In laboratory animals, an increase in dietary calcium has been demonstrated to reduce experimentally-induced colon cancer. Although these findings indicate a protective effect of calcium or low fat dairy foods against colon cancer, further studies are necessary to substantiate this role for calcium. Compared to colon cancer, relatively few studies have investigated the relationship between calcium intake and breast cancer. This strategy is contrary to calcium restriction which once was part of the standard treatment for stone-formers. A possible reason for this contradictory finding relates to calcium s ability to bind oxalate.
Oxalate is a substance found in many plants including spinach.
Calcium supplements may increase kidney stone risk because they are often taken between meals when they would not have the benefit of binding with intestinal oxalate. Although increasing dietary calcium, especially from foods, offers to be a promising approach to reducing the risk of kidney stones in hypercalciuric stone-formers, clinical trials of this strategy have yet to be conducted. Nevertheless, consuming recommended dietary intakes of calcium may be a safe, natural approach to alleviating PMS symptoms. Further studies, including clinical trials, are needed to substantiate these observational findings. Polycystic Ovary Syndrome.