prevalence of vitamin D deficiency is more to do with a lack of purposeful sun exposure and the prevalence of poor metabolic health in our population, rather than it being "impossible" to get optimal amounts due to living in our northern latitudes.

  • Perhaps if everyone took the time to get sun exposure when the opportunity arose, and learned to eat/live in a way that promotes optimal metabolic health, the narrative of requiring vitamin D supplementation year round (or even at all) would cease to exist.

  • Emphasizing mindful sun exposure, and shifting away from a Western diet and lifestyle to improve your vitamin D status, rather than taking a vitamin D supplement, will profoundly improve your health.

"Be skeptical, but learn to listen"- Don Miguel Ruiz
  • In general, research can be found to support almost any claim.

  • With that in mind, don’t take my word for it. Instead, experiment with getting more mindful sun exposure and determine if what I am putting forth is true.

  • Find out for yourself if you feel better actively getting sunlight sourced vitamin D vs supplemental vitamin D.

  • In the end, supplementing vitamin D instead of actively getting sun exposure when you can is trying to hack nature. You will likely find your health improves significantly more when you work in harmony with nature instead of trying to trick or manipulate it.

  • It is in your best interest to prioritize getting out in the sunshine and receive healthy exposure to your bare skin. As we have learned, vitamin D is merely a drop in the bucket of the suns full benefits.

  • Please take the time and make the effort to step outside and have a hang with Father Sun and his healing light; the light he unconditionally gives to everyone and everything. The sun's rays are always free, and totally indiscriminate of everyone and everything on Earth (what better representation of unconditional love?). The sun’s effects on your health are truly profound. Mindful, proactive sun exposure is an act of self love. You would be doing yourself and the collective a great disservice not to utilize this important component of optimum health!