Calcium Intake & Sun Exposure may Affect Cancer Rates
According to an article published in the Annals of the New York Academy of Science (1999;889:107-119). Areas of the world that do not get a lot of sun in the winter (due to air pollution or winter cloud cover), tend to have more colon cancer than areas that get a lot of sun. Death from the disease in the United States is less prevalent in the South than in the Northeast. It also tends to occur in areas that had high rates of rickets—caused by a deficiency of vitamin D. The combination of latitude, climate, and air pollution in the Northeast reduces exposure to the sun, preventing any synthesis of vitamin D during five months of winter. Breast cancer death rates in white women also increase with distance from the equator and are highest in areas with long winters. Other diseases, like MS, also seem to occur where there is less exposure to the sun.
Colon cancer rates also have been shown to be inversely proportional to the intake of calcium. These findings, consistent with laboratory results, show that most cases of the disease may be prevented with regular intake of approximately 1,800 mg per day of calcium and 800 IU per day (20 micrograms) of vitamin D3. (In women, an intake of approximately 1,000 mg of calcium per 1,000 calories eaten with 800 IU of vitamin D would be sufficient. In addition to lower mortality rates from colon cancer, epidemiological data suggest that intake of 800 IU/day of vitamin D may be associated with enhanced survival rates among breast cancer cases.