Whether helping to boost your vitamin D or warding off the winter blues, there are several reasons to get your fill of sunshine each day.

If you are like many, you crave sunshine after a long, cold, and gloomy season of winter. Aside from providing wonderful warmth to your skin, spending time outdoors in the sun can boost your health in a variety of other ways. Read on to find out how, and learn what you can do to ensure you are doing it safely.

1. When your skin is exposed to sunlight, it manufactures vitamin D

Also known as the “sunshine vitamin,” vitamin D is critical for a number of bodily functions, including maintaining healthy bones and teeth, supporting the immune system, and regulating cell growth and blood pressure. To determine whether you have enough vitamin D in your blood, your healthcare provider can prescribe a simple blood test. Experts suggest that having a vitamin D level above 20 ng/mL in your blood is ideal, and there are three primary ways to get it. The first is to eat foods that are fortified with vitamin D, like milk, yogurt, and orange juice products, and foods such as egg yolks, salmon, and tuna that naturally contain it.

Many people also take vitamin D supplements to get their daily dose in. There are two types of vitamin D that are available in supplement form, vitamin D2 and vitamin D3. Both types of supplements are effective in raising vitamin D levels in the blood, but vitamin D3 is generally more effective. Adults aged 19 to 70 are recommended to take 600 IU of vitamin D per day, whereas adults aged 71 or above are recommended to take 800 IU per day.  This goal can be achieved through food alone or food plus a supplement. If a blood test shows that you are deficient in vitamin D, your healthcare provider may recommend that you take a higher dose.

A third way to get vitamin D naturally is by exposing the skin to the sun. When your bare skin is exposed to sunlight, it produces vitamin D. The sun’s ultraviolet B (UVB) rays interact with a protein called 7-Dehydrocholesterol (7-DHC) in the skin, converting it into vitamin D3, the active form of vitamin D. Most people can get some vitamin D by spending a few minutes in the sun each day, although the amount of sun exposure needed varies depending on factors such as the time of year, presence of clouds and smog, usage of sunscreen, latitude, skin pigmentation, and age.

2. Exposure to the sun can improve your quality of sleep

Many people struggle to get the recommended seven or more hours of sleep each night. Sleep disorders like insomnia are common and can be triggered by anxiety and stress, shift work, certain medications, and physical health conditions. Poor sleep can also be caused by a disruption in the body’s circadian rhythm.

Circadian rhythms are the physical, emotional, and behavioral changes that occur in the body over a 24-hour cycle. It impacts practically every physiological process in the body and brain, influencing how every cell, organ, and tissue works. The sleep-wake cycle is a great example of processes that rely on the body’s circadian rhythm. Darkness cues your brain that it’s time for sleep and to make more melatonin so that you feel drowsy, while morning sunlight notifies your brain that it is daytime, rousing you awake and keeping you alert.

Both internal and environmental factors play important roles in influencing the body’s circadian rhythms.  Daylight exposure is a key player when it comes to regulating the body’s circadian rhythms and sleep-wake schedule. The incoming daylight from the sun that you see stimulates the eye’s optic nerves, directing the body’s central circadian rhythm.

As one 2021 study found, spending more time outside during the daytime may significantly improve sleep. During the study, more than 502,000 adult UK residents provided detailed information about their lifestyle and health habits. The average time the group spent outdoors in the daylight was 2.5 hours each day, and it was discovered that spending more time outdoors made it 47% easier to get up in the morning, 19% less likely to feel tired frequently, and led to 4% fewer insomnia symptoms. More sunlight also resulted in a 24% increase in the likelihood of going to bed earlier.

3. Getting sun can improve your mood

It is no secret that quality of sleep can influence mood. Being well-rested helps us regulate our emotions, whereas poor sleep can lead to feelings of irritability, frustration, and difficulty concentrating. Sunlight’s critical role in regulating the body’s sleep-wake cycle - and in turn, leading to more quality sleep - goes hand in hand with a perked-up state of mind, and many of the previous study participants experienced this benefit firsthand.  Of the 502,000 subjects, 160,000 filled out an additional online questionnaire about their mental health, and it was found that for each additional hour they spent outdoors in the sunlight, they experienced not only a 45% higher rate of self-reported happiness but also a 4% less likelihood of having a major depressive disorder and 5% less likelihood of using antidepressant medications.

The influence sunlight can have on mood can especially be seen in the fall and winter months, when many people experience seasonal affective disorder (SAD), a condition characterized by feeling gloomy when the days are shorter and feeling better in the spring when daylight hours are longer. The exact cause of SAD is unknown, but some experts believe it may be triggered by the deprivation of sunlight and a shift in circadian rhythm during those colder months.

