Calcium/Vitamin D Supplementation Study Fact Sheet
WHAT WAS THE PURPOSE OF THE CALCIUM/VITAMIN D (CAD)
Previous research on calcium/vitamin D and its effect on
bone fractures is limited. Past research in this area is observational and
focused more on bone mass than the frequency of bone fractures. Observational
studies also suggest that increased calcium and vitamin D intake may decrease
the risk of colorectal cancer.
The calcium/vitamin D study tested whether these
supplements reduce the risk of colorectal cancer and the frequency of hip and
other bone fractures in postmenopausal women.
HOW WAS THE CAD STUDY CONDUCTED?
Women in the hormone therapy and/or the dietary
modification clinical trials were encouraged to also join the CaD study at
their first and second annual visits.
There were 36,282 postmenopausal women aged 50-79 randomized into one of two study groups.
One group took 1,000 mg of calcium
carbonate and 400 International Units of vitamin D daily. The second group
took a placebo. Women who were already taking calcium supplements continued to
take them. Participants were followed for 7 to 11 years for this part of the
study and contacted by their clinical center every six months to assure their
safety and assess their health.