Vitamin D's Grade: A+, or Incomplete?

Vitamin D, the "sunshine vitamin," has been getting plenty of good press lately, leading some to ask why more people aren't guzzling it to help stave off heart disease, cancer, and diabetes. But as the government looks to update its guidelines, many experts warn that bombarding people with the vitamin could be dangerous as well, the Washington Post reports.

"The data are intriguing and serve as, no pun intended, food for further fruitful research," according to the National Institutes of Health, but "we have to be cautious." Government recommendations, which have remained static for a decade, focus mainly on preventing rickets and osteoporosis. But with possible benefits ranging from fighting depression to preventing the flu, a new recommended dose may be needed. (More Sunshine vitamin stories.)