Many people find relief using bright light therapy which works to compensate for the loss in daylight. Researchers believe that light therapy may alleviate SAD symptoms by helping to reset the body’s circadian rhythm and suppressing the secretion of melatonin, a hormone that regulates sleep. This can help synchronize the circadian rhythm to a more favorable sleep-wake cycle, improving alertness and leading to better quality sleep. Current clinical guidelines recommend sitting in front of a bright light box with 10,000 lux intensity for 30 minutes every morning.  

Another perk of getting out in the sun? Being outdoors can cheer you up by allowing you to have fun being physically active and socializing with others, both of which have a positive impact on mood.

4. Sunlight may protect your heart

As the leading cause of premature death, heart disease remains a critical health concern around the world, with high blood pressure being a predominant risk factor. But it appears that being exposed to regular sunlight may benefit your heart in one significant way.

The skin contains nitrogen oxides which convert to nitric oxide when exposed to the sun’s ultraviolet radiation and are then transported throughout the blood. Nitric oxide helps to regulate blood pressure by relaxing and widening the blood vessels, which allows blood to flow more easily. While more research is needed, some experts suggest that the skin’s release of nitric oxide from sun exposure may have protective effects for the heart.

Staying safe in the sun

There are multiple ways spending time in the sun can benefit your health, but it is critical to do so safely. Too much ultraviolet radiation exposure can damage the skin, increasing the risk of skin cancer.

Follow these tips to protect your skin while spending time outside in the sun:

  1. The sun’s ultraviolet rays are strongest between 10 AM and 2 PM, so seek shade during this timeframe to minimize harmful exposure.
  2. Wear clothes that will protect your skin from ultraviolet rays, like long-sleeved shirts, pants, wide-brimmed hats, and sunglasses with UV protection.
  3. Apply sunscreen daily or anytime you are outside, even on cloudy days. Choose a sunscreen with an SPF of 30 or higher that is broad-spectrum, which means it protects against both UVA and UVB rays. Cover all areas of exposed skin, paying extra special attention to your ears, your neck, the tops of your feet, and the top of your head. Reapply every two hours after sweating or swimming.
  4. Avoid tanning beds, as their ultraviolet rays can also cause premature skin aging and skin cancer.
  5. If you notice any new or suspicious spots on your skin, consult a board-certified dermatologist.

The bottom line

Although sun exposure each day may help naturally boost your vitamin D, increase your chances of a better night’s sleep and a cheerful mood, and may even lead to a lowering of blood pressure, it is vital to spend time in the sun responsibly and safely to minimize your risk of skin cancer and skin damage. Make sure to apply sunscreen with a minimum SPF of 30 daily, even when cloudy, avoid the sun between 10 AM and 2 PM when the ultraviolet rays are most potent, and wear protective clothing whenever possible. While wearing sunscreen will likely reduce the amount of vitamin D your body can produce, most people do not wear enough sunscreen, or wear sunscreen consistently enough, to block out all ultraviolet rays. But if you believe you are at risk of low vitamin D, make sure to consult your healthcare provider. A vitamin D deficiency can cause loss of bone density and soft, weak, and painful bones, so if the vitamin D level in your blood is low (20 nmol/L1 or less), your provider can help guide you with taking a daily supplement to increase your level safely.


  1. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/
  2. https://link.springer.com/article/10.1007/s43630-021-00015-z
  3. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/
  4. https://www.cdc.gov/sleep/features/getting-enough-sleep.html
  5. https://www.cdc.gov/sleep/about_sleep/key_disorders.html
  6. https://www.nhlbi.nih.gov/health/circadian-rhythm-disorders
  7. https://www.ncbi.nlm.nih.gov/books/NBK519507/
  8. https://www.nhlbi.nih.gov/health/sleep/sleep-wake-cycle
  9. https://www.researchgate.net/publication/341211230_The_Impact_of_Optimized_Daylight_and_Views_on_the_Sleep_Duration_and_Cognitive_Performance_of_Office_Workers
  10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3860420/
  11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8892387/
  12. https://mental.jmir.org/2019/3/e12613
  13. https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder
  14. https://www.nhs.uk/mental-health/conditions/seasonal-affective-disorder-sad/overview/
  15. https://www.tandfonline.com/doi/full/10.31887/DCNS.2003.5.4/npraschakrieder?scroll=top&needAccess=true&role=tab
  16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6405415/
  17. https://journals.lww.com/acsm-csmr/fulltext/2019/08000/the_role_of_exercise_in_preventing_and_treating.6.aspx?mc_cid=784bd3822a&mc_eid=c293f3f217
  18. https://www.scirp.org/journal/paperinformation.aspx?paperid=91323
  19. https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death
  20. https://www.karger.com/Article/Pdf/441266
  21. https://www.karger.com/article/fulltext/338150
  22. https://www.karger.com/Article/Pdf/441266
  23. https://www.cancer.org/healthy/be-safe-in-sun.html
  24. https://www.aad.org/public/diseases/skin-cancer/prevent/how
  25. https://www.health.harvard.edu/staying-healthy/6-things-you-should-know-about-vitamin-d