Sunlight and Your Health: The Essential Rays of Life

Sunlight and Your Health: There’s something about the warmth of the sun on your skin that is hard to resist. While we need to be conscious of how much sun we get, sunshine plays a uniquely beneficial role in our well-being and overall health.

Sunshine is essential to help regulate the body clock known as circadian rhythms, affecting energy, sleep, body temperature, and much more. Learn more about why sunshine matters for your health and what you can do to stay well when the days get long and dark.

This article has been medically reviewed by Dr. Charles Penick, MD

How does sunlight help our health?

Sunlight and Your Health: Daily sunshine contributes to our mental and physical wellness and is even associated with a higher quality of life. If you’ve ever spent time in the sun, even just sitting for a few minutes to get fresh air, you may have experienced this feeling.

The health benefits of sunlight are well-documented. Even prisoners in solitary confinement are allowed time outside because the alternative is so bad for psycho-social and physical well being.

Some of the ways that sunshine improves our health include:

• Supports sleep. Sunshine impacts your sleep habits through hormone production and circadian rhythms. The more sunshine you are exposed to during the day, the better your body can produce melatonin, a hormone essential for sleep. Melatonin drops during the day and rises at night in response to darkness. Exposure to early morning sunlight helps to produce more melatonin at night.

Similarly, your circadian rhythm dictates the body’s natural sleep and wake patterns, impacts the release of hormones like melatonin, and even can play a role in gut bacteria’s behavior. Humans have photoreceptors in the retina of our eyes that help mediate the impact of light on the body’s natural rhythms. Too much artificial light or not enough natural sunlight can throw off these rhythms, leading to insomnia and sleep disorders.

Making sure you get morning light on your skin and in your eyes, first thing in the morning helps wake you up to energize for the day and help you fall asleep at night.

• Improves mood. The connection between mood disorders and sunshine is well documented. Specifically, sunlight can help to increase levels of serotonin in the brain. Serotonin, a feel-good neurotransmitter, is deeply connected to mood disorders, so much so that many antidepressants target it for treatment. It also helps you feel calm and plays a role in sleep and digestion.

Lack of sunlight is also associated with Seasonal affective disorder (SAD). SAD is a type of depression that occurs during the winter months when less sunshine is less available. It typically lasts during the colder months and improves when the seasons shift, but the symptoms are very similar to major depression. SAD is also associated with reductions in serotonin levels.

Add these physiological reasons to more practical reasons that also impact mood. People are more likely to go outside and move their bodies in nice weather than cold wintery months. Exercise is a known mood enhancer that gives us natural mood boosters known as endorphins. Movement also is well documented for its positive role in stress management. This means that less sunshine gives a double edge sword – decreased serotonin and less motivation to participate in activities that we know are natural therapies for mood enhancement.

• Vitamin D production. Perhaps one of the most commonly known benefits of sunshine is that it makes vitamin D. Vitamin D is a hormone essential for immune health, bone health and even plays a role in decreasing cancer risk. Vitamin D is unusual because there aren’t many foods that provide enough to be considered a rich source (oily fish, fortified eggs, and milk), but the body can make it through the interaction with the sun.

When our skin is exposed to ultraviolet B rays from the sun, receptors in the skin can make active vitamin D (25-hydroxyvitamin D) in the liver and kidneys.

In the past, vitamin D’s benefits were relegated to only bone health because it helps shuttle calcium to the bones. While it is essential for bone health, in recent years, vitamin D research has shown us the important role it plays in so many other functions. We now understand that vitamin D is critical for:

• Immune health because it can help activate the immune system and may even play a role in the expression of genes associated with our immune system.

• Mental health. In the same way that lack of sunshine can contribute to alterations in mental health from reductions in serotonin, it can also contribute to low vitamin D, which in turn is associated with depression. Studies show that while it may not help you if your levels are already optimal, people with low levels of vitamin D who are depressed may see improvement with vitamin D supplementation. Low vitamin D status is also associated with SAD.

Sunlight and Your Health: How to support your health when sunshine is lacking

So what can you do if it’s the deep of winter and you aren’t lucky enough to live in a tropical environment? There are several natural steps you can take to take care of yourself when you don’t have access to sunlight:

• Supplements. The easiest way to start combating the winter health blues is to supplement with vitamin D. Studies have found estimates of 24-40% of people are deficient in vitamin D. Even if you do live somewhere with more sunshine, many people use sunscreen or wear protective clothing in the peak sun hours which interferes with vitamin D production.

Vitamin D supplements are an easy way to make sure you have adequate levels. Ideally, you should obtain a current vitamin D level to assess your baseline so you can take the appropriate dose. Keep in mind that a vitamin D supplement that includes vitamin K is essential, especially for bone and cardiovascular health. And as vitamin D is a fat-soluble vitamin, you will want to make sure you take it with a meal for optimal absorption.

• Light therapy. Light therapy is a simple yet effective intervention for mood disorders associated with low sunshine, especially SAD. Studies have shown that just twenty to thirty minutes a day are beneficial when used regularly. Of course, you should always check in with a healthcare provider if you are concerned with any changes related to your mood.

• Get outside. While not possible for everyone, getting outside for even twenty minutes can help enhance mood, support vitamin D production, and support stress relief. Get out for a walk and move your body. And as the winter months pass, try to get outdoors first thing after waking up (or even stand in front of a big window) to get early morning sunlight to set your circadian rhythms for the day.

