Vitamin D may have a role to play in preventing colds and flu, a study shows.

A new study adds to mounting evidence that vitamin C may have been stealing the spotlight all these years from the real cold fighter, vitamin D.

The study, the largest to date on the link between vitamin D and common respiratory infections, shows that people with the lowest vitamin D levels report having significantly more cases of cold and flu than those with higher levels.

Read the original article.

People who sleep less than seven hours a night are three times as likely to catch a cold.

A new study supports the theory that sleep is important to immune function. Volunteers who spent less time in bed were much more likely to catch a cold when viruses were dripped into their noses. People who slept longer and more soundly resisted infection better.

Read the article on Mercola.com's blog.