More bad new for vitamins to prevent cancer

 January is turning out to be a bad month for vitamins and their purported anticancer effects.

Researchers from Harvard Medical School in Boston add to the negative results.

First, the details.

  • 8171 women in the Women’s Antioxidant Cardiovascular Study were randomly assigned to take vitamin C (500 mg of ascorbic acid daily), natural-source vitamin E (600 IU of alpha-tocopherol every other day), and beta carotene (50 mg every other day) alone or in combination vs placebo.
  • 7627 of the women were cancer free before the study.

And, the results.

  • During the next 9 years, 624 women developed invasive cancer and 176 women died from cancer.
  • There was no statistically significant effect of any vitamin on total cancer incidence.
  • Duration and combined use of the 3 antioxidants also had no effect on cancer incidence and cancer death.
  • There were no differences in side effects among the groups.

The bottom line?
This is the second study this month to conclude that taking vitamin C doesn’t prevent cancer, and the third to conclude vitamin E doesn’t either. Both were summarized here.

It’s possible that the women who participated were not compliant with treatment. However, based on what we now know, taking vitamin E is not wise. It’s not a cancer preventative and may not be safe.

A review of the literature in 2005 concluded, “High-dosage (greater than 400 IU/day) vitamin E supplements may increase all-cause mortality and should be avoided.”

1/11/09 18:36 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.