Sit or stand in the sun for 20 minutes while you go through your morning routine, eating breakfast, checking the news, or exercising. You can go outside, sit by a window, or use a bright lamp, light box, red light, or LED light if the sun isn't out or is hard to get to. "It's important to get your vitamin D and also some exposure to sunlight to regulate your circadian rhythm and boost mood," Dr. Ho said. "Even 20 minutes of indirect sunlight through a window is helpful."