Vitamin use after cancer questioned

SEATTLE, Feb. 1 (UPI) -- A U.S. report suggested that not enough research has been conducted into the use of vitamin and mineral supplements among cancer survivors.

A review of scientific literature conducted by researchers at Fred Hutchinson Cancer Research Center in Seattle published in the Journal of Clinical Oncology, found that 64 percent to 81 percent of cancer survivors reported using vitamins or minerals despite inconclusive evidence of any benefit.

"While supplement use may be beneficial for some patients, such as those who cannot eat a balanced diet, research suggests that certain supplements may actually interfere with treatment or even accelerate cancer growth," senior author Cornelia Ulrich of the Hutchinson Center's Public Health Sciences Division said Friday in a release.

The report found that up to 68 percent of cancer survivors who use supplements don't tell their doctors know what they are taking. Ulrich said patients who fail to disclose supplement use risk potential adverse effects.

"Some vitamins, such as folic acid, may be involved in cancer progression while others, such as St. John's wort, can interfere with chemotherapy," she said.