Why were participants allowed to take their own personal calcium supplements?
The National Academy of Sciences currently recommends 1200 mg of calcium for adults more than 50 years old in order to maintain good health, but even doses much higher than that are considered safe. Although most people rely on getting enough calcium in their diet, some also take calcium supplements to meet this requirement. The WHI scientists wanted to make sure that participants continued these health habits as before, regardless of their CaD Trial study tablet assignment. During the CaD Trial, data on calcium intake was collected, so that a participants personal use of calcium supplements could be taken into account.
