Vitamin E Supplements May Cause Harm
[in common synthetic supplement form]
March 26, 1999
NEW YORK (Reuters) -- Contrary to popular belief, vitamin E supplements
appear to provide little benefit to health and may even cause harm, according to
researchers. They believe vitamin E and most other nutrients should be consumed via a
healthy, balanced diet.
"We should be cautious about taking vitamin supplements until
there's data to prove that they work, and here for ~e first time we have a study that
shows that vitamin E may actually be harmful," said lead author Dr. Loft Mosca of the
University of Michigan in Ann Arbor. Mosca presented the findings at the 39th.Annual Conference on
Cardiovascular Disease Epidemiology and Prevention held this week in Orlando, Florida.
Cardiovascular disease is associated with a gradual deposition of fatty
plaques on artery walls. This plaque forms through the oxidation in the blood of LDL
("bad") cholesterol. Specific nutrient called antioxidants are thought to
inhibit this oxidative process and protect against heart disease.
Mosca's team examined levels of intake of four antioxidants -- vitamins
E and C, beta-carotene, and folic acid -- in a group of 54 postmenopausal women. They then
compared rates of LDL oxidation in blood samples taken from each of the subjects.
The investigators found that women, whose vitamin E source was dietary,
displayed significant reductions in LDL oxidation. However, women who took in vitamin E
via supplements actually increased their oxidation levels. "The more they took in,
the worse their LDL oxidation," Mosca told Reuters Health in an interview.
She explained that the vitamin E found in supplements comes in the form
of alpha-tocopherol, while the vitamin E in food is manifested as a different compound,
gamma-tocopherol. Among suppler users, "alpha-tocopherol displaces the
gamma-tocopherol in our tissues, so that now all you've got is alpha-tocopherol instead of
gamma-tocopherol," Mosca explained - "and it may be the gamma-tocopherol
She notes that the American Heart Association has always recommended that Americans
obtain their nutrients from foods, not supplements. Studies investigating the health
benefits of vitamin supplements have tended to produce conflicting results.
According to Mosca, "we have no evidence that a multivitamin is beneficial, (so)
why then should we take it? It costs money, and now you have a study that says it
Nuts, monounsaturated vegetable oils, whole grains, and wheat germ are the
best dietary sources of vitamin E, according to experts. According to the Michigan study,
women who obtained the highest amounts of vitamin E from their diets also displayed the
lowest amounts of LDL oxidation. "You probably can't get too much (vitamin E)
in food," Mosca concluded.