So, except in special cases, some sun is good for most people. Over exposure can lead to bad sun burns and, in the worst case, melanomas (skin cancer).
Overall, too much time in the sun is bad because you get first degree burn
I got these source from these websites:
Link - http://uk.answers.yahoo.com/question/index?qid=20081124010436AAYzRa2
Link - http://answers.yahoo.com/question/index?qid=20080127134701AAsi43p
We should spend time in the sun
We must spend time in the sun, Sometime in the sun is healthy for us. Our body makes its own Vitamin D when we get out in the sun. It also makes Melatonin, which helps us sleep at night. As we age, our bodies make less Melatonin, but taking a walk in the sunlight can help to replete the supply and help an older person sleep better at night. Sunlight also helps in preventing and treating depression. People in cloudier climates have higher rates of depression than those in sunnier environments.
We should at least spend 20 minutes in the sun in the early morning, at least 3 times a day to absorb enough adequate necessary amount of ultraviolet rays producing vitamin D. Dr. Raymond Johnson of the Tulane School of Medicine exposed people to ultraviolet light. In 90 percent of the test subjects, their cardiac output increased an average of 39 percent. In other words, their hearts became stronger and pumped more blood.