Vitamin D could reduce risk of certain cancers

January 27, 2010 Results of the largest study ever conducted on the topic found people with the highest levels of vitamin D in their blood had a nearly 40 percent reduced risk of developing colorectal cancer. That's compared to those with the lowest level.

The findings of what's called the "epic" study confirm previous findings from smaller studies. Experts say, now, they have to figure out the right amount because of the potential side effects that can occur with too much vitamin D.