Why Vitamin D Supplements Won't Cut It & Sunlight Exposure Fixes The Problem

I know what you're thinking: "Vitamin D supplements are used so widely."

"My aunt, my colleagues, many acquaintances are all taking vitamin D supplements..."

Yes, I know.

I hate to break it to you, but that choice is not optimal.

There's a much better option. The bright side is that the better option is 100% free.

In this article, I'll tell you why vitamin D3 supplements are not the best course of action if you want to achieve optimal health.

So why did everyone get this step wrong?

Simple: we sometimes collectively go in the wrong direction as humanity. 60 years ago, everyone was spraying DDT on their crops, until it was concluded that this pesticide does real harm to you.

The same is true for vitamin D supplements - Sunlight, specifically ultraviolet light, proves to be a much better option...


Why Vitamin D Supplements Won't Cut It & Why You Need Ultraviolet Light From Sunlight Exposure Instead

In today's modern society, almost everyone is low on vitamin D [2].

On the low side, estimates assume that a third of all people are low on vitamin D. Higher estimates are less forgiving, and consider 90-95% of people low on that vitamin.

Those kinds of vitamin D deficiencies are a big problem.

Because of their low vitamin D levels, many people supplement with vitamin D. By doing so, these people assume that supplements can replace sunlight. 

You might make that assumption too...

Taking vitamin D supplements, however, proves to be the wrong health strategy.

The truth is - and this article will make that argument - that you cannot replace vitamin D from sunlight by a supplement. 

The problem with thinking that supplements can replace sunlight, is that sunlight has many additional benefits besides vitamin D creation. 

So if you're not out in the sun, you're missing out on those benefits.

However, many people have additional destructive beliefs around sunlight.

Here are two examples:

Firstly, many people associate sunlight exposure to skin cancer. And secondly, many people assume that sunlight is bad for their health.

Those beliefs are mistaken as well.

It turns out you don't need this to achieve optimal health:

vitamin D supplements

You need this instead:

sunlight exposure at the beach

Yes, you need sunlight.


There's no alternative. This article tells you why - in the following order:

  • First, I'll explain what vitamin D is.
  • Then I'll tell you about my story regarding vitamin D.
  • Next, we'll look into ultraviolet light, and how ultraviolet light creates vitamin D in your skin. I'll also teach you how to maximize your vitamin D creation.
  • I'll subsequently talk about why ultraviolet light - instead of vitamin D - is the real hero of this story. You'll learn that exposing your skin and eyes to ultraviolet light has massive benefits. 
  • Lastly, I'll tell you why UV light is absolutely necessary for many bodily processes - other than vitamin D creation. So, in conclusion, there will be no avoiding ultraviolet light exposure on your body.

You can view the full table of contents below.

Note: this blog post - like my previous blog post - contains some nerd sections. These nerd sections contain more advanced explanations.

You can skip these nerd sections if you just want to understand the basic about vitamin D and UV light.

Ready? Let's begin...

By the way, you can receive my best sunlight exposure tips absolutely free. That way, you can improve the time you spend in the sun.


Table of Contents

What Is Vitamin D?
My Story With Vitamin D3 Supplements And Sunlight
What Is Ultraviolet Light?
How Can I Create Vitamin D?
Why Your Vitamin D Levels Might Be Low
Why Vitamin D Matters For Health
Ultraviolet light: The Real Hero Of This Story
UV Light And Your Eye: Dopamine
UV Light And Your Skin: The Only Addiction You'll Ever Need
Conclusion: The Sunlight Revolution
Remaining Questions


Get 9 More Sunlight Exposure Tips Not Covered In This Blog Post? 



What Is Vitamin D?

You might think of vitamin D as a vitamin - it's in the name right?

Vitamin D, however, mostly has mostly properties of a hormone [65]. Vitamin D is related to thousands of bodily processes affecting your health. Examples of such processes are regulating the calcium in your bones, your immune function, and hormone levels. Simply put, you need vitamin D for optimal health.

You might have heard that Vitamin D is the sunshine vitamin.

That's absolutely true.

