Sunlight exposure does not just result in vitamin D production in our skin. It can also directly influence sleep quality through its effects on our circadian rhythms.[1] Increased exposure to sunlight in elderly nursing home residents can improve sleep quality scores.[2] Similarly, workers in windowless offices suffered from poorer sleep quality than those working by windows.[3] For workers in Antarctica in the winter,[4] the benefits of light can be produced using bright sun lamps, which make up for the negative effects of under-exposure of sunlight on sleep.[5] So, it seems that increased sun exposure could benefit sleep quality both through improved circadian rhythms and also increased vitamin D levels. Therefore, sun exposure is a confounding factor when studying the relationship between vitamin D levels and sleep.
How does sun exposure influence sleep?
Written by:
Fact-checked
by:
•Last Updated: May 16, 2025
Sun exposure positively influences sleep quality by affecting circadian rhythms and increasing vitamin D levels. Studies show that increased sunlight exposure can improve sleep quality in various populations, including nursing home residents (older adults) and workers in windowless offices.