2,400+ sun sessions tracked this weekLive forecasts for 50+ citiesMore than 4 in 10 adults are low on Vitamin D2,400+ sun sessions tracked this weekLive forecasts for 50+ citiesMore than 4 in 10 adults are low on Vitamin D
Touch grass, but make it science

Tired all the time, low mood, and no idea why?

Low Vitamin D could be part of it. Your body only makes Vitamin D when the sun is strong enough. Bask tells you when to step outside.

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Free·iPhone·No account needed
Great time for sun
20 min to Vitamin D goal
● Window · 1:22pm to 4:00pm
☁ Light clouds · UV reduced by 25%
Bask sun mascot
The problem

You eat well. You sleep enough. So why are you still dragging?

It might be low Vitamin D. Your body makes it from sunlight, but most of what you actually get doesn't count.

Sunny doesn't mean useful.

Vitamin D needs strong enough UVB (the sun rays that make Vitamin D) at the right sun angle. If the sun is low, it can be bright outside and still make little to none.

Sun through a window doesn't make Vitamin D.

Glass blocks the UVB your body needs for Vitamin D, so desk sunlight feels good but does not count toward production.

Winter sun barely works.

Depending on where you live, the sun can sit too low for months to help your body make much Vitamin D.

Bask sun mascot
Bask doesn't just track sunlight.
Bask makes sure your sun actually counts.
60-second check

Could low Vitamin D be why you feel this way?

You're not alone. More than 4 in 10 adults are running low. Answer three quick questions to see your Vitamin D risk score.

1. Where do you live?

How Bask works

The easiest way to make sunlight work for you.

01 · Best time

Know the best time to go outside.

Bask checks the weather and finds your window. "Head out around 1:00. Twenty minutes covers you today." No more wondering if it's even worth it.

9:41
Bask forecast showing today and tomorrow best sunlight windows
Bask sun mascot
02 · Sun that counts

Know if your sun actually counted.

Most apps just show you the weather. Bask tells you whether you really got what you needed, based on your skin, what you're wearing, and the clouds.

9:41
Bask home screen with daily IU progress ring
Bask sun mascot
03 · Live sessions

Track your time outside like a workout.

Tap start, put your phone away. Bask keeps time and gives you a heads-up before you've had too much.

9:41
Bask live session tracker with UV and burn risk
Bask sun mascot
What you get

What you get with Bask

One simple goal
Sun and any Vitamin D supplements both count toward the same daily target.
Plan ahead
See whether tomorrow looks like a good sun day, or whether logging supplements may make more sense.
Real-time sessions
Get a heads-up when it may be time to head back in.
Took a supplement? Log it
Bask adds it to your day automatically.
The helpers that matter
Track magnesium and K2, the two things that help your body actually use Vitamin D.
Works with Apple Health
Sync Vitamin D supplements and Time in Daylight with Apple Health.
See your progress
Streaks, weekly averages, and longer trends on Pro.
Never miss a good window
Pro nudges you before the best time each day.
Stays on your phone
No account, no cloud, and nothing's ever sold.
FAQ

Questions, answered.

Clear answers on sunlight, Vitamin D, privacy, and what Bask can and can't tell you. If you've got a question we missed, support@getbask.app.

Can I really get Vitamin D from the sun in winter?–
It depends on where you live. For a good chunk of the year in many places, the sun sits too low to make much Vitamin D. Bask shows you when it's actually working, and when you're better off taking a supplement.
Bask sun mascot

The easiest fix for feeling tired might be free.

It's sunlight, and most people just don't get it right. Bask helps you change that, starting today.

Download free for iOS
Free · iPhone · No account needed