A forum at the American Association for Cancer Research (AACR) Annual Meeting 2015 warns that use of over-the-counter dietary supplements may increase the risk of multiple health conditions and diseases if more than the recommended daily dosage is taken by patients.

Tim Byers, MD, MPH, of the University of Colorado Cancer Center, describes the research initiated over 20 years ago on the association between fruit and vegetable consumption and cancer risk. After Dr. Byers and others discovered that patients who consumed greater amounts of fruits and vegetables had a lower risk of developing cancer, studies on dietary supplementation and cancer with animal models were initiated with promising results.

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However, clinical trials with humans led to different outcomes; in one study on the effects of beta-keratin supplementation, exceeding the recommended daily dosage was associated with a 20% greater risk of developing lung cancer and heart disease. In another trial, folic acid increased the number of polyps in the colon despite assumptions to the contrary.

Byers emphasizes that when taken at the correct dosage, multivitamins and dietary supplements can be beneficial but that individuals can also obtain the recommended daily allowance of many vitamins and minerals via a healthy and balanced diet.

For more information visit UCDenver.edu.