Vitamins and Minerals Role in Preventing and Fighting Cancer 

Beta carotene may be beneficial in its natural form, bound up with other constituents of food, but may not be as beneficial when it is isolated as a supplement. It is also possible that other carotenoids may be the real cancer inhibitors, and that they may be more efficacious against some types of carcinogens and tumors than others.

Calcium appears to have some preventive value especially with colon cancer. Researchers propose several mechanisms to explain how calcium acts as an anti-cancer warrior in the colon; these include inhibiting cell growth and/or disarming potential toxins by binding them to fatty acids.

Selenium is being actively studied by epidemiologists and basic scientists with mixed results. Interest was sparked by epidemiologic evidence that population groups with higher selenium intakes have less cancer than those who consume little of this trace mineral.

Vitamin A is what the body produces when it metabolizes carotenoids; it's also found in dairy products and animal fat. Some studies indicate that vitamin A itself, either from food or supplements, may also offer some cancer protection.

Vitamin D's role is unsettled right now; early studies indicated that it might provide some protection against colon cancer, but subsequent ones weren't as promising.

Folate (also known as folic acid) is best known for its role in the formation of healthy red blood cells. Now there's compelling epidemiologic evidence that people with higher folic acid levels are less likely than others to develop colon cancer and precancerous colon polyps.