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Supplements and Cancer

AICR recommends against relying on supplements to protect against cancer.


The evidence is clear that a balanced, healthy diet can lower cancer risk. Nutrient-rich whole foods contain substances that are necessary for good health like fiber, vitamins and minerals.

These foods also contain non-nutrient substances collectively called phytochemicals that have shown the ability to protect against cancer in laboratory studies.

Although some of these substances are available as supplements, scientists cannot be sure that we’d get the same benefit when we consume them in this form.

And while it’s true that some studies have suggested certain supplements might offer protection, these trials have often been conducted among a specific, often high-risk group of people, so the observed benefits might not apply to the general population.

Another concern: Research shows that taking high doses of some supplements could be harmful to our health.

For most people, it’s sensible to get nutrients from whole foods. By eating a balanced diet rich in vegetables, fruits, whole grains and beans, most of us should be able to obtain all the nutrients we need.

Remember: AICR cautions against using supplements to protect against cancer, not against using supplements at all. Some people may derive other health benefits from supplement use.

Who Should Take Supplements?

  • Pregnant and breastfeeding women should check with their doctor about their need for folic acid, iron or vitamin D supplements.
  • Those at risk for vitamin D deficiency may include individuals who are dark-skinned or live in northern latitudes; the elderly; pregnant or breastfeeding women and exclusively breastfed infants; and children and adolescents who don’t consume enough fortified milk or other foods to get 400 IU daily.
  • People at risk for osteoporosis may require calcium and vitamin D supplements.
  • People at risk for B-12 deficiency may include men and women over age 50 and vegans who consume no animal foods at all. If you want more advice on any of these situations, it’s best to contact your doctor or a registered dietitian.

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

Published on 12/31/2099