Regular Non-Burning Sun Exposure is Normal, Beneficial: Researchers

A new commentary in the Journal of Investigative Dermatology highlights the benefits of regular, non-burning sun exposure—known as suberythemal UV exposure—as an essential part of human biology and adaptation.

“Sunlight exposure is normal for Homo sapiens,” write authors Jiayue Gu and Dr. Richard Weller of the University of Edinburgh, highlighting the following clinical implications:

Regular daily suberythemal UV exposure is normal for humans.
Suberythemal UV exposure has important health benefits.
Moderate irradiance with UV has beneficial immuno- logical effects.

The authors emphasize that most research has focused on the harms of irregular or excessive sun exposure, but studies like de Boer et al. (2025) show that “frequent suberythemal exposure to UV for mankind” allows the body “to adapt without inflammation to the local UV environment.” In fact, fair-skinned participants in the study developed a twofold increase in skin protection over just nine weeks of regular, non-burning UV exposure.

Beyond building tolerance, suberythemal sun helps regulate the immune system, they write. UV triggers natural cytokine responses in the skin, reduces inflammation, and modulates both innate and adaptive immunity. As Gu and Weller explain, “The time has come for dermatologists to stop only considering harms of sunlight exposure and treat it as just another environmental exposure, for which evolution has equipped us, and which has benefits as well as hazards.”

The commentary points to a growing body of evidence that realistic, everyday sun exposure supports more than vitamin D. From cardiovascular health to childhood eye development, sunlight’s benefits extend across multiple systems.

Click here to access the full commentary.

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