Colorectal cancer is one of the most common cancer types. Although the diet is of huge importance, the understanding of minerals and their interactions and preventative effect is limited. Earlier studies have shown that calcium and selenium have protective roles. It also looks as if having more selenium in the blood can improve the effect of calcium. This was demonstrated in a new Polish study that is published in BMC Nutrition. The scientists point out that there is widespread selenium deficiency in Europe and that supplementation may be needed.