Are you feeling tired, moody, or just not quite like yourself? A surprising number of people are low on vitamin D, which can affect health and well-being. Fortunately, sunlight exposure boosts vitamin D levels naturally. The benefits of vitamin D from the sun are numerous and can help improve overall health and mood, increase energy levels, and promote a longer life. This article will explore how vitamin D from the sun can improve your health and how you can harness the sun's power to feel your best. But, How to Measure Sun Exposure?

One great way to track your daily Vitamin D from the Sun benefits is with SunSeek’s daily sunlight exposure tracker. This easy-to-use tool can help you safely reach your daily vitamin D goals to enjoy this vital nutrient's benefits.

Table of Content

• How Does the Sun Help Produce Vitamin D?

• Top 8 Vitamin D from the Sun Benefits to Energize Your Life

• Download Our App to Track your Daily Sunlight Exposure Today

How Does the Sun Help Produce Vitamin D?

Vitamin D is not one chemical but many. The natural type is produced in the skin from a universally present form of cholesterol, 7-dehydrocholesterol. Sunlight is the key: Its ultraviolet B (UVB) energy converts the precursor to vitamin D3.

In contrast, most dietary supplements are manufactured by exposing a plant sterol to ultraviolet energy, thus producing vitamin D2. Because their function is almost identical, D2 and D3 are lumped together under the name vitamin D, but neither will function until the body works its magic.

The Biological Process of Vitamin D Production

Your body makes vitamin D after the sun's energy turns a chemical in your skin into vitamin D3. This initial product is carried to your liver. Then, your kidneys transform it into active vitamin D. The first stop is in the liver, where vitamin D picks up extra oxygen and hydrogen molecules to become 25-hydroxyvitamin D or 25(OH)D. This is the chemical that doctors usually measure to diagnose vitamin D deficiencies.

Although 25(OH)D is used for diagnosis, it does not function until it travels to the kidney. There, it acquires a final pair of oxygen and hydrogen molecules to become 1,25 dihydroxy vitamin D. Scientists know this active form of the vitamin as 1,25(OH)2D, or calcitriol. Still, for ordinary folks, the name vitamin D is accurate enough.

How Vitamin D Works In the Body

Vitamin D's best-known role is to keep bones healthy by increasing the intestinal absorption of calcium. Without enough vitamin D, the body can only absorb 10% to 15% of dietary calcium, but 30% to 40% absorption is the rule when vitamin reserves are normal. 

A lack of vitamin D in children causes rickets; in adults, it causes osteomalacia. Both bone diseases are now rare in the United States, but another is on the rise — osteoporosis, the "thin bone" disease that leads to fractures and spinal deformities.

The Vital Role of Vitamin D in Bone and Overall Health

Low levels of vitamin D lead to low bone calcium stores, increasing the risk of fractures. It would still be essential if vitamin D did nothing more than protect bones. Researchers have begun to accumulate evidence that it may do much more. Many body tissues contain vitamin D receptors, proteins that bind to vitamin D.

The receptors in the intestines capture vitamin D, enabling efficient calcium absorption. Similar receptors exist in many other organs, from the prostate to the heart, blood vessels, muscles, and endocrine glands. Work in progress suggests that good things happen when vitamin D binds to these receptors. The main requirement is enough vitamin D, but many Americans don't have enough.

Vitamin D Deficiencies and Who Is Most at Risk?

Vitamin D deficiencies were rare when most men rolled their sleeves to work in sunny fields. But that changed as work shifted from farms to offices. Because pigmentation can reduce vitamin D production in the skin by over 90%, nonwhite populations are at particular risk.

Deficiencies are also common in patients with intestinal disorders that limit the absorption of fat and those with kidney or liver diseases that reduce the conversion of vitamin D to its active form, calcitriol (1,25(OH)2D). In addition, certain medications reduce the availability or activity of vitamin D. And even in healthy people, advancing age is linked to an increased risk of vitamin D deficiency.

Causes, Risks, and How to Prevent It

Most experts agree that 25(OH)D levels below 20 ng/ml indicate vitamin D deficiency, while levels between 20 and 30 ng/ml are considered borderline. Limited sunlight exposure is a significant factor, particularly for those living above 37 degrees north or below 37 degrees south of the equator, where UVB energy is insufficient for vitamin D production. People who spend most of their time indoors or use sunscreen may also be at risk for vitamin D inadequacy.

The same is true for people who spend most of their time indoors and those who avoid sunshine and use sunscreens to protect their skin from the harmful effects of ultraviolet radiation. It's an example of an unforeseen consequence of wise behavior, but you can enjoy sun protection and strong bones by taking vitamin supplements.

How Do Sunscreens Impact Vitamin D Production?

