The research found nursing home residents supplemented with the vitamin were 20 percent less likely to get a cold and also had less colds over the study period than a placebo group.
"Common colds are frequent and associated with increased morbidity in this age group, and if confirmed, these findings suggest important implications for the well-being of the elderly," write the researchers in today's issue of the Journal of the American Medical Association (292,pp 828-836).
In addition, significantly fewer vitamin E participants acquired one or more respiratory tract infections - the primary outcome measured in the study - although the supplements did not impact the incidence or duration of such infections and there was no effect on lower respiratory tract infections.
However the research does expand on a number of previous studies suggesting that vitamin E could enhance immune response. Researcher Simin Nikbin Meydani from Tufts University, Boston, previously reported (JAMA, 1997, 277:1380-6) that vitamin E supplements in doses of 60, 200 and 800 IU reduced incidence of self-reported infections in the elderly by 30 per cent over placebo. Subjects supplemented with 200 IU showed the greatest response.
Annette Dickinson, president of the US trade association the Council for Responsible Nutrition, noted: "Meydani's group has previously shown that vitamin E supplementation improves measures of immune response. The current study shows an impact on actual disease incidence."
Meydani and colleagues enrolled 617 people, who were at least 65 years old, in 33 long-term care facilities from April 1998 to August 2001. The one-year trial aimed to look at whether vitamin E could prevent respiratory tract infections in nursing home residents, more prone to infections than independent-living elderly.
The number of elderly living in such facilities is increasing. In the United States, an estimated 43 percent of elderly people will be admitted to a nursing home, with more than 85 percent of them admitted to long-term care facilities, according to the study authors.
The study participants were randomized to two groups. All participants received a multivitamin capsule with 50 percent of the recommended daily allowance (RDA) for essential micronutrients. One group also received a daily capsule containing 200 IU of vitamin E and the control group received a placebo capsule. A total of 451 participants (73 per cent) completed the study.
"Vitamin E had no significant effect on incidence or number of days with infection for all, upper, or lower respiratory infections. However, fewer participants receiving vitamin E acquired one or more respiratory tract infections (65 percent versus 74 percent for completing participants), or upper respiratory tract infections (50 percent versus 62 percent for completing participants)," the authors found.
Dr Dickinson noted that while giving all of the participants a multivitamin was good procedure (since nursing home residents are known to be prone to inadequate nutrient intakes), "it is possible that the multivitamin attenuated the effects of the vitamin E supplement".
Infections in the elderly can result in decreased daily activity, prolonged recovery times, increased health care service use, and more frequent complications, including death.