Features
Everything you need to optimize your Vitamin D from the sun, stay safe, and track your levels over time.
Sun Tracker
Wherever you go in the world, dminder tracks the sun and tells you when you can get Vitamin D. It knows the exact times UVB enters the atmosphere at your location and shows you the optimal window for sun exposure. If D isn't available today, it tells you when your next opportunity will be.
Vitamin D Stopwatch
Set a target by amount of D or time before starting your exposure session. The timer counts up or down to your target, applying all the factors that determine how much D you can get: skin tone, age, weight, and amount of skin exposed. When you reach your goal, it alerts you so you can go inside or apply sunscreen.
MED-Based Safety
dminder calculates your personal Minimal Erythemal Dose (MED) — the UV threshold where your skin starts to redden. Using your Fitzpatrick skin type, real-time UV index, ozone data, and solar angle, it counts down to your MED limit with an 80% safety margin built in. Turn over to reset the countdown for the other side.
Mini-Player
Start a sun session, then keep using the app. Browse your history, check your progress, update your profile — your timer keeps running in a compact bar at the bottom of every screen. Tap to expand back to the full timer. Swipe the time display to toggle between elapsed and countdown.
Automatic Overcast Detection
Start a timer on a cloudy day and dminder reads real-time cloud data — including separate low, mid, and high altitude layers — then sets your overcast level automatically. Your vitamin D rate and MED time adjust instantly to actual sky conditions.
D Level Estimator
All your doses of D, from the sun or supplements, are used to continuously estimate your current blood level. Enter lab results to calibrate the model. The number one goal is to give you a tool to avoid falling into deficiency. Gauges show your estimated level and production over the last 30, 60, and 90 days.
Optimal Time of Day
dminder notifies you when solar noon is approaching — the best time to get Vitamin D because the sun is at its highest point and the UVA/UVB ratio is optimal. Going at the right time means less time in the sun for the same amount of D.
Forecaster
See the forecast for the next 5 days plus an annual solar forecast that shows exactly what days of the year Vitamin D will be available at your location. Plan ahead so you never miss a D opportunity.
Customizable Profile
The amount of pigment in your skin affects D production — the difference between lightest and darkest is 10x. dminder considers your Fitzpatrick skin type, age, weight, and how much skin you have exposed for accurate, personalized calculations.
Health App Integration
dminder integrates with Apple Health on iOS and Health Connect on Android. Your Vitamin D data flows into your health dashboard alongside everything else you track. Weight and other profile data can sync automatically.
Coaching & Progress
Smart notifications that know when to nudge you and when to leave you alone. Achievement badges that reward consistency. A progress dashboard that shows your sufficiency streak, badge collection, and IU production over time. Learn more →
Ready to optimize your Vitamin D?
