Vitamin D is important because it can kind of get you stuck in a loop. You don't leave the house because of depression and don't get Vitamin D because you don't leave the house and the deficiency greatly heightens the symptoms of depression.
I had debilitating depression and my doctor actually prescribed vitamin D and told me to get outside and do more exercise.
The first year was a slight improvement, the second year I forgot the vitamin D until late winter and the third year I really began to notice the difference.
It's been about 6 years now and the change has been drastic.
Did you forget the funny?