Vitamin C Pills May Thicken Arteries

SAN DIEGO--A study released March 2 questioned the effects of vitamin C pills onarteries. Participants in the study, who took 500 milligrams of vitamin C daily for atleast a year, had a two and a half times greater rate of arterial thickening than thosewho avoided supplements. Clogged arteries--atherosclerosis--are the major underlying causeof heart attacks and strokes.

Researchers at the University of Southern California studied 573 middle-aged men andwomen, 30 percent of whom took vitamins. The study found that vitamin C in pill form, notin a multivitamin or in food, caused an accelerated thickening of the walls in thearteries found in the neck. The more that was taken, the faster the buildup.

"When you extract one component of food and give it at very high levels, you justdon't know what you are doing to the system," said Dr. James Dwyer, theepidemiologist who directed the study. "It may be adverse."

"This is a preliminary epidemiological study and it is important to put thereported findings in the context of all available information," said Dr. JeffreyBlumberg, chief of the Antioxidants Research Laboratory at the U.S. Department ofAgriculture (USDA). "This is the first report of any negative effect of vitamin C onthe arteries."

This study has not been published or peer reviewed.