It’s no secret that regular sun exposure is good for your health.
In fact, a recent study found that sunshine can prevent:
Anxiety and depression
It also supports immunity, sleep and brain function. (1)
However, too much sun, especially early in life, can increase the risk of skin cancer.
So the question is, “How much sun is too much?”
In this article, we dive deep into the science of sun exposure and your health.
Sunshine and Vitamin D
Sunshine boosts the production of all sorts of neurotransmitters and hormones, and it all starts with vitamin D.
Vitamin D is synthesized from sunlight by the cells in your skin.
Unlike other essential vitamins, you can’t get it from food.
Sure, you can take vitamin D3 supplements, but sunlight is the best source.
Risks of Sun Exposure
The link between sun exposure and cancer isn’t as clear as you might think.
Too much ultraviolet radiation (UVR) can penetrate the skin, damage your DNA and cause skin cancer.
However, too little sun exposure can actually cause other types of cancer, but more on that later…
On the flipside, research shows that taking vitamin D3 supplements can reduce the risk of these cancers by 50 to 77 percent. (2)
How Much Sun Exposure Is Too Much?
Unfortunately, scientists don’t have exact recommendations for sun exposure.
In general, anywhere from 5 to 15 minutes of direct sun exposure, three times a week, is enough.
With that said, how long you should stay outside depends on several factors, including:
Time of day
Health of the ozone layer
In general, pale skin burns more easily.
At the same time, kids and adults under 20 need to be extra careful.
Research shows that getting sunburns at this age can greatly increase the risk of skin cancer.
For example, a study in the Journal of the National Cancer Institute found that childhood is the highest risk time. (3)
You’re more likely to get burnt between 10 am and 4 pm because the sun’s rays are more direct.
People living at higher elevations, like Denver, Colorado, are also more at risk.
Other areas, like Australia and New Zealand, are located in an area where the ozone layer is damaged.
If you’re going to be outside for longer than 15 minutes, always wear sunscreen (SPF 15 at least).
Protective clothing like hats, long shirts and pants also helps.
After being cooped-up all winter, it can be tempting to go on a suntan marathon at the first sight of sunlight.
However, this is when your skin is most sensitive and has a higher risk of burning.
The Science of Sunshine, Hormones and Your Health
Now let’s take a closer look at how your skin turns sunlight into essential nutrients.
1. Vitamin D
The skin makes vitamin D through a photosynthetic reaction with UVB radiation.
In a way, it’s similar to how plants use sunlight.
This reaction depends on how many UVB photons penetrate the skin.
Several factors affect vitamin D production, including:
Excess body fat
The process of turning sunlight into vitamin D starts in the skin and continues in the liver and kidneys.
2. Serotonin and Melatonin
Serotonin and melatonin regulate the sleep-wake cycle.
During the day, you produce serotonin, but at night those same cells make melatonin instead.
What triggers this change?
Yep, you guessed it…
This is why you should get direct sunlight right when you wake up.
It kickstarts your serotonin production.
In fact, sunlight is proven to reduce symptoms of depression, but more on that later…
At the same time, studies show that melatonin can help suppress skin damage from sunburns. (4)
3. Cytokines and T-cells
Exposure to UVA and UVB radiation helps regulate cytokines and T-cells.
What does this mean for your health?
In a nutshell, it means a stronger immune system!
4. Alpha Melanocyte-stimulating Hormone (alpha-MSH)
Exposure to sunshine causes the skin to release alpha-MSH.
Alpha-MSH is a hormone that repairs damaged genes.
5. Calcitonin Gene-related Peptide (CGRP)
CGRP regulates a number of compounds involved in the immune response.
Once again, sun exposure boosts these bad boys.
UV radiation increases endorphins in the blood.
Endorphins are feel-good neurotransmitters that are released in the skin following sun exposure and exercise.
Ultimately, they’re an important part of the stress response.
8 Health Benefits of Sun Exposure
1. Mental Health
The results are in:
Not enough sun exposure is linked to an increased risk of depression and seasonal affective disorder (SAD).
This is why depression is more common in the winter.
Low serotonin is linked to higher rates of depression, but luckily sunlight boosts serotonin.
For this reason, one of the major treatments of depression is light therapy.
Light therapy mimics real sunlight and stimulates the brain to produce serotonin.
Anxiety-related disorders also respond well to this type of treatment.
2. Strengthens the Bones
By boosting vitamin D, sun exposure strengthens the bones.
Low levels of vitamin D can lead to diseases like rickets, osteoporosis and osteomalacia.
For example, a recent study found that:
“Low vitamin D levels will precipitate and exacerbate osteoporosis in both men and women and cause the painful bone disease osteomalacia.” (5)
When vitamin D reaches the intestines, it supports calcium and phosphorus absorption.
As it turns out, both of these nutrients are essential to bone health.
3. Fights Skin Conditions
As we touched on earlier, sun exposure supports skin health.
For example, sunlight boosts alpha-MSH and GCRP and reduces cell damage.
According to the World Health Organization (WHO), sun exposure can also treat:
4. Prevents Cancer
Proper sunlight is essential to cancer prevention.
People who live in areas with fewer daylight hours have higher rates of cancer, including:
Pancreatic cancer (7)
5. Hypertension and Heart Disease
People living at higher latitudes have higher rates of high blood pressure and heart disease.
Researchers think this is due to lower vitamin D levels.
Vitamin D affects hormones that regulate blood pressure and kidney function.
Ultimately, low vitamin D can lead to inflammation in the blood.
This is why sunlight is essential to protecting the heart.
Once again, people who live farther north have higher rates of serious disease.
Research shows that getting enough vitamin D can lower the risk of diabetes.
For example, one study found that vitamin D supplements can reduce the risk of diabetes by a whopping 80 percent! (8)
7. Multiple Sclerosis
Vitamin D from sun exposure can decrease the risk of developing multiple sclerosis (MS).
People living at higher latitudes have higher rates of MS due to less sunlight.
For example, a meta-analysis found that living at a latitude above 37 degrees can significantly increase the risk of MS. (9)
8. Supports Immunity
You might find yourself feeling under the weather if you’re low on vitamin D.
That’s because vitamin D is essential for immune function.
For example, vitamin D deficiency greatly increases the risk of the cold, flu and other upper respiratory infections. (10)
Symptoms of Vitamin D Deficiency
So how do you know if you’re low on vitamin D?
Common signs and symptoms of vitamin D deficiency include:
Slow wound healing
Low levels of vitamin D can seriously affect your quality of life.
Even slightly low vitamin D can have negative effects on energy.
For example, a study on fatigue in female nurses found that 89 percent of them were deficient in vitamin D. (11)
Choosing a Vitamin D Supplement
Especially during the winter months, it’s a good idea to take a vitamin D supplement.
Vitamin D deficiency is one of the most common nutrient deficiencies worldwide.
Older adults with limited sun exposure are most at risk.
If you think you might be deficient, ask your doctor to run a blood test.
They’ll also be able to help you pick the right dosage.
Make sure to buy a supplement that contains vitamin D3 (cholecalciferol) because this is the most bioavailable form.
It should also be free of fillers and other unnecessary additives.
Keep in mind that vitamin D is fat-soluble, so it’s best to take it with fatty foods.
If you have any more questions about sun exposure and vitamin D, feel free to contact us at Complete Care Health Centers.
We’re happy to answer any questions you may have.