DALLAS Regular doses of vitamin E may reduce the risk of life-threatening blood clots in women, researchers reported on Monday.
But they cautioned that more research is needed to confirm the link in the prevention of the clots, known as venous thromboembolism, and said patients should not stop taking prescribed blood thinners.
"The data indicated that, in general, women taking vitamin E were 21 percent less likely to suffer a blood clot," the American Heart Association, which published the finding in its journal Circulation, said in a statement.
"This is an exciting and interesting finding, but I don't think it's proven," Dr. Robert Glynn of Harvard Medical School said.
The American Heart Association generally does not recommend antioxidant vitamins such as vitamin E for the prevention of cardiovascular diseases or conditions, which include blood clots.
The study by Glynn and his colleagues reviewed data from 39,876 women aged 45 and older taking part in the Women's Health Study. They were given either 600 international units of natural source vitamin E or a placebo.
The women were asked to take them on alternate days over a 10-year period and did not know if they were taking vitamin E or a placebo.
"During the 10-year study, 482 women -- 213 in the vitamin E group and 269 in the placebo group -- reported having a venous thromboembolism that was subsequently confirmed through review of medical records," the heart association said.
"In this study, venous thromboembolism occurred more often than heart attacks and almost as often as stroke. People don't realize how common it is," Glynn said.
Such blood clots can become fatal if the clot blocks the flow of blood to the lungs, heart or brain.
The study results also seemed to indicate that vitamin E was most beneficial to women who were genetically predisposed to get the clots.
A recent update to the American Heart Association's guidelines on cardiovascular disease prevention in women stated that antioxidant vitamin supplements such as vitamin E, C and beta carotene should not be used for the prevention of cardiovascular disease in women.
"A large placebo-controlled, randomized study failed to show any benefit from vitamin E on heart disease," it said, underscoring the need for more research on the subject.