Vitamin D

You know that expression about something being worth more than its weight in gold?

Well, there's a substance in the body so important that one tenth of a millionth of a gram (bear in mind that a gram is about the weight of one raisin) circulating in the bloodstream can make the difference between vibrant health and increased risk for heart disease, cancer, Parkinson's disease, osteoporosis, depression and other debilitating conditions.

How much is that worth? Medical writer Barbara Wexler explains why vitamin D is an important dietary building block by describing how it promotes good health and prevents disease, how much of it you need and where to get it.