First author Benedetta Bartali, a a postdoctoral fellow at the Yale School of Medicine in New Haven, Conn., and colleagues collected blood samples to measure the levels of micronutrients including folate, iron and vitamins B6, B12, D and E in the seniors.

The scientists assessed physical decline in the study participants over a three-year period using an objective test of three tasks: walking speed, rising repeatedly from a chair and standing balance.

"We evaluated the effects of several micronutrients and only vitamin E was significantly associated with decline in physical function," Bartali said in a statement. "The odds of declining in physical function was 1.62 times greater in persons with low levels of vitamin E compared with persons with higher levels."

The study, published in the Journal of the American Medical Association, suggested that an appropriate dietary intake of vitamin E may help reduce the decline in physical function among older people.

Only one person in the study used vitamin E supplements, so it is unknown whether the use of vitamin E supplements would have the same beneficial effect, Bartali said.