And I'll make exactly that argument: that the sun is the best source of vitamin D. 

You might know that food is another source of vitamin D besides sunlight. We'll treat the relation between vitamin D and food soon.

Let's first consider how vitamin D is created from sunlight.

To create vitamin D, the sun needs to be high up in the sky. The sun's rays then need to directly hit your skin, so that your skin can form vitamin D. 

How is vitamin D formed? 

In your skin's surface level - the upper tenth of a millimeter of your skin - cholesterol reacts to sunlight. When that sunlight reacts with cholesterol, vitamin D is produced. 

That vitamin D is transferred to your liver and kidneys. Once processed by your kidneys, that vitamin D is transferred through your bloodstream, to other parts of your body.

My Story With Vitamin Supplements And Sunlight

I confess.

I've told people that vitamin D3 pills are a great supplement in the past. And you know what? For most people, vitamin D3 pills probably do more good than harm.

But vitamin D3 supplements are far from optimal for your health.

That's why I no longer recommend vitamin D supplements. Vitamin D supplements are a half-truth.

You have better options. You'll find out why vitamin D supplements aren't optimal soon enough.

Why are vitamin D supplements a half-truth? Because vitamin D supplements do not lead to optimal health.

Well, on this blog, we're out for optimal health.

You don't just want to be healthy - conceived as the absence of sickness - you want optimal health instead.

Optimal health means having an excess capacity of energy. To give an example of optimal health, it means you should have ample of excess energy to accomplish what you want. Even after completing your daily tasks. Excess energy.

Again: vitamin D supplements do not lead to optimal health.

It's bad enough that vitamin D supplements are not optimal for your health. But vitamin D supplements have an additional problem: they make people complacent.

Many people start to think that taking a vitamin D supplement frees them from having to spend time in the sun.

Because let's be honest: taking a pill is much easier than spending time in the sun.

You nevertheless need to get sunlight exposure for optimal health. Taking vitamin D supplements, therefore, stimulate poor behavior.

But why should you spend time in the sun?

Well, Vitamin D created through your skin is totally different than the vitamin D you get from a supplement.

You'll discover why soon.

But the story gets more interesting.

Sunlight has many other benefits besides vitamin D. Nowadays, I'm making sure I'm getting all these benefits:

Bart Wolbers in sunlight

And I no longer take vitamin D3 supplements.

Since giving up on vitamin D supplements, and getting my skin exposed to sunlight almost every day, a lot changed.

My health skyrocketed.

I've got more energy, my thinking is clearer, and I feel much better in general.

You can have these results too.

Next, I'll tell you how you can best produce vitamin D through your skin, and why that's important. To understand how to create vitamin D in your skin, however, we first need to explore ultraviolet light.


What Is Ultraviolet Light?

Ultraviolet light is different from visible light. Contrary to ultraviolet light, your eye can see visible light. 

How can you understand that visible light? You can simply understand visible light as all the colors that are found on the rainbow. Just imagine the colors violet, blue, green, yellow, orange, and red, and you're set.

You can see all these visible colors on this bird below:

analogy between a bird and different colors of visible light

Two types of light, however, are invisible to the human eye: ultraviolet and infrared light.

In this article, I'll mainly talk about ultraviolet light.

Depending on the place you live, the ultraviolet light emitted from the sun reaches the earth's surface. 

A certain type of ultraviolet light - called ultraviolet B - creates vitamin D in your skin. 

Fortunately, you are already acquainted with ultraviolet light. 

How do I know that?

You probably had a sunburn before in your life. That sunburn occurred because of ultraviolet light.

Too much ultraviolet light exposure causes DNA damage, to which the body reacts. That reaction is a sunburn. Redness and pain are the results of a sunburn.

But how can you understand the relationship between visible light and ultraviolet light?

Well, the sun emits Ultraviolet A (UVA) and Ultraviolet B (UVB), visible light, and infrared light.

Those different types of light are all part of the light spectrum:

light spectrum with infrared visible and ultraviolet light

As you can see, different types of light have different wavelengths. These wavelengths are measured in nanometers. The shorter the wavelength, the higher the energy of the light.

