Did you know?

1 billion people don’t get enough vitamin D.

It’s the world’s most common nutrient deficiency — and most people have no idea they’re affected.

Download Free on iPhone
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SunVitD app showing real-time UV index and vitamin D synthesis data
1 Billion+
People globally are vitamin D deficient
~50%
Of adults have insufficient levels
10+
Health risks linked to deficiency

What SunVitD Does

Everything you need to make the most of the sun

☀️

Live UV Index

Real-time UV data for your exact location. Know whether right now is worth stepping outside.

🧬

Personal Synthesis

Your vitamin D production rate in IU/min — calculated from your skin type, age, and body exposure.

📅

7-Day UV Forecast

Plan your week around the sun. See peak UV windows and best exposure days ahead.

🌬️

Air Quality Overlay

AQI data layered with UV so you know when the air is clean enough for outdoor exposure.

⏱️

Burn Time Guide

Know exactly how long you can safely stay in the sun — specific to your skin type and conditions.

🔒

Privacy First

No tracking, no ads. Sign in with Apple is optional. Your health data stays on your device.

How It Works

Your daily sun intelligence

Home

Everything at a glance

Open SunVitD to instantly see today's UV index, your personalised vitamin D rate, and the best exposure window.

  • Live UV index with hourly chart
  • Combined UV, Vitamin D, and AQI view
  • Best window times calculated for you
  • Burn guide in minutes for your skin
SunVitD home screen
Profile

Built around your body

Set your skin type, age, and how much skin you're exposing. Every estimate is yours, not a population average.

  • 6 Fitzpatrick skin types supported
  • Age-adjusted synthesis efficiency
  • Body exposure customisation
  • Instant IU/min recalculation
SunVitD profile screen
Forecast

Plan your week around the sun

See a full 7-day UV forecast with daily max values, sunrise and sunset times, and hourly breakdowns.

  • 7-day UV forecast with daily peaks
  • Hourly UV, Vitamin D, and AQI curves
  • Sunrise and sunset for any location
  • Best synthesis window per day
SunVitD forecast screen
✦ SunVitD Pro

Go deeper with Pro

Unlock advanced forecasting tools, combined hourly charts, and seven-day planning views.

  • Advanced UV + Vit D + AQI charts
  • Combined hourly forecast views
  • 7-day planning tools
  • Full forecast history
  • Priority data refresh
  • No ads, ever
Get SunVitD Pro
SunVitD Pro forecast detail

Common Questions

Frequently asked questions

Vitamin D deficiency means your blood levels of 25(OH)D are below 20 ng/mL. It affects over 1 billion people worldwide and is linked to weakened bones, impaired immunity, fatigue, and increased risk of chronic disease. Most people don’t realize they’re deficient because symptoms build gradually.
SunVitD uses real-time UV index data combined with your Fitzpatrick skin type, age, body surface area exposed, and solar zenith angle to estimate IU/min of vitamin D3 your skin produces. The model is grounded in peer-reviewed photobiology research.
Yes — core features including live UV index, personal synthesis rate, and burn time guide are completely free. No account required. SunVitD Pro unlocks 7-day forecasts, combined charts, and advanced planning tools.
No. SunVitD does not track you, serve ads, or share data with anyone. Sign in with Apple is optional and used only for account management. Your health data stays on your device.
No. SunVitD provides educational estimates based on scientific models. It is not medical advice. If you suspect vitamin D deficiency, consult a healthcare provider for blood testing and personalized guidance.

Start getting the vitamin D you need.

Free to download. Works anywhere in the world. No account needed.

Download Free on iPhone