Effect of daily vitamin E and multivitamin-mineral supplementation on acute respiratory tract infections in elderly persons: a randomized controlled trial.
BACKGROUND
Immune response in elderly individuals has been reported to improve after micronutrient supplementation. However, efficacy trials evaluating infectious diseases as outcomes are scarce and inconclusive.


OBJECTIVE
To investigate the effect of daily multivitamin-mineral and vitamin E supplementation on incidence and severity of acute respiratory tract infections in elderly individuals.


METHODS
A randomized, double blind, placebo-controlled, 2 x 2 factorial trial.


METHODS
A total of 652 noninstitutionalized individuals aged 60 years or older enrolled from 2 community-based sampling strategies in the Wageningen area of the Netherlands, conducted from 1998 to 2000. At baseline, 6% of participants had suboptimal ascorbic acid and 1.3% had suboptimal alpha-tocopherol plasma concentration.


METHODS
Physiological doses of multivitamin-minerals, 200 mg of vitamin E, both, or placebo.


METHODS
Incidence and severity of self-reported acute respiratory tract infections at 15 months, as assessed by a nurse (telephone contact), home visits, and microbiological and serological testing in subsets of patients.


RESULTS
During a median observation period of 441 days, 443 (68%) of 652 participants recorded 1024 respiratory tract infection episodes. The incidence rate ratio of acute respiratory tract infection for multivitamin-mineral supplementation was 0.95 (95% confidence interval, 0.75-1.15; P =.58) and for vitamin E supplementation, 1.12 (95% confidence interval, 0.88-1.25; P =.21). Severity of infections was not influenced by multivitamin-mineral supplementation. For vitamin E vs no vitamin E, severity was worse: median (interquartile range) for illness-duration was 19 (9-37) vs 14 (6-29) days, P =.02; number of symptoms, 6 (3-8) vs 4 (3-8), P =.03; presence of fever, 36.7% vs 25.2%, P =.009; and restriction of activity, 52.3% vs 41.1%, P =.02.


CONCLUSIONS
Neither daily multivitamin-mineral supplementation at physiological dose nor 200 mg of vitamin E showed a favorable effect on incidence and severity of acute respiratory tract infections in well-nourished noninstitutionalized elderly individuals. Instead we observed adverse effects of vitamin E on illness severity.
Graat
Judith M
JM
Division of Human Nutrition and Epidemiology, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands. Judith.Graat@staff.nutepi.wau.nl
Schouten
Evert G
EG
Kok
Frans J
FJ
D000208:Acute Disease; D000368:Aged; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008903:Minerals / Q000627:therapeutic use*; D012141:Respiratory Tract Infections / Q000145:classification / Q000453:epidemiology / Q000517:prevention & control*; D012720:Severity of Illness Index; D017211:Treatment Failure; D014810:Vitamin E / Q000627:therapeutic use*; D014815:Vitamins / Q000627:therapeutic use*
D008903:Minerals; D014815:Vitamins; D014810:Vitamin E