You’re likely aware that sunlight is the catalyst for Vitamin D production in our bodies. Specifically, UVB radiation from the sun activates the precursor of Vitamin D through our skin. It converts this precursor into usable Vitamin D in our body.33 Vitamin D then goes on to regulate our immune system,34–36 support the growth and repair of neurons,37–38 and assist in the production of neurotransmitters in our brains – including serotonin.39–40 Seeing that 80% of our Vitamin D stores come from sun exposure, sunlight is Vitamin D’s wingman.41
Outside of the effects on Vitamin D, sunlight sends some important signals to the body and brain. Exposure to the sun’s rays triggers the release of nitric oxide, which then supports the heart, lungs, and blood vessels.42 That’s also really helpful for our mental wellness, as adequate oxygenation is critical for brain function.
In addition, sunlight is a powerful regulator of our daily rhythms. These rhythms follow the sun’s path through the day.43–44 Our circadian rhythm is an internal biological clock that orchestrates all the chemical activity swishing around in our brain and body throughout the day. The sun is the reason why we are up and alert during the day, and become tired and sleepy at night.
Our circadian rhythm takes its cues from the various wavelengths of sunlight that beam down on us throughout the day. Bright, blue-wavelength light during the midday triggers us to to move our bodies and release energy. The red hue of sunset preferentially converts serotonin to melatonin to help orchestrate the onset of sleep.45 The absence of sunlight, or in other words darkness, allows our bodies to fall deeper into sleep and engage in restorative processes.46
Most important in all this is the morning sunlight exposure. That early morning light exposure anchors our circadian rhythm. Every day, morning light from the sun resets our clock, helping us to naturally stay awake and moving during the day and asleep and still at night. Greater light exposure during the morning and midday preps us to respond better to darkness as a cue for falling asleep.47 Following a daily activity pattern that is aligned with the sun’s rise, peak, and setting is really important to many biological rhythms inside your body and brain.
Sources cited in this section
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From The Mental Wellness Diet: Ancient Wisdom - Evolving Science - Modern Day Options © 2020 Justin Bethoney NP IPN, Inc.. Published for educational and informational purposes only; it is not a diagnosis, treatment or substitute for professional healthcare. Talk with your own clinician about your health.
