On a day when I receive virtually no sun, I will always take 10,000 IUs. If I get some sun exposure, I will usually reduce my intake to 5,000 IUs or less. However, I was always unsure of how much to reduce my supplementation on days when I received significant sun exposure.
Someone on HealClick recently posted about an app that helps with that. It factors your location, time of day, time exposed to sun, percentage of skin exposed and some other parameters and calculates how many IU's of vitamin D you received.
Here's the description of the App by its creators:
"The idea behind this application is that it will help you track and manage your Vitamin D.
You setup basic information one time, like your height and weight and skin type and then any time you are outside, during the prescribed hours (and parts of the year), you can have it compute the amount of D you are getting in a stopwatch interface. It will also track how long you can stay out and warn you when the time is up.
The application will notify you with the next opportunity to generate vitamin D.Here is a link to the Apple version of the app. And here it is for Android.
Each day, you can see forecasts based on your location, and you can also see the solar position, [and] your generated vitamin D vs. target etc."
There's also an interesting little YouTube video about Vitamin D and sun exposure from the makers of the app. I learned a few things from it. It's worth a watch.
I've just downloaded the app so I haven't had a chance to use it yet. I'll come back and add a review after I've had a chance to 'take it for a spin...'