Vitamin D From the Sun and the Benefits of Sun Exposure

There are few topics as controversial as safe sun exposure. Sunbathing and tanning often get a bad rap, but mounting evidence reveals that moderate sun exposure is not only safe but necessary. In fact, the most recent in-depth review found that avoiding the sun was similar to smoking as a risk for all-cause mortality. Put simply, avoiding the sun may be as dangerous as smoking cigarettes!

Is Sun Exposure Safe?

First, let’s collectively pause and take a deep breath. As I mentioned earlier, this is a controversial topic. I’m just here to share insights gleaned from personal research and blood tests conducted on myself and my family. 

Let’s also remember that anecdotal evidence doesn’t prove anything. Here are a few examples:

  1. You know someone who died from skin cancer, so you think all sun exposure is bad. (Even though science doesn’t back this up and that scenario doesn’t prove causation).
  2. You know someone who has been outside every day of his or her entire life and got sunburned all the time. Yet, they never got cancer; so, all sun exposure is safe. (Science also doesn’t back this up).

We all know people who have been affected by cancer and I’m sending hugs to all of you who have lost someone to this dreaded disease. However, knowing someone who died of cancer doesn’t equal a scientific study. I know someone who has gotten very little sun exposure, wears a hat and sunscreen daily, and still got skin cancer on his nose. This example is also not scientifically relevant.

A lot also depends on your skin pigmentation. As someone of Northern European descent, I have less melanin in my skin. So, I likely need less UV exposure to produce vitamin D than someone with darker skin. The current evidence shows that some sun exposure is safe for the vast majority of people. However, depending on skin color some people need more sunlight than others to maintain adequate levels of vitamin D.

Ironically, some research suggests certain sunscreen ingredients can increase skin cancer risk. But read on…

Sunscreen, Sunburn, and Skin Cancer, Oh My!

In the last several decades, the push to use sunscreen and limit exposure to the sun has gotten stronger. It’s now possible to find sunscreen with an SPF of 100! Thanks to massive public health campaigns, most people are at least mildly aware of the “dangers” of sun exposure.

Surprisingly, sun exposure might not be as risky as we think. In fact, steering clear of the sun might be riskier than getting some moderate sun. Even though we’re told to wear sunscreen and avoid too much sun, skin cancer rates, especially melanoma, keep increasing.

Skin cancer rates are rising by 1.2% annually (2010-2019), even though we spend less time outdoors and wear more sunscreen. We’re doing the things we’re “supposed” to do and yet, the problem is getting worse.

But is Sun Exposure the Reason?

Here’s where things get interesting… Perhaps the problem isn’t lack of sunscreen or even sun exposure at all, but a deeper cause. A 2023 scientific review found that while sunburn is harmful, moderate non-burning sun exposure has many benefits. That was without wearing sunscreen.

A few of the benefits listed in the review include:

  • A significant decrease in blood pressure in those with hypertension
  • Improved symptoms in those with chronic kidney disease
  • Reduced inflammation
  • Lower rates of cardiovascular disease
  • Reduced skin conditions like eczema

Scientists are now focusing more on the benefits of sunlight and the risks of not getting enough sunlight. In essence, not getting enough sun can be as or more detrimental than excessive sun exposure. As with many aspects of life, it’s the dose that makes the poison.

And Sunscreen May NOT Help Avoid Cancer

Many people believe that since sunscreen prevents sunburn, it must also stop skin cancer. But research doesn’t back up this idea.

Not only does sunscreen not prevent skin cancer, it may actually block some of the most beneficial aspects of sun exposure. While it may prevent or reduce sunburn, it can also inhibit the body’s ability to produce vitamin D from cholesterol in the skin cells.

Vitamin D deficiency is already at epidemic levels, and it’s been that way for a long time. As of 2010, over a billion people worldwide were deficient or insufficient in their blood levels of vitamin D.

