Recommendations for Cancer Prevention

8. Don't use supplements to protect against cancer.

To reduce your risk of cancer, choose a balanced diet with a variety of foods rather than taking supplements.

The expert report found strong evidence that high-dose supplements of some nutrients can affect the risk of different cancers. The panel judged that in general, the best source of nourishment is food and drink, not dietary supplements. Nutrient-rich whole foods contain substances that are necessary for good health–like fiber, vitamins, minerals and phytochemicals. (The plant-based foods are the source of many cancer-fighting compounds. Be sure to fill your plate two-thirds (or more) with a variety of vegetables, fruits, whole grains and beans, and one-third (or less) of animal protein.)

Some studies have shown that supplements can upset the balance of nutrients in the body. More research needs to be done, but this is one way that they might affect our risk of cancer.

There are some situations when supplements are recommended. These are the most common situations when taking a supplement can be beneficial:

  • All women of childbearing age intending to conceive a child should take a folic acid supplement before conception and up to the twelfth week of pregnancy.
  • Pregnant women and nursing mothers should also take a vitamin D supplement and possibly an iron supplement if their iron levels are low.
  • Children between six months and five years could benefit from taking drops containing vitamins A, C and D, although children with a good appetite who eat a wide variety of foods may not need them.
  • Frail older people who have low calorie needs may benefit from a low-dose, balanced multi-vitamin.
  • Older people should consider taking a vitamin D supplement, as should: people who rarely go outdoors, people who cover up all their skin when outdoors, those who don’t eat meat or oily fish.

If you want more advice on any of these situations, it’s best to contact your doctor or a registered dietitian.