UVA and UVB are located between 280 and 400 nanometers. Because UVA and UVB have the shortest wavelength, they carry the highest energy within the sunlight that reaches the earth's surface. 

(Advanced explanation: UVC that is emitted by the sun generally does not reach the earth's surface. There have been measurements of UVC at certain locations, however, which is disturbing.


However, you may not be able to get UVA and UVB year-round on your body.

UVA and UVB only reach the earth's surface when the sun is higher up in the sky.

In many places, the sun does not move high up enough up in the sky during the wintertime to get UVA, and especially UVB.

So, if you're living in Canada, or Sweden, UVA and UVB are not always present. UVB is mostly present during the summertime.

When UVA and UVB are not present, your body will only receive visible light and infrared light from the sun.

Fortunately, the areas with low UVA and no UVB yield during the wintertime, do have foods that are high in vitamin D.

Examples of high-vitamin D winter foods are wild fish and eggs (and animal brains!).

(Advanced explanation: compared to the vitamin D you create from sunlight, however, the levels of vitamin D are low in these foods. Nature has meant to let your vitamin D levels drop during the wintertime when you are living in northern countries. The higher vitamin D content of the seafood at these locations only partially compensate. During the wintertime, your body alters its metabolism to a temperature-based metabolism [70].)


What's important to understand, is that you have evolved as a human to get UVA and UVB exposure when they are available.

That means you must build up vitamin D during the spring and summer. That vitamin D level - which is stored in your body fat - should last until the end of the winter.

Fortunately, even in the wintertime, UVA is available almost everywhere. UVA should give you a clue why I'm tanning year-round.

Even in the snow:

Bart Wolbers tanning in the snow

You're meant to be exposed to UVA.

Now that you understand ultraviolet light, let's look at how you can optimize the vitamin D creation in your skin.


How Can You Create Vitamin D?

Well, there are a few prerequisites to create vitamin D:

  • First, the UVB light of the sun needs to reach the earth's surface. 
  • Secondly, UVB light needs to reach your skin. 
  • Thirdly, your skin must be able to make vitamin D.

Let's go through these prerequisites one by one.

Do you live in the right place? (does UVB light reach the earth's surface at your location?)

The sun needs to be at around a 50-degree angle from the earth, for UVB to be available.

At the equator, the sun almost always reaches that 50-degree angle to the earth. That means that if you're living at the equator, UVB is present year-round. At the equator, you can therefore almost always produce vitamin D in your skin.

As a rule, the farther you move away from the equator, the less UVB is available.

the tropics with strong sunlight and uvb
The Tropics. Great for year-round vitamin D.


If you're living in the northern hemisphere, however, in countries like the Netherlands, Germany, Canada, or Russia, UVB is not available year round. That means you cannot create vitamin D through your skin year-round.

I live in the Netherlands, so I cannot create vitamin D year-round either.

Nevertheless, if vitamin D is available at your location at this time of the year, noon is the best time around to create vitamin D through your skin.

The best way to find out whether vitamin D is available at your current location is the "D Minder" App. That app is available in an Apple and Android version.

That app really simplifies the sun exposure process for you.

Don't guess whether you can produce vitamin D. Use the app.

(Advanced explanation: the best places to tan are far away from the modern world. Cell towers, WiFi networks, and other devices that put out electromagnetic frequencies, might be able to block UVB rays. Light is electromagnetic as well, so man-made technological electromagnetic frequencies interact with that light. If you want to be safe, get UVB exposure at some distance from "civilization". Equally problematic, moreover, is that air pollution, which blocks UVB as well.)

Next, let's consider how you should expose yourself in the sun.

What do you wear? (Does UVB reach your skin?)

To make vitamin D you need to lose (most of) your clothes. The more clothes you wear, the less vitamin D you produce.

Remember that vitamin D is created only in your skin, when UVB rays hit your skin.

The sun's UVB rays reach can only reach your skin when there's no clothing on that skin.

wearing clothing on the beach so that the skin is not exposed to sunlight
Great clothing style. But too much clothing for Vitamin D creation...


