A new study of patients at the University of Kansas finds that giving vitamin D supplements to those with low blood levels of D cut their risk of dying from any cause in half.
Doctors also found, those low in vitamin D were more than twice as likely to have diabetes, 40 percent more likely to have high blood pressure, and about 30 percent more likely to have diseased heart muscle.
Still, the study doesn't prove that a lack of vitamin D causes those problems.
But -- for now -- the Institute of Medicine says, take 600 IU vitamin D supplements each day if you're under age 70, and 800 if you're older.
