Health Benefits of the Sun: Why Sunshine Is More Than Vitamin D

A Woman Basking in Bright Yellow Sunlight With Outstretched Arms.
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Unless you’ve been living under a rock the last few years, you’ll have a good idea about vitamin D and the health benefits of the sun.

If not, don’t worry because I’ll go over it for those that may have missed out.

However, the benefits of sunlight are not only down to Vitamin D.

Unknown to many, there are also various other benefits of sun exposure.

So although vitamin D supplementation can be beneficial, it is not a like-for-like replacement for sunlight exposure

Sunshine and Health: Why Is Sun Exposure Important?

A Happy Girl Enjoying the Sunshine.

In our society, we prioritize several lifestyle factors when we discuss the biggest influences on our health.

  • Diet / Nutrition
  • Exercise
  • Sleep
  • Stress

But in my book, there should be a fifth one on there because the benefits of sunlight are just as important.

To summarize recent research; the health benefits of the sun include heart disease prevention, reduced cancer risk, improved blood sugar regulation, and reduced all-cause mortality  (1, 2, 3, 4).

So immediately we can see a significant link between sunshine and health; sun exposure reduces the risk of the worst diseases in modern society.

Benefits of Sunlight: Why Vitamin D is Important

Vitamin D Rich Foods - Eggs, Butter, Mushrooms, Dairy.

Coupled with the media scaremongering and fears about skin cancer, the fact that humans have moved to predominantly indoor life has had a big effect on our health.

Through this step indoors, we are losing the benefits of sunlight.

And the result is vitamin D deficiency.

Just to note – even though it has the name vitamin D, it’s not a vitamin – it’s a hormone.

In the light of this widespread vitamin D deficiency, we are more prone to illness and disease.

In fact, this is such a significant problem that more than one-third of the population are now deficient in vitamin D (5).

Here are some reasons why vitamin D from sunlight is so important:

  • Vitamin D is essential for overall well-being” – it plays a role in bone health and prevention of autoimmune diseases, cancer and cardiovascular disease (6).
  • Almost every condition related to vitamin D insufficiency has a secondary effect on ocular health. Adequate vitamin D levels protect against age-related macular degeneration (7).
  • Lower blood levels of vitamin D increase the risk of many cancers; these include breast, colon, lung, prostate, pancreatic and ovarian cancer (8).
  • In a meta-analysis of studies that included randomized controlled trials, adequate vitamin D levels have the same effect on depression as antidepressants (9).
  • Vitamin D is significantly related to all-cause dementia and Alzheimer’s disease (10).
  • Diabetics showed lower vitamin D levels than control participants. Additionally, all-cause mortality was higher in diabetics with the lowest vitamin D levels (11).

As can be seen, there are many health benefits of the sun – but is it possible to get too much vitamin D?

Hypervitaminosis D: Why Too Much Vitamin D Can Be Dangerous

A Lady Feeling Ill Laying Down on the Sofa.

It’s important to realize that just because something is good for you, it doesn’t mean “the more, the better.”

And this is especially the case with vitamin D, where toxicity (known as hypervitaminosis D) can occur if you take too much.

Specifically, notice I said ‘take‘ – vitamin D supplementation can result in toxicity (12).

On the positive side, one of the benefits of sunlight is that our skin can regulate the amount of vitamin D it absorbs.

The result is that when we have enough, our body will stop producing it; therefore no hypervitaminosis.

Just another of the health benefits of sunlight.

However, if you do decide to supplement with vitamin D then just be aware of taking too much.

Supplementing with vitamin D should also take fat-soluble vitamins A and K into account.

The reason why is that they all have a synergistic effect in the body.

For example, vitamin D helps the body’s absorption of calcium.

On the other hand, vitamin K2 directs this calcium to the skeletal system rather than allowing for deposition in arteries.

Whenever people hear about the benefits of sunlight, their mind turns to vitamin D.

A point often overlooked is that the sun has many more benefits that are unrelated to vitamin D.

Health Benefits of the Sun: #1 Nitric Oxide

A Man Checking His Blood Pressure With a Reader.

A hypothesis in 2010 theorized that the benefits of sunlight on cardiovascular risk also had independent mechanisms.

In detail, they hypothesized that the skin contains bound nitric oxide stores.

Upon the skin’s reaction with UV from sunlight, these stores release into circulation where they exert beneficial effects on blood pressure (13).

This diagram shows the process:

Diagram Showing How Sunlight Releases Bound Nitric Oxide Into Circulation.