A 2016 review concluded: “We can find no consistent evidence that use of chemical sunscreens reduces the risk of melanoma.” The review authors even went on to suggest that sunscreens carry a warning label!

This review also stated that: 

“Since public health authorities recommend liberal use of sunscreens for good health, the labeling of sunscreens should contain a statement about the possibility of vitamin D deficiency that may result from excessive use of sunscreens. Labeling should also state that sunscreens have not been shown to be effective in reducing the risk of melanoma.”

Another study in the Journal of Clinical Pharmacology and Therapeutics came to a similar conclusion:

“Sunscreens protect against sunburn, but there is no evidence that they protect against basal cell carcinoma or melanoma. Problems lie in the behavior of individuals who use sunscreens to stay out longer in the sun than they otherwise would. Vitamin D inhibition is, at this stage, unlikely due to insufficient use by individuals. Safety of sunscreens is a concern, and sunscreen companies have emotionally and inaccurately promoted the use of sunscreens.” 

Still, avoiding sunburn is a good idea. It’s the idea that sunscreen is the best way to do so that’s up for debate.

Sunscreen DOES Block Vitamin D From the Sun

We know sunscreen can inhibit our natural production of vitamin D, especially when used regularly. Sunscreen helps to block ultraviolet B (UVB) wavelengths, which are what the body uses for vitamin D synthesis.

As a society, we often stay away from the sun, even though our bodies require sunlight to make vitamin D naturally. Then we use sunscreen, which contains chemicals, to try to lower the risk of one cancer (skin cancer).

Paradoxically, this habit could result in vitamin D deficiency and raise the risk of many chronic health conditions. The mentioned study demonstrated that sunscreen doesn’t actually prevent melanoma.

Why Safe Sun Exposure May REDUCE Cancer Risk

The most comprehensive current studies don’t recommend avoiding the sun. On the contrary, the recent review proposed changing the public health advice to recommend non-burning sun exposure for everyone. It should be enough that their blood levels of vitamin D stay at least 30 ng/mL throughout the year.

The review also found that sunbathing without burning seemed to reduce the risk of melanoma. On the flip side, sunburns were linked to twice the risk of melanoma. While it’s crucial to avoid sunburns, moderate sun exposure may lower the risk of melanoma. 

Another surprising realization from the study was that long term sun exposure may protect the skin. Non-burning sun exposure over time may protect against sunburn as well as melanoma. Researchers thought it might be because the skin adapts to the sun, increasing melanin and becoming thicker. Higher levels of vitamin D may also play a part in the protection.

Vitamin D may reduce cancer risk. The review study specifically found that vitamin D from UVB exposure converts to the active form in the liver. Increasing vitamin D is known to enhance DNA repair, lowering cancer risk. 

To sum it all up, staying out of the sun may be behind the rising skin cancer rates. The review found that it’s unlikely that sun exposure is why more people are getting cancer. In fact, the opposite may be true. Melanoma incidences are probably going up because of vitamin D deficiency. 

Because people aren’t building up their sun exposure over time, they’re not as protected when they are exposed to the sun. Then they’re more likely to get sunburn, leading to DNA damage. 

Common Claims About The Dangers of Sun Exposures

Besides cancer risk, here are some other common claims about the dangers of too much sun exposure (and my response): 

Rapid Aging

We often hear that too much or unprotected exposure to ultraviolet (UV) radiation speeds up skin aging. That’s because excessive UV can harm the skin’s elastin fibers and collagen. This results in fine lines, wrinkles, dark spots, and sagging skin. 

However, it’s important to consider sun exposure within the context of diet and lifestyle. Those who have a high level of oxidative stress from other sources are likely to be more affected by photoaging.

The red light and near infrared radiation from the sun may actually benefit the skin. Photobiomodulation, as it’s often called, is considered anti-aging. In low doses, sunlight increases circulation and supports collagen production.