You also need to avoid wearing sunscreen. 

Not wearing sunscreen? You might be asking, "won't I burn?

Yes, you will burn if you stay in the sun for too long. So what you must do instead, is to move out of the sun when you've had enough exposure.

The more often you're out in the sun, the more you'll develop an intuition about when you've had enough sun exposure. For example, I can literally feel when I'm about to get a sunburn and feel that I have to move out of the sun.

If you've had enough sunlight, seek the shade. Cover up with clothing. Wait until the next day. Then repeat.

Is Your Skin Able To Produce Vitamin D?

Several nutrients are needed to produce vitamin D in the skin. Examples are cholesterol, magnesium sulfur, and vitamin A and K.

The worse your diet is, the worse your vitamin D creation. The better your diet is, the better your vitamin D creation.

If you eat a diet that is high in quality fatty acids, grass-fed meats, fatty fish, shellfish, and vegetables, you should get all the necessary nutrients to create vitamin D. Fruits can be added when they are in season

DHA - which is mainly found in fatty fish and shellfish - will help you use sunlight too [64]. To be more precise, DHA is the most important nutrient to use the sun's energy.

in simple terms, just remember to eat fatty fish and shellfish. 

Oysters, mussels, wild salmon, mackerel, anchovy, and herring are great.

Additionally do not wash your skin very heavily after getting exposed to sunlight around noon. 

Washing can destroy the vitamin D that is created in your skin. If you do need to wash, wash your armpits and groin. The upside about ultraviolet light is that it already destroys bacteria, so sunlight will automatically clean your skin.


Why Your Vitamin D Levels Might Be Low

There are several reasons why your vitamin D level might be low. Your levels are probably lower if you're [4]:

  • Wearing sunscreen, which blocks UVB rays. Protection factor (SPF) 8 blocks 95% of all UVB rays, which negate any vitamin D creation. 
  • Born with a darker skin. Dark skinned people need as much as four times as much sunlight exposure to create the same amount of vitamin D. 
  • Not spending enough time in the sun around noon. Getting sunlight exposure in the early morning or evening will not help you create vitamin D.
  • Diseased. Liver or kidney disease can lower your vitamin D creation.
  • Overweight. Excess body fat might reduce vitamin D creation.
  • Of age. Older people are less efficient at vitamin D creation.
  • Pregnant. You need vitamin D for more than one person.

Can you still be optimistic about creating vitamin D in your skin?

Of course! All of these reasons only make it harder to create enough vitamin D in your skin, not impossible. 

So if you're of age, or pregnant, that simply means you need to get more sunlight at noon.

Almost everyone - except for people with serious liver or kidney conditions - is able to make vitamin D with enough UVB exposure.

Again, use the D minder app to be sure.

Remember: you need to build your vitamin D stores during the spring and summer. Not getting enough sunshine during the summer will make it actually much harder to maintain healthy levels during the spring and wintertime. 

That stored vitamin D is used during the fall and winter. Next spring, you're able to create new vitamin D.


Why Vitamin D Matters For Health

In this section, I've summarized scientific literature about why Vitamin D is important. 

This section is divided into two parts. First, we'll look at (preventing) disease in relation to vitamin D. Secondly, I'll tell you about performance and well-being benefits of vitamin D.

In simple terms, I will basically tell you why you cannot ignore your vitamin D needs if you want optimal health.


Preventing disease with Vitamin D

People who have low vitamin D levels are prone to get all kinds of different illnesses. Examples are:

  • Diabetes, heart disease, cancer, bone problems [3; 10; 11; 18; 19].
  • Autoimmune diseases like Alzheimer and Parkinson's [5; 6; 14].
  • Chronic Kidney disease [12].
  • Dental and periodontal problems [13].
  • Immune problems [15; 16; 17].
  • Inflammation and infection [66].
  • Arthritis [28]
  • A common cold [24].

(Advanced explanation: many of the relationships are correlations/associations, while some randomized controlled trials are included. I think, however, that the general pattern is strong enough to imply that there's something to vitamin D for health).