Like politicians, doctors often have to compromise; when it comes to sunshine, most pols promise blue skies, while most docs turn out to be the shady guys — or, at least, sunscreen advocates.

Sunlight contains two forms of radiant energy:

• Ultraviolet A (UVA)

• Ultraviolet B (UVB)

UVB provides the energy your skin needs to make vitamin D, but that energy can burn the skin and increase cell damage, leading to cancer. UVA also contributes to skin damage and premature aging.

Sun Protection Tips: Stay Safe with Sunscreen and Proper Clothing

To protect yourself, avoid the summer sunshine, especially between 10 a.m. and 2 p.m. Whenever possible, when you go out in the sun, wear:

• A large-brimmed hat

• A tightly woven, dark-colored long-sleeve shirt

• Long pants

Summer clothing is usually lightweight and exposes a lot of skin. That's where sunscreen comes in. Look for a product with an SPF of 30 or higher. Look for a "broad-spectrum" sunscreen that protects against UVA and UVB. Apply your sunscreen early, often, and liberally.

Widespread Health Issue and Its Impact

These many factors explain why vitamin D deficiencies are shockingly common in the United States. Although standards vary, most experts agree that levels of 25(OH)D below 20 ng/ml (nanograms per milliliter) reflect clear-cut vitamin D inadequacy. In contrast, levels between 20 and 30 ng/ml are borderline.

Using similar criteria, American researchers have reported deficiencies in 42% of African American women aged 15 to 49, 41% of non-hospitalized patients aged 49 to 83, and up to 57% of hospitalized patients. Low vitamin D levels are standard even in healthy young adults; in one study, more than a third of people between 18 and 29 were deficient.

Numbers can never tell the whole story, but in this case, "D-efficiencies" add to a wide range of health concerns.

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Top 8 Vitamin D from the Sun Benefits to Energize Your Life

“Ever since vitamin D deficiency was found to be the root cause of rickets, we have long recognized its role in bone health. Now research is looking at this vitamin as a panacea for numerous ailments, from the common cold, to even cancer,” states Robert Oh, MD, MPH, Chief Wellness Officer of the VA Palo Alto Healthcare System.

As ongoing research peels back the layers of complexity surrounding this vitamin, the scientific landscape becomes dynamic and subject to rigorous debate.

Health Benefits of Vitamin D

Vitamin D is crucial for human health. While primarily recognized for its role in building strong bones, new findings suggest that this fat-soluble vitamin may exert a broader influence throughout the body.

“We now know that the majority of organs and tissues in the body possess vitamin D receptors,” states Rachele Pojednic, PhD, Stanford University nutrition and exercise scientist. “This finding suggests vitamin D has effects beyond the skeletal system, sparking considerable research in the potential benefits of vitamin D for multiple health conditions.”

1. Vitamin D and Bone Health

Vitamin D is key to sustaining the structural integrity of our skeletal system by facilitating the absorption of calcium and phosphorus, the building blocks of our bones.

Through the process of mineralization, these minerals are incorporated into our bones to maintain normal bone density. Inadequate vitamin D levels can result in insufficient mineralization, leading to weakened bones and conditions such as:

• Osteoporosis

• More severe disorders like:

  • Rickets

  • Osteomalacia

Supplementation and its Impact on Bone Health

While the adverse effects of inadequate vitamin D on bone health are well-established, the evidence concerning the impacts of supplemental vitamin D over and above sufficient levels remains inconsistent. In 2007, the US Agency for Healthcare Research and Quality synthesized the research on vitamin D. It determined daily supplementation of vitamin D (≤ 800 IU) with calcium (≥ 500 mg) resulted in slight increases in bone mineral density in older adults.

Additional evidence suggests that vitamin D supplementation lowers the risk of fractures in institutionalized older adults (700-800 IU vitamin D) and female navy recruits (800 IU vitamin D and 2000 mg calcium). Both groups were initially at a high risk of vitamin D deficiency, and their levels were likely insufficient.

Vitamin D Supplementation for Optimal Bone Health

On the contrary, the most extensive vitamin D study to date, Vitamin D and Omega-3 Trial (VITAL) showed that daily supplementation of 2000 IU vitamin D did not reduce fracture risk in more than twenty-five thousand midlife and older adults who had sufficient vitamin D levels on average. The current body of evidence indicates that vitamin D supplementation offers the most significant benefits for deficient individuals.

The benefits of additional supplementation are less clear for those already meeting their vitamin D requirements. This suggests the need to approach vitamin D supplementation for bone health as a targeted strategy—aimed at maintaining sufficient levels rather than striving for excessively high or supramaximal levels. Such a focused approach ensures supplementation benefits those who need it, without unnecessary excess in those already meeting their vitamin D requirements.