Eye Damage

Most commentary on sun exposure and eye health emphasizes the dangers rather than the benefits. Headlines emphasize the damaging effects of UV radiation on the eyes. They warn about the development of cataracts and macular degeneration. Then they tell us how important it is to wear sunglasses that block both UVA and UVB rays. 

However, sunlight also has positive effects on the eyes. Exposing the eyes to UV light without sun protection may improve retinal health, increase tear production, and reduce eye inflammation.  

Other Health Benefits of Vitamin D From the Sun

A Better Sense of Well-Being

Getting out under the sun’s rays may also support your mental health. Sunlight stimulates the production of serotonin, a neurotransmitter that supports feelings of happiness. 

In scientific studies, adequate sunlight exposure is linked to improved mood. It may help alleviate seasonal affective disorder (SAD), a type of depression.

Serotonin is also a precursor to melatonin, a hormone that plays a key role in regulating your circadian rhythm. Without a healthy sleep-wake cycle, it’s difficult to get restorative sleep, which is so important for a healthy immune system.

Cardiovascular Health

Moderate sun exposure may also reduce the risk of diabetes, high blood pressure, and heart disease. It may work by increasing vitamin D, lowering inflammation, improving the mood, or even enhancing nitric oxide production. 

Sunlight stimulates nitric oxide production in the skin, which then supports circulation. Improving blood flow can reduce the risk of high blood pressure and atherosclerosis. These two scenarios are major risk factors for cardiovascular disease.

Bone Health

Vitamin D helps the body absorb calcium and phosphorus. These two minerals are necessary for bone mineralization and overall health. They’re also essential for maintaining strong, cavity-resistant teeth.

Studies have linked low vitamin  D with bone diseases like osteomalacia and osteoporosis. Sufficient vitamin D levels can lower the risk of osteoporosis and fractures, in older adults.

Skin Health

Consistent exposure to small doses of UV light may help certain skin conditions. Moderate sun exposure stimulates the production of collagen, a protein that provides structure and elasticity to the skin.

Researchers have found improvements in eczema, psoriasis, and acne with sunlight exposure. The anti-inflammatory effects of sunlight, along with the production of Vitamin D, may be the reason. 

Sunlight can also enhance the body’s ability to heal wounds. Besides supporting collagen, it can promote the production of growth factors and enhance immune function. This can help alleviate symptoms and accelerate the healing process.

Benefits of Sunshine at Different Times of Day

The time of day you’re exposed to sunlight makes a difference. The benefits vary based on whether you’re getting morning, afternoon, or evening sunlight.

Benefits of Sunshine in the Morning 

Exposure to natural light in the morning may increase daytime alertness and focus. It can also help synchronize the body’s internal clock with the external environment. This circadian rhythm is crucial for many physiological functions, including hormone regulation. 

Getting sunshine in the morning can also promote a more consistent sleep-wake cycle, leading to better overall rest. It can help you feel sleepy when you’re supposed to in the evening. No staying up to read or binge TV series!

Some studies suggest morning sunlight has additional health benefits. Because it enhances the health of our mitochondria, it may reduce the risk of chronic diseases. The cardiovascular and immune systems are highly dependent on those energy-producing organelles. 

I try to always start the day with morning sunlight (and getting hydrated) and I’ve really noticed the difference since starting this habit!

Benefits of Sunshine in Mid-Day 

According to Dr. Andrew Huberman, getting sunshine in mid-day supports an elevated mood and healthy hormone levels. Getting sunlight exposure at this time can support healthy testosterone levels in men and estrogen levels in women.

In a 2021 study, men who got 20 to 30 minutes of sun 2 to 3 times a week over a month had significantly higher levels of testosterone. Researchers found that the sun activated a gene in skin cells. This gene then triggered the pituitary and hypothalamus to enhance hormone production. 

The effects weren’t limited to testosterone. The increased FSH and LH released by the pituitary gland also stimulated the production of estrogen (estradiol) and progesterone in women, helping to normalize hormone levels.

