Higher ultraviolet light exposure is associated with lower mortality: An analysis of data from the UK biobank cohort study

The short version: the retrieved evidence does not directly test whether higher UV exposure predicts lower all-cause mortality in a UK Biobank cohort, so the question remains open.

The evidence you have is a collection of studies on related but different questions. Several show that sunlight matters for vitamin D status in the elderly [19], that vitamin D deficiency tracks with hip fracture [18] and Parkinson's risk [9], and that countries with more solar radiation have lower Alzheimer's death rates [15]. One retrospective study from 1980 linked higher solar radiation with lower colon cancer mortality in U.S. states [14]. A 6-month intervention in Saudi adults showed that a lifestyle program including more sun exposure raised vitamin D and improved cholesterol and triglycerides [16]. But these are a mix of ecological correlations and small intervention studies, none of them a cohort study that isolates UV exposure and measures all-cause death in a UK general population.

The study that would answer the question — a prospective cohort within UK Biobank with measured or modeled UV exposure, confounder adjustment, and all-cause mortality as the endpoint — is not in this retrieval. The closest is the Parkinson's case-control [9], but that was in China and used disease risk, not death. The Alzheimer's country-level comparison [15] is ecological and cannot control for individual confounders. The most informative study design was not retrieved. Observational studies consistently find that people who spend more time outdoors have lower all-cause mortality, but that is contaminated by physical activity, socioeconomic status, and baseline health. The effect of UV itself, independent of those factors, is not settled by these records.

My call: the evidence here does not establish whether higher UV exposure predicts lower all-cause mortality in a UK Biobank cohort, because no such study appears in the retrieval. The broader literature outside this retrieval is observational and confounded, with no consensus. Confidence: low for a causal claim either way, based on this retrieval.