Now that we're all convinced sunlight is the equivalent of the modern day antichrist when it comes to the skin cancer prevention, we may have swung the pendulum too far. Less sunshine, less risk of skin cancer, yes, but too little sunshine and we have a greater risk of developing other types of cancers: breast and colon, for example. Autoimmune disorders may result from too little sunshine as well, such as multiple sclerosis and diabetes.
Sunlight and Vitamin D may play a role in depression as well. Seasonal Affect Disorder, or SAD, is believed to occur when people get too little sunshine. It is especially prevalent in places like Alaska and Seattle. I believe my own depression was related to getting too little sun. I belong to a gym and for years got my primary workouts indoors. A few years ago, however, I went back to playing tennis (after long hiatus). My indoor gym workouts were replaced by sunshine supplemented workouts. Very quickly I found myself feeling much better: more energy, better moods, improved sleep patterns. I may not be getting the same quality workout, but I feel better and that quickly became more important to ME and my everyday functioning.
SAD experts recommend 15-30 minutes of exposure to sunlight daily as a natural "antidepressant." Take a morning walk, sit outside and read the paper or take your work break outside. Make it a part of your daily routine, for sunshine's sake. For a more detailed look at SAD, read here.
The Harvard School of Public Health's Nutrition Department publishes The Nutrition Source, a website talking about various health and nutrition topics. If you want to read more on Vitamin D, here is a good place to start. Their overview of guidelines and good stuff found in multi-vitamins can be read here.
And one more healthful offering: Oprah's experts, Drs. Oz and Roizen, put together an antiaging checklist which includes the recommendation to take 1000 units of D daily to keep us looking and feeling young. Dr. Oz was mentioned in a comment by Jeanne of knitresolution blogfame, sharing that he recommends splitting multi-vitamins and taking half in the morning and half in the evening to get maximum benefits.