Benefits of Sunshine in the Evening

Evening sun exposure reinforces a normal sleep-wake cycle through the higher red light exposure. Getting sun around sunset increases your exposure to red and near-infrared light. If your shadow is taller than you are, you’re getting the ideal levels of those wavelengths.

Be sure not to expose yourself to artificial bright light in the evening, as it can mess with your sleep, motivation levels, and mood.

Vitamin D is Important for Pregnancy, Babies, & Kids

Getting enough vitamin D is also a big deal during pregnancy and nursing. Healthy blood levels of vitamin D may reduce premature labor and other complications. On the other hand, low vitamin D levels can put a mom at higher risk for gestational diabetes and can lead to other problems for the baby.

Pregnancy & Vitamin D

This article from the Vitamin D Council explains the importance of vitamin D for a growing baby. It’s best for vitamin D to be above 30 ng/mL during pregnancy. Some doctors even recommend maintaining levels above 60 ng/mL during pregnancy.

Unfortunately, most women aren’t even close to those levels:

  • Dr. Joyce Lee and colleagues at the University of Michigan found that 37 of 40 pregnant women had levels below 40 ng/mL. The majority had levels below 20 ng/mL. Over 25% had levels below 10 ng/mL.
  • Dr. Lisa Bodnar, a vitamin D researcher, found that of 400 pregnant Pennsylvania women, 63% had levels below 30 ng/mL. Further, 44% of the black women in the study had levels below 15 ng/mL. Prenatal vitamins didn’t seem to make a difference.
  • Dr. Dijkstra and colleagues studied 70 pregnant women in the Netherlands. None had levels above 40 ng/mL and 50% had levels below 10 ng/mL. Again, prenatal vitamins had little effect. Of course, prenatal vitamins only contain 400 IU of Vitamin D.

The researchers concluded that at least 95% of pregnant women have 25(OH)D levels below 50 ng/mL. That’s not good! It can mean they’re using up the vitamin D they have quickly and don’t have enough to store for future use. 

These chronically low vitamin D levels during pregnancy can lead to all kinds of complications. Cesarean births, preeclampsia, gestational diabetes, and vaginal infections are all more likely. Low vitamin D can also lead to a higher risk of autism, mental disorders, infections, low birth weight, and organ problems in the baby.

Vitamin D for Infants & Children

Infants and children may also be suffering from vitamin D and sunlight deficiency. Getting enough vitamin D is critical for growing children. We’re not just talking about rickets. A lot of research links adequate vitamin D status in children to better mental and physical health.

If they don’t get enough sun exposure, it’s important to supplement. In a 2008 paper, researchers concluded that most healthy children need to supplement about 1,000 IU of vitamin D3 daily for every 25 pounds of body weight. Otherwise, it will be difficult to maintain enough vitamin D in their systems. Those with chronic illnesses may need even more.

Many kids aren’t even getting a quarter of that on a good day. When they do, it often comes from the less usable vitamin D2, added to foods like breakfast cereals, orange juice, and whole (“vitamin D”) milk.

Our whole family has tested our vitamin D levels (including me — during pregnancy and after). Even with moderate daily sun exposure, we were all low (in the high 20s or 30s). I work with a doctor to test and supplement (while still getting sun exposure) when necessary.

Does Diet Impact Sun Exposure Risk?

Mainstream medicine and media often suggest limiting sun exposure and using sunscreen. Funny how these simple solutions for preventing skin cancer are also highly lucrative…

But at the same time, they’ve ignored any potential role diet might play in skin cancer. Since skin cancer is rising despite the highest sunscreen use in history… it’s time to look at other causes and solutions.

Over the same decades that skin cancer rates have risen, certain dietary factors have also changed. We now eat more cereal grains, omega-6 vegetable oils, ultra-processed foods, and chemical additives. There’s also an overall lower intake of saturated fats, omega-3 fats, and grass-fed red meats, including organ meats.

