USPSTF: Data on vitamins for cancer prevention lacking

November 18, 2013

Data are lacking to recommend for or against the use of vitamins, minerals, and multivitamin supplements for the prevention of cancer and cardiovascular disease, according to a new U.S. Preventive Services Task Force draft recommendation statement.

Data are lacking to recommend for or against the use of vitamins, minerals, and multivitamin supplements for the prevention of cancer and cardiovascular disease, according to a new U.S. Preventive Services Task Force (USPSTF) draft recommendation statement.

Large-scale trials on the use of vitamins for prostate cancer prevention showed either no effect on mortality or an increased risk of the disease after long-term follow-up, according to the report.

Vitamin and mineral supplements are commonly used in the United States, with half of adults taking at least one dietary supplement, according to the USPSTF. For this recommendation, the Task Force focused specifically on whether these nutrients could help reduce the risk of cardiovascular disease or cancer.

“In general, the Task Force found that there is not enough evidence to determine whether you can reduce your risk of cardiovascular disease or cancer by taking single or paired nutrients, or a multivitamin,” said Task Force co-chair Michael LeFevre, MD, MSPH. “However, there were two major exceptions: beta-carotene and vitamin E, both of which clearly do not help prevent these diseases.”

Based on the lack of evidence, the Task Force determined that it cannot recommend for or against taking vitamins and minerals alone, as pairs, or in a multivitamin in order to help prevent cancer or cardiovascular disease. However, the Task Force did find sufficient evidence to recommend against using either beta-carotene or vitamin E for the prevention of cardiovascular disease or cancer, and it issued a D recommendation for both nutrients.

Vitamin E, which has been the subject of prostate cancer prevention research, has been studied in four randomized trials that reported cancer incidence, with inconsistent results, the USPSTF said. The Alpha-Tocopherol Beta-Carotene Cancer Prevention trial reported a decreased prostate cancer incidence rate, but the effect did not persist with longer follow-up (N Engl J Med 1994; 330:1029-35). Conversely, the Task Force said the Selenium and Vitamin E Cancer Prevention Trial reported an increased risk of prostate cancer after extended follow-up (JAMA 2009; 301:39-51).

In a single trial of folic acid, an increased incidence of cancer was attributed to an excess number of prostate cancer deaths in the intervention group (Agency for Healthcare Research and Quality 2013; Evidence Report No. 108. AHRQ Publication No. 14-05199-EF-1).

“In the absence of clear evidence about the impact of most vitamins and multivitamins on cardiovascular disease and cancer, health care professionals should counsel their patients to eat a healthy, well-balanced diet that is rich in nutrients,” said Task Force member Wanda Nicholson, MD, MPH, MBA.

The USPSTF is providing an opportunity for public comment on this draft recommendation statement until Dec. 9. Comments can be submitted at www.uspreventiveservicestaskforce.org/tfcomment.htm.

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