What you can observe, is that vitamin D levels play a role in every area of your health. 

For optimal health, you can thus not avoid optimizing your vitamin D levels. 


Having high vitamin D levels has additional benefits though.

For your athletic performance, for example, optimal vitamin D levels give you higher testosterone levels, lower body fat, increased strength and power, and improved lung function [20; 21; 22; 23; 3031].

Although more research is needed, it is very probable that Vitamin D improves your sleep quality as well - and helps fight depressions [25; 26; 27 ;28].

Oh, and before I forget:

Vitamin D will also make you sexy - preventing hair loss and improving the look of your skin [35; 36; 37].

Vitamin D might even make you smarter [40]...

You basically need sufficient vitamin D levels for performance and a high quality of life.

Let's now return to our UV light story...


Get 9 More Sunlight Exposure Tips Not Covered In This Blog Post? 




Why Ultraviolet Light Is The Real Hero Of The Story

You thought you were reading an article about vitamin D.

That's incorrect.

The real hero of the story of this blog post is actually UV light. Why? It's not just because UV light creates vitamin D in your skin - specifically UVB light.

The health effects of UV light are much broader than vitamin D creation.

What are these health effects of UV light? To begin with, UV light literally enters your skin and eyes. In turn, UV light is physically stored in your body. 

Let's look at that eye and skin. We begin with your eye. Bear with me.


Ultraviolet Light And Your Eye: Dopamine

Have a look at the human eye:

the human eye

What do you see?

Just an organ that allows for vision? That's only half-true.

In reality, the eye is also an organ that allows you to absorb light. Specifically, the eye absorbs UV light. 

Have a look at the anatomical pictures of the eye right below.

Two things are important to notice. They are the pupil and the retina:

anatomy of the human eye

Both the pupil and retina react to UV light from your environment.


(Advanced explanation: firstly, the pupil can be seen as a black body radiator. In simple English, that means that the pupil can absorb energy from photons. The retina, secondly, is a surface area in the back of your eye. That retina has receptors for UV light [58; 59; 67]. Taken together, this information should tell you that your eye is meant to receive UV light input by nature.)


Why does it matter that UV light enters your eye? 

Well, UV light builds dopamine in your brain [53]. 

Dopamine increases your motivation, allows you to think outside the box, and helps you seek challenges in life.

Additionally, UV light also stimulates serotonin and melatonin production [42; 43; 57; 58].

Getting UV light through your eye during the day will help build your melatonin levels at night.

Sunlight during the late morning is necessary for creating more melatonin at night.

In essence, you need UV through your eye for your brain to function optimally. Without UV light, no optimal sleep, no optimal brain function, no optimal well-being.

When dopamine functions well in your brain, instead, you'll be far more capable of decisive action.

You'll move from fear to decisiveness:

daredevil jumping off cliff
 Dopamine in action...


To create more dopamine, you need UV light during the morning when it's available at your location. UV light usually emerges a few hours after sunrise.

But to use that UV light in the morning, you need to stop wearing sunglasses!

Next, let's look at UV light and your skin. You don't want to miss that part.


Ultraviolet Light And Your Skin: The ONly Addiction You'll Ever Need 

All (sun)light that hits the surface of your skin actually penetrates into your body. The exception is UVB, which stays at the surface - as you've already learned.

When ultraviolet light penetrates your skin, it is stored in our body's water. That water is not liquid everywhere, and neither is that water is frozen or in its gas phase.

How can that be?

Most of probably think that water can only assume the solid, liquid, and gas phases.

That's not true...

Water can also form a fourth phase, called crystalline or exclusion-zone (EZ) water.

Your body's cells actually store light in that EZ water [44]. Specifically: ultraviolet and infrared light.

You can see that light as the charge in a battery.

The EZ water is the battery. The Ultraviolet light enters is the charge in that battery.

(Advanced explanation: EZ water has a somewhat different structure, instead of being H2O, its chemical structure is H3O2. One might debate whether H3Oreally is water).

