UV Health Privacy Policy

Effective Date: July 1, 2026
Last Updated: July 1, 2026

UV Health ("the App", "we", "us") is developed by Tingwei Zhang MD. We respect and protect your privacy. This policy explains what information the App collects, how it's used, and your rights.

1. Information We Collect

1.1 Information You Provide (Stored Locally on Your Device Only)

To calculate personalized sun-exposure recommendations, the App saves the following information only on your device (using iOS/Android local storage, AsyncStorage):

• Fitzpatrick skin type — to estimate your erythema threshold
• Body surface area (BSA) and clothing exposure — to estimate vitamin D synthesis
• Scalp exposure level — for Solar Window Hypothesis calculations
• Photosensitive medication status — for safety alerts
• Daily vitamin D target (IU) — for timer goals
• Notification and language preferences
• Timer session data (start time, elapsed time) — for session recovery

Important: All of this data is stored only on your device. It is never uploaded to our servers and is never shared with any third party. Uninstalling the App permanently deletes all of this data.

1.2 Information Automatically Collected (for Real-Time UV Lookup)

• Location (latitude/longitude or city): used to query the real-time UV index for your area. With each query, only coordinates are sent to our backend (Vercel) and our UV data provider (OpenUV.io). We do not store your location history.

1.3 Information We Do NOT Collect

• ❌ We do not collect names, emails, phone numbers, accounts, or passwords
• ❌ We do not collect device identifiers or advertising IDs
• ❌ We do not use third-party analytics (Google Analytics, Firebase, etc.)
• ❌ We do not show advertisements or share data with advertisers
• ❌ We do not track your activity across other apps or websites

2. Apple HealthKit (If You Enable It)

If you grant the App access to Apple Health, the App will write estimated vitamin D synthesis (in IU) into your iPhone's Health app under "Dietary Vitamin D."

• The App only writes vitamin D data — it does not read any other health information from you
• Health data stays on your iPhone, protected by Apple's encryption
• You can revoke access anytime in Settings → Health → Data Access
• Our servers never see your health data

3. Third-Party Services

The App uses the following third-party services for core functionality:

We encourage you to review these services' privacy policies.

4. Data Security

• All personal data on your device is protected by iOS/Android system-level security
• All communication with our backend uses HTTPS encryption
• We do not retain location queries — coordinates are discarded immediately after each lookup

5. Your Rights

• Access & Delete: You can view and modify all local data at any time on the "My Conditions" page. Uninstalling the App permanently deletes all local data.
• Revoke Permissions: You can disable location, notification, or HealthKit access anytime in your device settings.
• Contact Us: For any privacy concerns, email wuyang20200000@gmail.com

6. Children's Privacy

The App is not designed for children under 13. If a parent/guardian discovers that a child under 13 has used the App, they may contact us to request deletion of any related data.

7. Changes to This Policy

If we make material changes, we will notify you in the App and update the "Last Updated" date above.

8. Contact

For any questions about this Privacy Policy, contact:

Developer: Tingwei Zhang MD
Email: wuyang20200000@gmail.com