Nitric oxide is a vasodilator. In other words; it widens blood vessels (14).

While this was only a hypothesis back in 2010, research in 2014 proved the assumption correct.

Upon exposure to skin, sunlight transfers nitric oxide into circulation and drops blood pressure (15).

As high blood pressure is a significant causational factor in cardiovascular heart disease, this is one of the most powerful health benefits of the sun (16).

The study’s researchers concluded that nitric oxide is an important, so far overlooked contributor to cardiovascular health (17).

Health Benefits of the Sun: #2 Immunity and Inflammation

Diagram Explaining Humoral Immunity.

Inflammation shares strong links to the vast majority of chronic disease (18, 19, 20).

However, a benefit of sunlight that you may not know is that exposure to UV rays downregulates inflammation (21).

With regular exposure to the sun, inflammatory markers (such as C-Reactive Protein) drop.

And during periods when there is no exposure to the sun, these markers begin to rise again.

For this reason, getting sufficient sunlight helps reduce chronic disease risk by putting the body into a less inflammatory state.

Significantly, some dermatologists and public health advice urge that we must avoid the sun’s rays to protect from skin cancer (22).

Could this advice be helping to fuel rising rates of chronic disease?

It’s entirely possible, or even probable.

While there are many health benefits of the sun, inflammation is the significant link shared between cancer, dementia, heart disease, and more.

By urging the public to avoid the sun, skin cancer prevention advice could be doing more harm than good.

So get some sun each day, and decrease the inflammation levels in your body.

Health Benefits of the Sun: #3 Sunlight Improves Eyesight

Diagram Illustrating the Visual Conditions of Myopia and Hyperopia.

Another key benefit of sunlight relates to eyesight, and again this is independent of vitamin D.

To explain further, myopia (nearsightedness) is an increasingly prevalent condition that affects approximately 1.5 billion people globally (23).

And to give an insight into the magnitude of this problem; unfortunately, this prevalence rate is expected to reach 4.7 billion people by 2050 (24).

Myopia is especially problematic in East Asian countries such as China and Korea, where children spend much of their time indoors studying (25, 26).

In fact, up to 90% of Asian schoolchildren suffer from myopia.

In contrast, spending time outdoors reduces the risk of myopia. In research done on the topic, the more time outdoors, the more the risk decreases (27, 28, 29).

Myopia results from the eye growing excessively.

Usually, a chemical known as retinal dopamine regulates this growth.

However, when the levels of dopamine drop too much this homeostasis is lost, and the eye can experience uncontrollable growth.

On this note, another of the health benefits of the sun is that sunlight boosts retinal dopamine levels.

As a result, this helps prevent the development of myopia (30, 31).

And for the western world, as long as we keep spending less time outdoors and more time indoors, this trend will only continue.

So to protect your eyesight, it’s a good idea to listen to what your parents probably told you as a child; play outside!

Is Sun Exposure Dangerous?

A Man Tanning in the Sun and Spraying Sunscreen On His Body.

So, now you know the health benefits of the sun maybe you are wondering about the dangers?

Personally, I believe that while sunburn is dangerous for health, just regular sun exposure is not.

With much of the world deficient in vitamin D, it’s important to get some of the sun’s rays to up your blood levels of the hormone.

As can be seen from many studies, getting burned by the sun is a risk factor for skin cancer (32, 33, 34, 35).

Although this may be true, just sun exposure appears to have an inverse connection with melanoma – the most dangerous of all skin cancers.

In particular, several research studies discovered:

  • Inverse associations between longer occupational sun exposure and melanoma; spending lots of time in the sun did not increase the risk (36).
  • Studies show a recreational link between melanoma and time in the sun, but not an occupational one (37).
  • Increasing evidence that sunlight exposure plays a protective effect against skin cancers, including melanoma (38).

Looking at this evidence, it seems to support the fact that overall sun exposure is not the problem.

People spending time outdoors only occasionally (a hot day at the beach) are much more likely to burn than someone who works outside every single day.

Final Thoughts

In short, there are many benefits of sunlight, and some of these boost our health independently of vitamin D.

The totality of the data is clear in that exposure to sunlight reduces the risk of almost every chronic disease in the book.

As a result, we should make sure we take the time to enjoy outdoor life.

Whether that’s going for a walk, a swim at the beach, playing with your children or walking your dog – just make sure you get a bit of sun each day.

That said, just be cautious not to burn.

But at the end of the day, the health benefits of the sun far outweigh the potential dangers.

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