Researchers at Creighton University School of medicine in Omaha, Nebraska have determined that most Americans and others are not taking enough vitamin D, a deficiency that may place them at greater risk for developing several cancers.
The four year, randomized study followed almost 1200 healthy, postmenopausal women from rural eastern Nebraska. The study participants that took vitamin D3 supplements, almost three times the US government’s RDA (recommended daily amount) and calcium, experienced a significant reduction-60 per cent or more in cancer risk, compared to women who did not take the vitamin.
The study was conducted between 200 and 2005. Its findings were reported in the June 8, 2011 online edition of the American Journal of Clinical Nutrition.
Principal Investigator, Joan Lappe, Ph.D., R.N., professor of medicine and nursing, said, “The findings are very exciting. They confirm what a number of vitamin D proponents has suspected for some time but that, until now have not been substantiated through clinical trial.”
The participants were all at least 55 years and free of known cancers for at least 10 years before entering the study. They were randomly assigned to take daily doses of 1,110 IU of vitamin D3 and 1,400-1,500 mg of supplemental calcium, calcium alone or placebos.
To negate the premise that some of the women had undiagnosed cancer when they entered the study, researchers then eliminated the first-year results and looked at the last three years of the study. When they did that, the results became even more dramatic with the calcium/vitamin D3 group showing a startling 77 percent reduction of developing cancer.
The three year analysis determined, there was no statistically significant difference in cancer incidence between participants taking placebos and those taking just calcium.
American Journal of Clinical Nutrition