The floating drops are an example of crystalline water.


Why does that battery matter?

Let me explain.

What most people do not understand is that the human body is not just chemical. You're not just a collection of atoms and molecules.

The body is electro-chemical [45; 54].

Electricity plays a major part in your body. That also means that electromagnetism from your environment affects your body.

In plain English, that means that light in your environment can influence the electrical currents in your body as well.

That influence is possible because light is part of that electromagnetic spectrum.

Why does that matter to you?

Well, if you can put more of the right light into your body - specifically sunlight - you can charge your body's battery.

Being able to charge your human battery with UV light means that your body can achieve higher levels of energy.

Vitamin D supplements do not help you to charge that battery.

When you stand in the sun, and you have the right nutrients in your body, this basically happens:

charging up a battery

Now you can begin to see the problem with taking vitamin D supplements. These supplements are not accompanied by an input of light.

Vitamin D supplements basically fake the signal that UVB light is present in your environment.

How can you make your battery work?

You do need to drink high-quality water. Without high-quality water, such as spring water, your body cannot store charge in that water. Fluoride - which is a neurotoxin added to the water in many countries - lowers the absorb-ability of light.

Next, you need to eat fatty fish and shellfish - which supply DHA.

(Advanced explanation: vitamin D supplements cannot simulate Einstein's photo-electric effect. This is because the interaction between photons, transition metals, and electrons in our bodies [68]. The aforementioned DHA is an electron that interacts with light. DHA, as an electron, allows your body to absorb photons from the sun. Photons also affect the electrical current in the proteins and lipids in your cells - as semiconductors. The higher the photonic energy of light (e.g. UV), the greater the discharge as per Einstein's photoelectric effect.

Note that you do need to drink high-quality water for your battery to work. Without high-quality water, such as spring water, your body cannot store charge in that water. Fluoride - which is a neurotoxin added to the water in many countries - lowers the ability of water to hold charge. Bromide in grains has the same effect.)

You know what's even more amazing?

UV light is even taken up in your blood. 

There's evidence that the iron in your blood acts the same way as chlorophyll acts in plants [56]. Chlorophyll allows plants to capture light in their environment, to create energy.

The same is true for your blood. 

That way, UV light can enter your bloodstream to create energy that is used by your cells.

The fact that UV light can enter your blood, is another reason to be wary of vitamin D supplement.

But there's more...

Let's return to the notion that vitamin D created in your skin is different than what you get from a vitamin D supplement. 

Vitamin D has huge effects in our bodies. For example, vitamin D affects which genes are activated and which genes are not [47; 48; 49]. Without being accompanied by the energy of light, vitamin D does not have the ability to influence your genetics [50].


(Advanced explanation: Supplemental vitamin D3 has the "cholecalciferol" form. When UVB hits your skin, vitamin D sulfate is created instead, which reacts with cholesterol. )


You can begin to see that Vitamin D supplements have multiple shortcomings.

But there's more...

UV light on your skin is naturally addictive.

Upon UV exposure, your skin actually produces certain addictive substances that make you feel good [60; 61]. 

Thrill or sex produces the same addictive substances as sunlight.

There are two ways to interpret these findings.

The first interpretation assumes that tanning is dangerous, because you might become addicted to sunlight. That first interpretation is shared by dermatologists around the world. But that interpretation is colored by the faulty assumption that sunlight is bad for you.

Then there's the second interpretation:

The body was made to be addicted to sunlight by nature.

According to that interpretation, you need to feed your sunlight addiction (within reason).

That means you were meant to seek out the sun.

If you do not feed that sunlight addiction, your body will compensate by finding other addictions to compensate. Your body might try to compensate with a phone addiction, watching a lot of television, a drug addiction, alcohol addiction, or sex addiction.

Avoiding your sunlight addiction will make your body look for other ways to feel good.

You thus have to choose your addiction wisely. 

I use this:

strong sunlight and a lake

What's your choice?

By the way, if it's absolutely impossible for you to get enough sunlight during the day, then there's another option.

That option is what is called "red light therapy".

