Are vitamin supplements good for health?

Almost every place that I go to, I see stores and stores just devoted to selling vitamins and more vitamins, and I was wondering what the benefits are of a normal healthy person taking vitamins daily. Are there any risks for a normal healthy person who doesn't take vitamins? Will the person taking vitamins' health be improved or have longer longevity? Will the person not taking any vitamins be as healthy as the person who is taking them? And also, what will happen if a person takes more than he or she should consume every day?


Can clothes protect my skin from the sun?

As the summer is soon to arrive, I was wondering what type of clothing should I wear to protect myself from the sun? Also, what color works best, light or black? I seem to be getting conflicting answers on the Internet. I am a fair skinned male. Thanks for your help!


Why do my bowel movements change when I get my period?

1) I've suffered weird digestive things when I have my period. The way I have heard it explained in my MCAT class is that the same hormone that causes the smooth muscle of the uterus to contract unfortunately works on all of our digestive organs as well, particularly the large intestine. So that's how I've come to grips with the apparent confusion of the digestive processes during my period.

2) Does a person's menstrual cycle regulate her bowels in any way? I have had some problems. The week before I get my period, I have loose bowels and the week afterwards I am quite constipated. Is this normal? Is there anything I can do?


Why do I feel unrested when I dream?

I go through phases where, when I sleep, I don't have any dreams (that I remember, at least). I sleep well and I wake up rested. Every few months I go through a week or two when I have nights full of incredibly vivid dreams and I wake up remembering at least five or six of them. Because of all these vivid dreams, I wake up feeling far less rested than I do when I don’t dream at all. Is there a particular reason for this? Does dreaming more at night mean your sleep is less restful?


Is it dangerous to not drink water during sport practice?

I have a question about dehydration. I am an eighteen-year-old female and play on a varsity basketball team. We usually have two-hour practices in which we work very hard. Our coach does not give us water breaks, and usually by the end of practice, we have cottonmouth and are "dying" for water. It is horrible. Is there any way that not having water during that time can be dangerous? Sometimes the team can feel sick or weak by the end of a practice.