Why You Need To Get Out Into The Sun

Go Outside. You Cannot Supplement For The Sun!

The sun gives off many wavelengths from gamma rays (huge waves) to extremely low (small) frequency waves. 

As humans, we only perceive the visible spectrum, but there are also benefits of the other parts of the spectrum (the light waves that are produced by the sun). 




  1. Basics
  2. Benefits 
  3. How And When To Get Sun
  4. Why Do People Get Tired From The Sun?
  5. The Problem With Sunscreen
  6. Mechanism Of Action
  7. Caveats
  8. More Research


In common day western society, we are consistently bombarded by artificial light.

Our workspaces are indoors, powered by fluorescent blue lights (which blue has its own negatives).

We only get sun rarely and it’s either partial (such as through glass while driving to work) or too much (single sessions of long periods hanging out at the beach).

We also try to supplement for the sun by taking vitamin D hormone supplements, which is not as bioactive for creating the active form of vitamin D.

So let’s shed some light on the truth about the sun. 


1. Protects Against Cancer



There are many contributing factors to cancer, but many scientists agree that inflammation, dysregulation of the immune system, and mitochondrial dysfunction (the powerhouse of the cell that produces energy) severely contribute to developing cancer.

The sun can decrease inflammation, regulate/improve the immune system, and improve mitochondrial function (all discussed in specific benefits below). R R R 

There are actually studies showing the harmful chemicals in sunscreens can cause mitochondrial damage and inflammation (more discussed below). R R R

And some skin cancers have shown to be more likely to be developed on areas of the body wearing clothes. R

Also there are many studies linking less exposure of sunlight to increased risk of cancer such as colon, pancreatic, breast, bladder, ovarian, prostate, and non-hodgkins lymphoma, whereas increased sun exposure decreases the chance of developing these cancers. R R R

Sun exposure can actually help the survival rate against melanoma and has shown to lower the risk of developing other skin cancers. R R R R R

Ultraviolet (UVA, UVB, and UVC) actually induces cell autophagy (recycling) in the skin, which protects against skin cancer. R

Vitamin D produced from the sun can decrease the chances of many cancers. R

UV (specifically UVB) increases NRF2 (an antioxidant gene), which enhances the body’s natural antioxidant process and has shown to protect against cancer. R R

2. Increases The Body’s Energy

NRF2 also increases mitochondrial function and signaling (communication). R 

Infrared (IR) from the sun can increase mitochondrial function. R

Like chloroplasts (the green parts of plants), mitochondria have the ability to photosynthesize (convert light into energy). R

This overall increases ATP (energy from mitochondria that’s readily available to the body) and cellular respiration (via hormesis discussed below), thus giving you, your body, and your cells more energy. R

3. Sets And Improves Your Circadian Rhythm




Our circadian rhythm (24-hr cycle) is controlled by the suprachiasmatic nucleus (SCN) and other genes. R

The SCN is located in the brain in the hypothalamus and directly connected to the optic nerve in the eye. R

Getting sun first thing in the morning with the sunrise helps activate dopamine (an inhibitory neurotransmitter) release and tells your hypothalamus (via the SCN) what processes to start (such as feeding). R R

Getting bright light with a bright light device in the morning can also help this, but has different benefits (unrelated to circadian rhythm). 

All you need is 15-30min of bright light (from the sun or a device) to reset your circadian rhythm.

UV from the sun helps restore melatonin (the sleep hormone) receptors in your eyes. R

The more time you can stay in the sun during the day, the better your sleep can improve, as you will have more melatonin and mitochondrial energy for sleep. R

Bright light during the day also prevents insomnia, premenstrual syndrome, depression, and seasonal affective disorder (SAD). R

Also getting more sunlight can help you fall asleep earlier. R

Artificial light at night can disrupt the circadian rhythm. R

Blue-light blocking glasses can help with artificial light exposure at night. 

