8. Try to meet your nutrient needs through diet alone

A closer look at the recommendations for reducing your overall cancer risk

Dietary supplements are not recommended for cancer prevention

What are dietary supplements?

Dietary supplements include vitamins, minerals and natural health products, such as herbal remedies. Other substances found in foods, such as specific antioxidants (e.g. lycopene or vitamin C), may also be found in dietary supplements. These products are found in many forms including pills, powders and liquids.

Why aren't dietary supplements recommended for cancer prevention?

There is no link between taking dietary supplements and reduced breast cancer risk. You can meet all of your nutrient needs by eating a well-balanced and varied diet.

Whole foods contain hundreds of natural cancer protective substances, such as antioxidants and phytochemicals. Dietary supplements do not contain the same components as whole foods. For example, strawberries contain vitamin C, soluble fibre, antioxidants and many other substances. Taking a pill that contains vitamin C, soluble fibre and antioxidants does not give you the same potential health benefits as eating a strawberry. The vitamins, minerals and other cancer protective substances found in foods are digested and absorbed more easily than the vitamins and minerals found in dietary supplements.

Taking dietary supplements may make some people think that they do not need to eat a healthy, balanced diet. The evidence linking plant foods to lower cancer risk is based on eating whole foods, not taking supplements.

Can taking dietary supplements cause you any harm?

Yes. Many vitamins and minerals can cause harmful effects if they are consumed in high amounts for extended periods of time. These potential harmful effects are far more likely to occur from taking supplements than from eating whole foods. For example, taking beta-carotene supplements has been shown to promote cancer development among people who are at high risk of lung cancer. No link has been found between eating high amounts of foods that are rich in beta- carotene and increased lung cancer risk.

Should anyone take dietary supplements?

Yes, people who have been diagnosed with vitamin or mineral deficiencies and people with health conditions that affect their diet may benefit from taking dietary supplements. Pregnant women may benefit from taking a multivitamin supplement. Health Canada recommends that infants be given supplemental vitamin D and that men and women over 50 take a daily vitamin D supplement of 400 IU. Strict vegans and older adults may benefit from taking Vitamin B12 or other supplements. Consult a qualified health professional before taking a dietary supplement.