UVHealthApp

Backed by published dermatology research. See today's UV, get a personalized vitamin D sun-time, and get warned when winter sun is too weak for high latitudes.

UV Health turns real-time UV data into a personal, easy-to-read reference for sun exposure — designed for people living at high latitudes, older adults, and anyone managing bone health.

Key features:

• Real-time UV Index for your location, with a plain-language risk label
• A personal reference for sun-exposure time based on your Fitzpatrick skin type and how much skin is exposed
• A redness (erythema) countdown so you know when to seek shade or reapply sunscreen
• A winter low-UV warning for high-latitude regions, where vitamin D synthesis nearly stops for months
• An optional module for AGA (male pattern) scalp exposure, based on the author's published Solar Window Hypothesis
• Full-day UV forecast curve to help you plan outdoor time
• Bilingual interface (English / Simplified Chinese), with a design built for larger text and easy tapping

UV Health is built on the Solar Window Hypothesis, published by dermatologist Tingwei Zhang, MD, in Medical Hypotheses (2026): a bald AGA scalp faces the sun directly and without hair coverage, which may make it a more efficient site for vitamin D synthesis — relevant for people with reduced VDR efficiency who are working to maintain bone density.

UV Health gives you reference information, not a medical diagnosis or treatment plan. All numbers are estimates based on modeled UV data, not a measurement on your skin. The app never suggests tanning or deliberately maximizing sun exposure — its purpose is sunburn prevention and a clearer, more personal picture of your vitamin D sun-time. Always talk to your doctor about your vitamin D levels, bone health, or any skin condition.

UV Health is free to use. Safety features (redness countdown, sunburn warning, disclaimers, and feedback) will always remain free.

Have feedback? We read every message — use the in-app feedback link any time.