With the recent news of vitamin D pills not being useful in helping to fight a cold, experts are reminding people that the same holds true for vitamin C. Taking more vitamin C will not help you prevent a cold. It might, however, shorten the duration of cold if you already have one. 

A 2005 study published in PLoS ONE reported, after analyzing 30 years of scientific data available on the subject, that vitamin C intake doesn't prevent cold. The studies had a total of more than 10,000 participants.

Researchers in the study found that people who were taking about a gram of vitamin C had the same number of cold attacks as people who weren't taking such megadoses of the vitamin. According to Medline Plus, vitamin C may be helpful in preventing a cold if you live in a cold environment or are involved in extreme physical activities like marathon running.

While vitamin C won't help you fight your cold, it still offers plenty of health benefits. Vitamin C helps the body heal wounds, repair cartilage, bones and teeth. The vitamin isn't produced in the body nor stored, so people must get a continuous supply of the vitamin through diet. Citrus fruits like oranges and grapefruit have high amounts of vitamin C. But broccoli, green and red peppers, spinach, cabbage, sweet and white potatoes also have good amounts of the vitamin.

People who have kidney disease should avoid taking vitamin C supplements, says Medline Plus. Experts say that people should try and get the required amount of the vitamin from diets instead of getting it from pills. Excess amount of vitamin C is often lost through urine.