ABSTRACT
This chapter proposes a theoretical epidemiological model of the possible efficacy of calcium that assumes that the dose-response relationship between intake of calcium and risk of colon cancer is linear. The peculiar geographic pattern of death rates from colonic cancer led to the suspicion that sunlight, vitamin D, and calcium might help prevent the disease. The geographic pattern of colon cancer and its association with relative deficiencies of ultraviolet light, vitamin D status, and calcium in individuals has a parallel in nutritional rickets. While fat has long been a suspected risk factor for colorectal cancer, dietary fat intake as measured by regional consumption patterns varies in the opposite direction to the geographic distribution of colon cancer in the United States. Cereal fiber has been suggested as a factor that might prevent colon cancer. Intake of fruits and vegetables has been surprisingly uniform in the United States, according to surveys completed by the United States Department of Agriculture.
