Calcium/Vitamin D Supplementation Study Fact Sheet

WHAT WAS THE PURPOSE OF THE CALCIUM/VITAMIN D (CAD) SUPPLEMENTATION STUDY?

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.

SELECTED CAD FINDINGS