The Importance of Preventative Measures for Bone Health

Dr. Pojednic underscores the importance of a proactive approach: "Ensuring sufficient intake of vitamin D and calcium serves as a foundational preventive measure to mitigate bone mineral loss and reduce the risk of osteoporosis later in life.”

This strategy is crucial early in life, as the foundation for peak bone mass, particularly for women, is established in our twenties. By achieving and maintaining optimal levels of vitamin D and calcium from a young age, individuals can maximize their bone strength and preserve it as they age.

2. Vitamin D and Muscle Health

Our muscles need vitamin D to function and develop properly. Studies have established a correlation between deficient vitamin D levels and muscle weakness, pain, and atrophy. 

While the precise molecular mechanisms of vitamin D’s influence on skeletal muscle necessitate further investigation, cell culture studies indicate that vitamin D administration can alter cell pathways related to muscle contraction, cell proliferation, differentiation, growth, and inflammation.

The Impact of Vitamin D Supplementation on Physical Performance

An increasing body of research suggests a positive impact of high and low vitamin D supplementation on physical performance and injury prevention, particularly in vitamin D-deficient adults and athletes. Research has identified a negative correlation between blood levels of vitamin D and biomarkers of muscle damage and inflammation, as well as the number of injuries.

“These findings indicate the potential of vitamin D as a supplement for aiding recovery in injured or overtrained athletes,” states Dr. Pojednic. Further research is required to determine the optimal dosages and interventions for adequate recovery.

Vitamin D and Falls Prevention in Older Adults

It has also been hypothesized that vitamin D may reduce the risk of falls in older adults by enhancing muscle strength and coordination, thus improving balance and postural sway. An analysis of multiple studies indicates that daily vitamin D supplementation may decrease the risk of falls in older adults with low vitamin D levels. This protective effect was not observed in individuals with sufficient vitamin D levels, a conclusion supported by the VITAL trial, which administered 2,000 IU of vitamin D daily.

Vitamin D’s Role in Muscle Health

The current evidence regarding vitamin D and muscle health suggests that supplemental vitamin D's benefits are primarily observed in individuals deficient in the vitamin, mirroring patterns observed in bone health.

It may also benefit athletes and others struggling with muscle damage and recovery. More research is needed to understand the optimal vitamin D level for muscle health and determine whether these levels exceed those required for bone health.

3. Vitamin D and Immune Function

Vitamin D plays a crucial role in immune health, demonstrating various effects on inflammation, autoimmune diseases, and infection rates. The VITAL study revealed that healthy individuals taking vitamin D (2,000 IU per day) were less likely to develop autoimmune diseases such as:

• Rheumatoid arthritis

• Psoriasis

With a 22 percent reduction in incidence over the five-year supplementation period. These protective effects were no longer evident after participants discontinued the vitamin D supplement. This implies that vitamin D needs to be consistently taken for long-term prevention.

Vitamin D’s Impact on Respiratory Health and Infection Risk

In respiratory health, a comprehensive meta-analysis demonstrated that daily or weekly vitamin D supplementation lowers the risk of upper respiratory tract infections, especially in deficient individuals.

During the COVID-19 pandemic, studies revealed that low serum levels are associated with a higher risk of COVID-19 infection. These findings underscore the importance of maintaining optimal vitamin D levels for immune health and the long-term prevention of autoimmune and respiratory diseases.

Supplementation and Autoimmune Disease Risk

“Similar to muscle and bone health, supplemental vitamin D has the most consistent benefits among those with deficient levels at baseline,” states Dr. Oh.

The new findings suggest that supplemental vitamin D may reduce the risk of autoimmune disease even in individuals with sufficient vitamin D levels. Therefore, further research is warranted to identify the optimal vitamin D level for sustaining long-term immune health.

4. Vitamin D and Diabetes

Research has consistently found an inverse relationship between vitamin D blood levels and diabetes risk. Vitamin D deficiency may influence key biochemical pathways involved in developing prediabetes and diabetes, impacting beta cell function in the pancreas and contributing to inflammation.

In a noteworthy observation from the Nurses Health study, women who regularly consumed higher daily doses of vitamin D (>800 IU) and calcium supplements (>1,200 mg) experienced a remarkable 33 percent lower risk of Type 2 Diabetes compared to those with lower doses (400 IU vitamin D, <600 mg Calcium).

The Effect of Vitamin D Supplementation on Diabetes Prevention

Further evidence comes from randomized control trials, which have shown that the benefits of vitamin D supplementation are most pronounced in individuals with low levels of this nutrient. In a randomized clinical trial involving 2,000 adults with prediabetes, participants received daily high doses of vitamin D (4,000 IU) over two years.