Also, fat tissue under our skin have receptors for UV radiation and can tell the body what time of day it is. R

So having your body exposed to the sun during the day (with less clothing) and covered up in the evening may have benefits on the circadian rhythm and weight gain (see more below). R

4. Increases Vitamin D

Lack of sun can cause low Vitamin D levels. R

The sun helps you produce the active form of vitamin D, which is different than supplementing it (sulfated vitamin D). R R R

Actually, the receptor for vitamin D (VDR) is activated with 1,25 vitamin D (active form) and blocked with 25-D (which is the sulfated version vitamin D). R

This is important since the active form of vitamin D regulates over 1000 genes. R

When UVB (280-320nm) from the sun hits your skin, it starts a reaction to create active vitamin D in the blood and body. R R R

UV can also hit your eyes to produce vitamin D, so wearing glasses, sunglasses, or contacts inhibits this benefit, since UVB cannot pass through glass, but UVA can. R

Optimal vitamin D levels should be around 50ng/mL (40-60 is fine). R R

You can check your levels here. 

5. Increases Mood And Fights Depression



The sun can increase people’s quality of life. R

It can increase amounts of dopamine, tyrosine, and serotonin (two happy neurotransmitters and one precursor to a happy neurotransmitter) in the brain, thus making you happier. R R R R

As discussed before, bright light from the sun can prevent against SAD. R

Using a bright light device can help with this. R

Beta-endorphins (b-endorphin) are released when you look at the sun and when your skin comes into contact with UVR. R R R

B-endorphins are responsible for “runner’s high”. R

The reason why you feel good when going to the beach or lounging by the pool is partly because of the increase/release of b-endorphins.  R R

The release of b-endorphins by the sun actually promotes our natural reward system encouraging more sun exposure. R

Technically in sense of releasing dopamine, tyrosine, serotonin and b-endorphins, UVR exposure can be addictive. R

UV can also reduce levels of perceived stress. R

6. Decreases Pain

Beta-endorphin is also able to decrease pain since it attaches to opioid receptors (the same receptors heroin attaches to). R

Vitamin D can decrease pain from myalgia, myositis, myopathy, or myonecrosis (musle- induced pain). R

7. Improves Cognition and Wakefulness

The sun can also increase histamine and orexin (hypocretin), two wakeful neurotransmitters/hormones. R R

Bright light can also do this. R

On top of having more energy to do things, the sun can increase brain derived neurotrophic factor (BDNF) levels in the brain and nerve growth factors (NGF) in the skin. R R R

BDNF and NGF are necessary for growing new neuronal connections. R R

8. Prevents Neurocognitive Disorders 



BDNF and NGF also protect against developing many neurocognitive disorders. 

There is strong evidence from observational studies that low sun exposure is associated with an increased risk of developing multiple sclerosis (MS), independent of vitamin D supplementation. R

Higher levels of sun exposure may have benefits like improving fatigue for MS through both vitamin D and non-vitamin D pathways. R

UV from the sun is beneficial in MS since it upregulates:

  • T and B regulatory cells R
  • Enhances levels of cis-urocanic acid (which modulates substance P, nuerokinin A, neuropeptide Y, and calcitronin gene-related peptide) R
  • Alters dendritic cell trafficking R
  • Improves Prostaglandin E2 R
  • Increases platelet activating factor R

It also alters cytokines (chemical messenegers) by upregulating IL-10, IL-1B, IL-6, IL-8, GM-CSF, TNF, and IL-33, while downregulating IFN-gamma and IL-17/23. R

Vitamin D deficiency is commonly associated wtih the development of dementia. R

For example, patients that have vitamin D levels lower than 10ng/mL are more likely to develop Alzheimer’s disease (AD). R

AD patients also have problems with the serotonin system and the sun can increase serotonin. R

Lower levels of sunlight exposure are significantly associated with an increased risk for Parkinson’s Disease (PD). R

Also, low levels of vitamin D are associated with PD. R

9. Improves The Immune System And Fights Inflammation

Sunlight is able to fight infections. R

It does this by energizing T lymphocyte cells (cells that play a central role in immunity). R

Blue light from the sun is able to increase the movement of T cells by synthesizing a chemical called hydrogen peroxide, thus protecting against excessive oxidative damage (ie inflammation). R

Vitmain D can also reduce the inflammatory marker c-reactive protein (CRP) and a high white blood cell count. R

10. Protects Against Autoimmunity

As we discussed, UV increases Vitamin D.

