Systemic effects of sunlight: 10-year review of cardiovascular, infection and cancer outcomes.

Sunlight is an important environmental determinant of human physiology, though its effects on health have been studied predominantly in the context of skin disease. While ultraviolet (UV) radiation is a well-established risk factor for skin cancer, evidence suggests that it may also have beneficial systemic effects. This narrative review synthesizes evidence from the past decade on the associations between sunlight and UV radiation exposure and mortality-related outcomes, with a focus on internal malignancies, cardiovascular disease and infectious diseases. A comprehensive search of PubMed and Embase was conducted for English-language articles published between January 2015 and June 2025. Of 148 articles identified, two duplicates were removed. After title and abstract screening, 64 full-text articles were assessed for eligibility; a total of 28 studies met the inclusion criteria and were included in the final review. Among the included studies, four examined cardiovascular outcomes, 12 evaluated infectious diseases, six focused on malignancies and six assessed all-cause mortality. Overall, most studies reported inverse associations between UV exposure and adverse health outcomes, suggesting potential protective effects. For example, a large cohort study found that individuals with 2000 kJ/m