Sunlight and Your Health: Summing up the need for sunlight

Sunshine is essential for your well-being and health. It enhances hormone production to support sleep and wake cycles, impacts mental health, and is needed to produce vitamin D.

When you have less access to sunshine in the winter months, make sure you check vitamin D levels and supplement as needed, get outside when you can, and consider light therapy as a natural approach for SAD.

Medical Disclaimer: This article is based upon the opinions of Dr. Daniel Pompa. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from the research and experience of Dr. Pompa and his associates. This article has been medically reviewed by Dr. Charles Penick, MD for accuracy of the information provided, but Dr. Pompa encourages you to make your own health care decisions based upon your research and in partnership with a qualified health care professional.

References:

1. Smolensky, Michael H., Linda L. Sackett-Lundeen, and Francesco Portaluppi. “Nocturnal Light Pollution and
   Underexposure to Daytime Sunlight: Complementary Mechanisms of Circadian Disruption and Related Diseases.”
   Chronobiology International 32, no. 8 (2015): 1029–48. https://doi.org/10.3109/07420528.2015.1072002.
2. Aries, MBC, MPJ Aarts, and J van Hoof. “Daylight and Health: A Review of the Evidence and Consequences for the Built
   Environment.” Lighting Research & Technology 47, no. 1 (February 1, 2015): 6–27.
   https://doi.org/10.1177/1477153513509258.
3. 3 https://www.apa.org. “How Long Can Inmates Legally Be Deprived of Outdoor Activity?” Accessed January 7, 2021.
   https://www.apa.org/monitor/2018/12/jn.
4. Masters, Alina, Seithikurippu R Pandi-Perumal, Azizi Seixas, Jean-Louis Girardin, and Samy I. McFarlane. “Melatonin, the Hormone of Darkness: From Sleep Promotion to Ebola Treatment.” Brain Disorders & Therapy 4, no. 1 (2014).
   https://doi.org/10.4172/2168-975X.1000151.
5. Mead, M. Nathaniel. “Benefits of Sunlight: A Bright Spot for Human Health.” Environmental Health Perspectives 116,
   no. 4 (April 2008): A160–67.
6. “Circadian Rhythms.” Accessed January 7, 2021. https://www.nigms.nih.gov/education/fact-sheets/Pages/circadian-
   rhythms.aspx.
7. Blume, Christine, Corrado Garbazza, and Manuel Spitschan. “Effects of Light on Human Circadian Rhythms, Sleep and
   Mood.” Somnologie 23, no. 3 (2019): 147–56. https://doi.org/10.1007/s11818-019-00215-x.
8. Sansone, Randy A., and Lori A. Sansone. “Sunshine, Serotonin, and Skin: A Partial Explanation for Seasonal Patterns in
   Psychopathology?” Innovations in Clinical Neuroscience 10, no. 7–8 (2013): 20–24.
9. “NIMH » Seasonal Affective Disorder.” Accessed January 7, 2021.
   https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder/index.shtml.
10. “Office of Dietary Supplements – Vitamin D.” Accessed January 7, 2021. https://ods.od.nih.gov/factsheets/VitaminD-
    HealthProfessional/.
11. Nair, Rathish, and Arun Maseeh. “Vitamin D: The ‘Sunshine’ Vitamin.” Journal of Pharmacology &
    Pharmacotherapeutics 3, no. 2 (2012): 118–26. https://doi.org/10.4103/0976-500X.95506.
12.  “Vitamin D Controls T Cell Antigen Receptor Signaling and Activation of Human T Cells | Nature Immunology.”
    Accessed January 7, 2021. https://www.nature.com/articles/ni.1851.
13.  Shirvani, Arash, Tyler Arek Kalajian, Anjeli Song, and Michael F. Holick. “Disassociation of Vitamin D’s Calcemic Activity
    and Non-Calcemic Genomic Activity and Individual Responsiveness: A Randomized Controlled Double-Blind Clinical
    Trial.” Scientific Reports 9 (November 27, 2019). https://doi.org/10.1038/s41598-019-53864-1.
14. Penckofer, Sue, Joanne Kouba, Mary Byrn, and Carol Estwing Ferrans. “Vitamin D and Depression: Where Is All the
    Sunshine?” Issues in Mental Health Nursing 31, no. 6 (June 2010): 385–93.
    https://doi.org/10.3109/01612840903437657.
15. 15 Amrein, Karin, Mario Scherkl, Magdalena Hoffmann, Stefan Neuwersch-Sommeregger, Markus Köstenberger, Adelina
    Tmava Berisha, Gennaro Martucci, Stefan Pilz, and Oliver Malle. “Vitamin D Deficiency 2.0: An Update on the
    Current Status Worldwide.” European Journal of Clinical Nutrition 74, no. 11 (November 2020): 1498–1513.
    https://doi.org/10.1038/s41430-020-0558-y.
16. Ballegooijen, Adriana J. van, Stefan Pilz, Andreas Tomaschitz, Martin R. Grübler, and Nicolas Verheyen. “The Synergistic
    Interplay between Vitamins D and K for Bone and Cardiovascular Health: A Narrative Review.” International
    Journal of Endocrinology 2017 (2017). https://doi.org/10.1155/2017/7454376.
17. Campbell, Philip D., Ann M. Miller, and Mary E. Woesner. “Bright Light Therapy: Seasonal Affective Disorder and
    Beyond.” The Einstein Journal of Biology and Medicine : EJBM 32 (2017): E13–25.