Public health campaigns advise minimising solar UV radiation (UVR) exposure to prevent skin cancer. However, solar exposure also has health benefits, especially vitamin D synthesis. Thus, effective balancing of risks and benefits of solar UVR would be ideal if personalised recommendations were supported by accurate real-time solar dosimetry.
An innovative CE-marked medical app (Sun4Health®) has been recently developed for this purpose. The app performs real-time whole-body monitoring of both erythemal and vitamin D-effective solar UVR doses using patented technology that combines satellite data and AI-enabled automatic indoor/outdoor positioning [1,2], also incorporating the spectral transmittance and application quantity of the sunscreen applied. This enables personalised recommendations on optimal sun exposure time and sunscreen use with body-site specific recommendations. The app has been evaluated in two clinical studies.
First, a field study in Brazil, was performed to evaluate the app in a beach scenario with high UV index (UVI) [3]. 59 healthy volunteers were randomised into 3 groups, each given a different app providing: (1) UVI only (control), (2) personalised recommendations (Sun4Health®), (3) as (2) but with an additional wearable device that provides body site information (Sun4Health®-3D). Participants were offered sunscreens to use at their discretion. The results show that the app is safe and can modify behaviour to reduce erythema (28% less than control, 33% with 3D version), yet not decreasing vitamin D status.
Secondly, a randomised trial (n=100) in the UK has evaluated the efficacy of the app in real-world everyday conditions [4]. Preliminary results show good efficacy in supporting safe sunlight exposure to achieve personal daily recommended vitamin D synthesis (assuming oral equivalent of 400 IU/day as target).
Overall, clinical studies demonstrate that the app is safe to use and can effectively provide personalised real-time support to users for balancing risks and benefits of solar exposure.