It’s evident just looking at breakfast. These days, it’s not uncommon for people to have cereal, skim milk, and orange juice for breakfast. It’s a classic example of ultra-processed food, omega-6 oils, and lack of healthy fats. It’s a far cry from bacon, eggs, and coffee with cream that used to be the go-to breakfast menu. 

Increased Omega-6 Vegetable Oil Consumption

Omega-6-rich oils, like canola, cottonseed, “vegetable”, and soybean, are a new addition to our diets. There’s no biological need to consume these highly processed seed oils. There’s some evidence that eating these oils can cause them to be used in place of the saturated and monounsaturated fats in skin. This switch can make the skin more susceptible to disease.

Some studies show high linoleic acid vegetable oils increase the risk of skin cancer and other cancers. A 2011 study published in the journal Carcinogenesis looked at omega-6s vs. omega-3s and skin cancer. This was a follow-up to studies showing skin tissue fat may affect susceptibility to UV damage.

They found that high-fat diets rich in omega-3s seemed to be protective compared to the omega-6 rich diet. The omega-3 diet slowed the development of skin tumors and decreased their size by 80 to 90%. 

Reduced Saturated Fat and Omega-3 Fat Consumption 

As omega-6 oil consumption has risen, the intake of omega-3 and saturated fats has declined. We’ve seen how well that’s worked out for us, but it turns out that it could have a pretty big impact on skin health, too.

The body needs healthy fats, especially saturated fats and omega-3 fats, to regenerate skin tissue. If the body doesn’t get these fats (and many people don’t these days), it will use whatever it has available. It may even use those omega-6 fats, which aren’t the preferred fat for building skin and collagen.

Avoidance of Vitamin D-Rich Foods

Due to the shift away from omega-3s and saturated fats towards omega-6s, we’re decreasing our intake of vitamin D through food. Food sources of vitamin D that Americans avoid or don’t get enough of include fatty fish like salmon and mackerel, cod liver oil, egg yolks, organ meats, and liver.

A drugstore multivitamin cannot make up for the lack of a traditional, nutrient-dense diet. There are plenty of recipes on this website to get you started. Adding salmon and eggs a couple of times a week is an excellent place to start!

Bottom Line: It’s Time to Rethink Getting Vitamin D From the Sun

Based on the largest review of evidence we have to date, it’s time to rethink sun exposure. While we’ve stayed away from the sun to avoid skin cancer, our rates of cancer and other chronic conditions continue to rise. By avoiding the sun, we’ve increased our risk of vitamin D deficiency. As a result, rates of all-cause mortality are going up.

Embrace the sun! Just do so at moderate levels, while following a healthy diet and lifestyle.

Sun Exposure: What I Do

In light of this, and so much other evidence, I don’t avoid the sun or use harmful sunscreens. In fact, I make it a point to spend time in the sun daily. I also test my vitamin D levels and take vitamin D supplements in the winter months

While 400 International Units (IU) of vitamin D is the amount of vitamin D typically recommended, it may be too low for some people. I take more than that but do your own research. Vitamin D toxicity is possible if you overdo it. Taking too much vitamin D over time can increase blood calcium levels, which can require hospitalization if they get too high. Getting your vitamin D from the sun is ideal.

I make sure to get out of the sun before getting close to burning. If I get enough sun exposure and want to stay outside, I just cover up and wear a hat. And for the first time in my adult life, my blood concentrations of vitamin D are in the healthy range. I also “eat my sunscreen” by eating a real food diet and taking specific nutrients that help protect the body from the inside out.

This article was medically reviewed by Dr. Lauren Jefferis, board-certified in Internal Medicine and Pediatrics. As always, this is not personal medical advice and we recommend that you talk with your doctor or work with a doctor at SteadyMD.

What do you do when it comes to sun exposure? Share with us below!

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