To be sure, red light therapy does not have all the benefits that sunlight has--nothing replaces sunlight exposure for health.

Nevertheless, red light therapy is a simple method by which you can increase your energy levels, well-being, fat loss, beauty (skin, nail, hair quality), and much, much more.

You might be working 12 hours a day and not have the possibility to get outside much. Or you might be working shifts. Or it might be necessary for you to be inside all day when the sun is out.

In these cases, red light therapy can undo some of the downsides of not getting enough sunlight.

In that case, read Alex' full guide on red light therapy. You won't be disappointed...

While red light therapy does not emit any ultraviolet light, it does emit red and infrared light, which are also emitted by the sun.

You'll thus get some of sunlight's benefits from the comfort of your home.

By the way, you can receive my best sunlight exposure tips absolutely free. That way, you can improve the time you spend in the sun.


Conclusion: The Sunlight Revolution

My previous blog post on blue blockers showed that you cannot ignore the light in your environment if you value your health.

This blog post makes that same argument again, but from a different perspective: the sun.

The previous blog post treated blue blocker glasses. Blue blocker glasses help you manage your relationship to light during the night. This article about UV light, helps you manage your light exposure during the day.

The fundamental argument of this article is that you need UV light to achieve optimal health. The vitamin D that comes from UV light comes only secondarily.

That's true whether you live in the city, or in the countryside.

That means you need to get out in the sun during the day to get your UV.

There are two things you should do after reading this article:

  1. Get UV light from the sun into your eyes from sunlight during the morning. No glasses, sunglasses or lenses allowed.
  2. Get UV light exposure from the sun during the noon to create vitamin D, and to gain massive other benefits.

And stop supplementing vitamin D. Charge your battery with ultraviolet light.

Final advanced explanation: this article should also hint at you why our indoor artificial light is so bad: it does not contain any UV. No indoor UV light means lower neurotransmitter levels in your brain. Dopamine, serotonin, and melatonin are some of these neurotransmitters. Without these neurotransmitters, its harder if not impossible to achieve optimal health. The problem gets bigger though: indoor lighting does not contain any infrared anymore as well.


Get 9 More Sunlight Exposure Tips Not Covered In This Blog Post? 



Addendum: My View In 2020:

Over the years I've changed my view on sunlight exposure. I wrote this blog post in 2018, initially, but since changed some of my views. Here they are:


  1.  More sunlight exposure is not better. Less is not better either. There's a golden mean in exposure. I still think you should never burn and get out of the sun ASAP once you turn red.
  2. Much of the physical and biomechanical effects I still agree with. However, I'm less certain of their absolute truth - discussing this dynamic would take tons of time though.
  3. I'm less certain sunglasses and sunscreen (natural!) are always wrong. Read below why.
  4. I still think higher vitamin D levels and more sunlight exposure are perfect methods for most people to improve their health!


Remaining Questions:

Should I ever wear sunscreen?

In principle, sometimes. Sensible sunlight exposure means that you should exit the sun if you've had enough sunlight.

If you're experienced with tanning, you'll feel when you've had enough sun.

A frequent question I get is: "but what if I need to be in the sun?" In that case, make sure you cover up with enough clothing. Clothing prevents the UVA and UVB from penetrating your skin.

There's a second issue with sunscreen: sunscreen actually allow you to stay in the sun for too long. Sunscreen disrupts the feeling that makes you seek the shade - which normally emerges when you've had enough sunlight for the day.

However, if you have to spend all day in the sun, such as on a cruise, then wearing some natural sunscreen (with mostly zinc oxide, for instance), is much better than getting sunburned. 


Should I ever wear sunglasses?

In principle, not necessarily, although there are some exceptions. 

There are only two extreme situations I can think of.

First, you might have gotten totally used to wearing sunglasses. In that case, slowly start exposing your eyes to the UV light. Your body can - and should - re-adapt to UV light.

Secondly, you might in an area that has enormous UV exposure. Examples are areas where you are high up in the mountains, with a lot of snow. The UV exposure can increase 200-300% in those areas. In that case, wear sunglasses to protect yourself from too much UV.