Low levels of vitamin D are frequently seen in patients with autoimmune disease, but low levels of vitamin D are probably a result, rather than a cause, of the disease process. R

Chronic disease causes Vitamin D levels to be naturally down-regulated, since there is usually dysregulation of the Vitamin D receptor (VDR). R

Supplementation with extra vitamin D may not only counterproductive but harmful, as it slows the ability of the immune system to deal with immune problems, such as pathogens. R

The sun (specifically UV creating Vitamin D) can dampen the immune system as it: R

  • Decreases monocytes
  • Decreases toll-like receptor activation R
  • Reduces pro-inflammatory cytokines (TNF-alpha, IL-b, and IL8) by increasing IL-10 R

UVB can reduce autoimmunity by suppressing Th1 and Th17 dominant immune responses. R R R

The sun can also increase levels of anti-inflammatory hormones, like alpha-Melanocyte Stimulating Hormone (a-MSH).  R 

A-MSH is also anti-microbial, anti-fungal, protects agaisnt neurodegenerative disorders like alzheimer’s and more. R R R

A-MSH has it’s own myriad of benefits which can be seen here.

A-MSH levels should be at the minimum of 13-85ng/mL.

You can also check your a-MSH levels here. 

11. Enhances The Skin



A-MSH is most recognized for its ability to help you produce a tan via production of melanin. R

A-MSH is commonly low in patients with vitiligo.

Melanin protects us from UV-induced skin cancer. R

UV is able to improve atopic dermatitis (eczema) and psoriasis (via regulation of CGRP). R R

IR from the sun can improve the elasticity of the skin and promote healthy collagen. R

12. Protects Against Allergies And Asthma

Sunlight can reduce the development of asthma. R

UVB improves allergies (IgG and IgE), by suppressing the Th2 immune response.  R

13. Improves the Lungs

Similarly to improving asthma, vitamin D from the sun improves and can prevent the development of tuberculosis. R

Sunlight exposure can also protect against acute respiratory tract infections. R

14. Enhances Eyesight

Melanin not only found in the skin, but also found in the eyes (that’s why are eyes are colored). R

The more melanin your eyes have, the darker your eyes will be. R

High levels of oxygen can be found in the eyes from melanin’s ability to produce oxygen from sun exposure. R

Being indoors has been linked to increasing myopia and poorer eye health. R

Violet, UV, and IR are beneficial for repairing melanopsin in the eyes, which reduces the risk of myopia. R

Sunlight can also improve and prevent blepharospasm, which is an abnormal contraction or twitch of the eyelid. R

Also, vitamin D can improve macular degeneration and myopia. R

15. Enhances Oral, Dental, And Bone Health

Mothers with low levels of vitamin D are at increased risk to give birth to children with cavities. R

Sunlight can create anti-microbial peptides in the mouth that helps regulate oral dysbiosis (an improper balance between good and bad bacteria in the mouth). R

Vitamin D is required for optimal bone health (preventing diseases such as rickets, osteopenia, osteoporosis and oesteomalacia). R

It increases bone mineral density. R

Sunlight can help ameliorate osteoperosis. R

16.  Improves The Cardiovascular System




Low levels of vitamin D are associated with cardiovascular disease. R

The sun can benefit the cardiovascular system in many ways. 

UV in the sun can reduce angiotensin-converting enzyme (ACE), which will lower blood pressure. R

The sun is also able to promote angiogenesis, which is the growth of new blood cells. R

Infrared (produced by the sun) helps create exclusion zone (EZ) water.

EZ water helps the blood transport oxygen throughout the blood system more effectively.

IR also increases nitric oxide release from metals in the body. 

UV also increases nitric oxide in the skin and blood stream. R

The increase in nitric oxide (NO) in the endothelium (wall) of arteries help stabilize blood pressure. R

NO is anti-hypertensive and vasodilative, meaning they help keep the vascular system in a healthy state. R 

NO can reduce circulating triglyceride levels.  R

NO can also help improve erectile dysfunction (ED). R

17. Helps With Weight Loss And Prevents Obesity

Nitric oxide (NO) can also induce the browning of white adipose tissue (WAT) into brown fat (BAT) via increasing genes that promote thermogenesis. R

BAT is fat that has more mitochondria (more energy) and burns more efficiently.  R