The study discovered a significant reduction in the risk of diabetes among those with severely low vitamin D levels. This beneficial effect was not observed in participants with sufficient vitamin D levels.

5. Vitamin D and Cancer and All-Cause Mortality

Epidemiological studies have revealed a connection between insufficient vitamin D levels and an increased risk of cancer and all-cause mortality, prompting significant research into the potential role of vitamin D in cancer prevention and overall longevity. Laboratory studies showcase vitamin D’s ability to inhibit cancer cell growth.

At the same time, epidemiologic investigations suggest that inadequate vitamin D levels correlate with a 30 to 50 percent increased risk of incident colon, prostate, and breast cancer, along with elevated mortality from these cancers. Despite these findings, clinical evidence remains mixed.

Vitamin D Supplementation and Cancer Mortality

The large-scale VITAL study reported a reduction in cancer-related deaths over five years of daily vitamin D supplementation (2,000 IU) but not a decrease in the risk of developing cancer. A recently published secondary analysis of the trial data revealed that participants taking the vitamin D supplement had a 20 percent lower likelihood of developing advanced cancer, defined as metastatic or fatal.

A review of several clinical trials further substantiated the link between low vitamin D levels and mortality risk, broadly showing a seven percent reduction in all-cause mortality with daily vitamin D supplementation (median dose 800 IU).

Further Research on Vitamin D and Longevity

Many unknowns surround vitamin D and its relation to cancer risk and overall mortality. “Significantly more research is needed to determine if low vitamin D levels are a risk factor for cancer and whether supplementation can impact overall longevity,” states Dr. Oh. “Nevertheless, the present data does suggest that individuals at risk for cancer may consider supplementing with vitamin D.”

6. Vitamin D and a Better Night's Sleep

Your amount of daylight exposure is vital in maintaining a normal circadian rhythm, which controls physical, mental, and behavioral changes that follow a 24-hour cycle, responding to light and darkness in the environment, says the National Institute of General Medical Sciences (NIGMS).

The sleep-wake cycle relies on morning sunlight to help you sleep at night. Natural daylight helps your body clock restart to its active daytime phase.

Syncing Your Body Clock

To ensure your body clock is in sync, go outside and get some sunlight when you wake up or turn on the lights in your room. This signals to your body that it is daytime.

Avoid sitting in dim settings during the day. Your body may associate low light with nighttime, disrupting your circadian rhythm. According to Discovery.com, the less morning light you expose yourself to, the harder it will be to fall asleep and wake up at your set time.

7. Vitamin D and Mood

Regular sunlight exposure can naturally increase serotonin levels in your body, making you more active and alert. According to the National Institutes of Health (NIH), exposure to bright light can boost serotonin without the need for drugs. Research shows a positive correlation between sunlight hours and serotonin development, particularly in healthy volunteers.

Sunlight for Seasonal Mood Enhancement

In a study with 101 healthy men, researchers found serotonin turnover in the brain was lowest in winter and highest when subjects stayed longer in sunlight. The findings suggest that spending time in the summer sun can help avoid the winter blues.

Seasonal affective disorder (SAD) and mood variations have been linked to sunlight exposure, with vitamin D3 production playing a key role. Dr. Timo Partonen and his team found that blood levels of cholecalciferol (vitamin D3) are lower in winter. At the same time, sunlight in summer helps your body store vitamin D3, contributing to higher serotonin levels.

8. Vitamin D and Blood Pressure

Skin exposed to ultraviolet (UV) rays releases nitric oxide, which helps lower blood pressure.

A recent study at Edinburgh University examined the effects of UV rays on blood pressure in 34 volunteers. Participants were exposed to UV and heat lamps in one session and only heat in another.

Study Findings on UV Exposure and Blood Pressure

The study found that blood pressure significantly dropped after one hour of UV exposure but remained unchanged in the heat-only sessions.

Interestingly, the volunteers' vitamin D levels remained unaffected in both conditions. These results highlight the potential benefits of UV exposure on blood pressure regulation.

Related Reading

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• Can You Get Vitamin D from the Sun After 4 PM?

Download Our App to Track your Daily Sunlight Exposure Today

SunSeek helps you optimize your daily sunlight exposure by tracking and providing personalized recommendations based on your location, skin type, and health goals. The app combines real-time UV monitoring with guided outdoor activities to help you improve sleep, boost energy levels, and maintain optimal vitamin D levels throughout the year.

By aligning your daily routine with natural light cycles, SunSeek makes harnessing sunlight's health benefits easy while ensuring safe exposure through personalized timing recommendations and cloud coverage forecasts.

Download our app now to track your daily sunlight exposure.

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