How did humans create vitamin D, if UVB is not available year-round everywhere?

In these periods when UVA and UVB are not available, your human biology shifts to an emphasis on cold instead of light. 

To give an example: let's say you're living in Sweden. During fall in Sweden, there will be no UVB. The temperatures in your environment will also be colder. 

Temperatures--instead of light--will then be the main determinant of your biology.

Only when UVA and UVB re-enter the earth's surface in Sweden, will your biology return to an emphasis on light.

Read Jack Kruse's excellent "Cold Thermogenesis" series if you want more information [1].

I warn you. They are tough reads.


Can I get my vitamin D from food?

You can get vitamin D from food. Fatty fish, eggs, and milk are excellent sources [8].

Cod liver oil is a very poor choice, even though it's generally high in vitamin D. Most cod liver oil on the market is rancid and oxidized.


I'm pregnant! Do I need vitamin D?


Make sure you get enough vitamin D. The great majority of mothers are deficient in vitamin D. [32; 33; 34].

Vitamin D deficiency not only affects your child during pregnancy. Your vitamin D is also transferred to the breast milk - influencing your child even after birth.


Against your advice, I'm taking Vitamin D pills anyway! How do these pills work?

You probably need around 3,000 - 10,000 international units a day. Take vitamin D3, not vitamin D2.

New research demonstrates that the prescribed levels of vitamin D by governments are way to low.

If you have gut issues, the absorption of vitamin D supplements is decreased [38; 39; 40].


Doesn't sunlight cause skin cancer?

No. Experiencing too many sunburns in your life might cause skin cancer. But sunlight will not cause skin cancer per definition[51; 52]. Moreover, high vitamin D levels might even help prevent skin cancer.

So, make sure you exit the sun before you get a sunburn. Slowly build up your skin exposure, if you do not yet possess the intuition to move out of the sun before you burn.

Experienced sunlight fanatics feel when they've had enough sun - at least if you're used to tanning without sunglasses, clothes, and sunscreen.

The infrared from the sun will also condition your skin for sun exposure. Get into the sun early.


Should I test my vitamin D levels?

Yes and no. 

The commonly used tests for your "25(OH)D" status, which is the non-active form.

The active form is called "1,25(OH)2D". 

Test for both if possible.

How should I interpret my vitamin D levels? As a benchmark for UV absorption over the last months.


Can you give me some tips to get more UV exposure?

Sure. There are three main methods:

First, go to a higher altitude. At a higher altitude, UV levels will be much higher. The amount of UV increases 10% for every 1.000 yards of altitude.

Secondly, stay close to the water. The beach is even more perfect. Water reflects about 50% of UV, and sand reflects 20%. That's a 70% increase in UV exposure.

Thirdly, you can buy an aluminum mat. Aluminum reflects 90% of UV. With an aluminum mat, you can make your tanning sessions dramatically more efficient. Make sure you don't burn though.

As I live in the Netherlands, and there are no mountains here, I mostly use the second and third method.


What do you wear when out in the sun?

I wear tan-through swimwear. Tan-through swimwear allows some of the UV light to pass through the fabric, so that your private parts get tanned as well.

You can buy tan through swimwear HERE (I'm not affiliated).


What if it's absolutely impossible for me to get sunlight during the day?

First of all, intend to switch your job over time, or make sure that you can get sunlight exposure anyway in the future.

Secondly, make sure to read Alex' blog post about red light therapy. Red light therapy can mitigate some of the effects of not having enough sunlight exposure in your life. 

Red light therapy commonly uses LED panels to project massive amounts of both red and infrared light at our body, which simulates the morning sun.

Thirdly, take a vitamin D supplement if you cannot get any sunlight at all--although again, that option is sub-optimal.

I have to say it again: nothing replaces real sunlight. 


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This is a post by Bart Wolbers. Bart finished degrees in Physical Therapy (B), Philosophy (BA and MA), Philosophy of Science and Technology (MS - Cum Laude), and Clinical Health Science (MS), and is currently a health consultant at Alexfergus.com. 


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