Low doses of UV from the sun can reduce weight gain. R

One way it does this is by the increase of aMSH, which suppresses appetite. R

Another way is by sunlight’s ability to increases heme-oxygenase. R

Heme-oxygenase turns heme into iron, carbon monoxide and biliverdin. R

Carbon monoxide inhibits the production of pro-inflammatory cytokines including TNFα and IL-1β, exerting an anti-inflammatory effect. R

Inhibiting these cytokines can prevent the development of obesity. R

Biliverdin can also have an antioxidant effect by reducing bilirubin. R

18. Improves Liver Function




Less sunny regions of the world have higher rates of alcoholic cirrhosis (liver scarring). R

Sunlight on the skin can reduce chances of developing Non-Alcoholic Fatty Liver Disease (NAFLD). R R

Also lower levels of vitamin D are associated with NAFLD, insulin resistance, metabolic syndrome (MetS), and type 2 diabetes. R

UVR suppress NF-κB (and other pathways) which contributes towards liver inflammation. R

For example, UVR can improve insulin resistance and improve fasting glucose. R

It does this by increasing regulatory T cells (Tregs). R

Tregs in WAT improve insulin sensitivity by modulating the anti-inflammatory cytokine IL-10 and the gut microbiome. R

19. Improves Hormones

On top of already producing Vitamin D and aMSH, the sun can increase other hormones.

UV is able to increase sex hormone levels. R R

UV can also increase estrogen levels. R

IR can increase testosterone (and is more effective when the genitals are exposed to IR).  R R

Both UV (via production of MSH) and IR can increase thyroid hormones. R R R R

20. Improves The Gut



The gut expresses a high level of the vitamin D receptor (VDR). R

When vitamin D attaches to the gut VDR, it enhances the epithelial (gut lining barrier), providing protection against pathogens. R

A deficiency in Vitamin D has been linked to inflammatory bowel disease (IBD) and colorectal cancer. R R

21. Enhances Hair Homeostasis

UVB can help grow and regrow hair. R R

It has shown to directly stimulate hair follicle-derived neural crest stem cells to grow, which are important for healthy hairs. R

UVB has been used in treatments for alopecia. R

22. Decreases The Risk Of Dying

In a meta-analysis of 849,000 participants, vitamin D decreased all cause mortality. R

In countries that have less sun exposure (like Sweden and Finland), there are higher (2x) risks of dying. R R

Also, long-term studies have shown sun avoidance can reduce your lifespan (increase all cause mortality) by at least 2 years. R

How And When To Get Sun

The sun works in a hormetic effect, which means a little bit can go a long way and it takes time to build up a tolerance to.

For example, exercise uses a hormetic effect.

In order to run a marathon you wouldn’t run 26 miles on day one.

You would probably start with a mile or two, rest for a couple of days, then slowly increase your ability to run further each week.

That is how you can improve your tolerance to the sun and reduce getting damage (like sunburn) from the sun. 

I was able to raise my vitamin D levels (from 30 to 60ng/mL) and increase my sun tolerance using this method:

  1. Start with 15 min (up to 30) in the morning with sunrise (or a bright light device) to start your circadian rhythm (I like to get the sunrise to hit my neck as well to stimulate thyroid hormones). 
  2. Then during solar noon go out into the sun (I use an app called dminder to tell me when solar noon is based on my GPS location, and how much time I need based on how dark my skin is).
  3. You want to go out as naked (socially acceptable) as possible, and without makeup, so the more skin exposed the better.
  4. Do this every day or every other day, allowing time for your body to rest, produce aMSH (to increase melanocyte proliferation) and produce melanin on your skin – start slowly.

As you build up your skins tolerance via hormesis, you will be able to go into the sun longer.

Since I have built up my tolerance, I am now able to go out into the sun without sunscreen for 4-5 hours without getting sunburnt (on most days).

I use the app Dminder (iPhone Android) to track solar noon, how much vitamin D I am producing, and to track my tolerance to the sun.

Another alternative would be to use the website SunbunMap, but it does not track vitamin D.

If you really cannot get sun (depending on your individual circumstances), at least get a UVB lamp to use at least 15 min/day on various parts of your body. 

At night, make sure to minimize exposure to light (even on your skin and especially to your eyes).

If you are exposed to light in your eyes make sure to wear blue-light blocking glasses.

Why Do People Get Tired From The Sun?

Dehydration mostly, but let me expound upon this.

