actually, i can vouche for being on vitamins that you get sick much less. During high school, when i was in tip top shape, i took this mix of vitamins that you put into orange juice. It pretty much had your daily value of things you acually don't always get from everything you eat. During the 4 years of high school, i was probably had the flu and cold less than 3 or so times. my immune system was undestructable. That summer, i got lazy and stopped taking the vitamins and had a cold every other week.
vitamins = healthier immune system
at least thats the case with me.