Effects of ultraviolet light exposure on blood pressure: a systematic review.

Abstract

Background: Hypertension is the leading global risk factor for cardiovascular disease. Ultraviolet (UV) radiation exposure has been proposed as a potential modifiable environmental factor influencing blood pressure regulation. While traditionally associated with vitamin D synthesis, emerging evidence suggests alternative mechanisms, including nitric oxide (NO) mobilization, may play a significant role.

Objective: To systematically review the available evidence on effects of UV exposure on blood pressure, with a focus on hypertension in human populations.

Methods: A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic databases were searched for studies investigating the impact of UV exposure (UVA and/or UVB) on blood pressure. Eligible studies included randomized controlled trials (RCTs), clinical trials, and observational studies involving human participants. Data extraction and risk of bias assessment were performed independently.

Results: A total of 14 studies were included in the final analysis. The majority demonstrated that UV exposure, particularly UVA, was associated with a reduction in blood pressure. Several studies suggested that this effect is mediated through NO release from cutaneous stores, independent of vitamin D pathways. However, findings were heterogeneous, with studies reporting no significant effects, likely due to differences in study design, population characteristics, and exposure protocols.

Conclusions: UV exposure, especially UVA, demonstrates a blood pressure-lowering effect, potentially mediated by NO-related mechanisms. However, clinical translation requires a balanced quantitative risk-benefit assessment that considers potential cardiovascular benefits, all-cause mortality-related evidence, and dermatological risks. Further large-scale and well-designed RCTs with standardized exposure protocols and long-term safety follow-up are required before UV-based interventions can be recommended for cardiovascular prevention or hypertension management.