Acute inflammation like the sharp rise in TNFalpha (which downregulates after exposure) will cause fatigue. R

Also, while prolonged exposure to UV damages your cells, IR can fatigue your mitochondria. 

This creates free radicals, using up your body’s antioxidants, and depleting energy production. 

So, you must first build up a tolerance that enhances your cell’s ability to protect itself. 

The Problem With Sunscreen



So on top of mitochondrial damage and inflammation, as we discussed sunscreen blocks UV and all the benefits that UV can give you. R

There are also harmful chemicals in sunscreen. 

For example, most sunscreens have nasty patented chemicals inside of it and the two I will discuss are BP and 4-MBC. R R

Both of these compounds are estrogenic, which means they bind to estrogen receptors when they shouldn’t. R R

BP is in the form of BPA used to be commonly found in water bottles, but many manufactures have taken steps to remove it, but only from food and drinking containers. R

BP has been linked to cancer and other estrogenic effects. R 

When 4-MBC is applied to the skin, UV from the sun induces 4-MBC to hyper-activate estrogen receptors in the skin.

This hyper-activation is unnatural and has long-lasting effects on the estrogen receptors (kind of like a sticky glue keeping estrogen receptors activated longer than normal).

BP can also hyper-activate the estrogen receptor when you’re exposed to the sun.

There is a myriad of problems with hyper-activation of estrogen receptors, which you can read in this post.

To say the least, hyper-activation of estrogen receptors can contribute to obesity, diabetes, decreased lifespan, cancer, dysregulated hormones, and infertility. R

What To Do Instead



Eating The Sun Diet or supplementing with these supplements should protect against the negative effects of the sun.

Supplementing nicotinamide riboside and astaxanthin are effective ways to prevent sunburn without having to put on sunscreen. R R

I supplement CarotenAll to protect my skin from cancer as well as take sulforaphane to protect against UV-induced skin damage. R R

If you really must need to use sunscreen, using one with zinc oxide would be the best option as it has the least negative effects. R

Mechanism Of Action





  • Sunlight sets the body’s circadian rhythm (sleep/wake/hunger/satiety) .
  • It also decreases inflammation after acutely raising inflammatory markers (via hormesis).
  • Sunlight increases neurotransmitters and hormones that make us feel normal.
  • Downregulates IFN-gamma R
  • Downregulates IL-17/33 R
  • Downregulates TGF-b1 R
  • Enhances levels of cis-urocanic acid (modulating neurokinin A and neuropeptide Y) R
  • Increases aMSH R
  • Increases b-endorphin R
  • Increases calcitronin gene-related peptide R
  • Increases dopamine R
  • Increases NRF2 
  • Increases platelet activating factor R
  • Increases Prostaglandin E2 R
  • Increases serotonin R
  • Increases substance P R
  • Increases T and B regulatory cells R
  • Upregulates IL-1b R
  • Upregulates IL-6 R
  • Upregulates IL-8 R
  • Upregulates IL-10 R
  • Upregulates IL-33 R
  • Upregulates GM-CSF R
  • Upregulates TNFalpha R


If you have histamine intolerance, the sun can increase levels of histamine, which may make reactions initially worse.

Sunlight in the springtime may be correlated with the onset of bipolar disorder (if there is a family history of the disease). R

UV has been shown to deplete carotenoids from human plasma. R

Some studies show that UV can cause photoaging, but it is probably more likely from nutritional deficiencies, rather than the sun. R R

Vitamin D supplementation may exacerbate EBV while its active. R

Vitamin D deficiency is common in all stages of chronic kidney disease (CKD), especially in hemodialysis (HD) patients. R

Two reasons for low vitamin D in HD patients are from low amounts of megalin and high levels of fibroblast growth factor 23 (FGF-23). R


As we discussed above mitochondrial damage only happens when you do not build up a tolerance to the sun’s rays, so it is important to start slow and build up a tolerance.

Cancer and mitochondrial dysfunction from UV exposure can be worse in places where there is damage to the ozone layer and pollution. R R R

More Research

  • Snow reflects approximately 90% of ultraviolet radiation. R
  • UV is strong between 10am-5pm during the summer. R
  • Sand reflects UV approx 15-30%. R
  • Skaters often don’t use sunscreen. R
  • Theobald Palm believed in “sunshine as a means of health”. R