Explain what it means for the Physicians’ Health Study II to be….
a. …randomized.
b. …double-blind.
c. …placebo-controlled.

The Physicians’ Health Study II was a randomized, double-blind, placebo- controlled … trial of … vitamin C that began in 1997 and continued until its scheduled completion on August 31, 2007. There were 14,641 US male physicians enrolled, who were initially aged 50 years or older.