Effect of multivitamin and mineral supplementation on episodes of infection in nursing home residents: a randomized, placebo-controlled study.
OBJECTIVE
To evaluate the effect of vitamin and mineral supplementation on infections in an elderly institutionalized population.


METHODS
Eighteen-month, randomized, placebo-controlled trial.


METHODS
Twenty-one long-term care facilities.


METHODS
Seven hundred sixty-three subjects from 21 long-term care facilities.


METHODS
Participants were randomized to receive one multivitamin and mineral supplementation daily or placebo.


METHODS
The primary outcome was number of infections per subject. Secondary outcomes were antibiotic use and hospitalization rates. Infection control surveillance was conducted over 18 months using standardized criteria.


RESULTS
Outcome data from 748 subjects, mean age 85, were included in the intention-to-treat analysis. Using univariate analyses, there was no difference in infectious episodes between the supplemented and placebo groups (3.5 infections per 1,000 resident-days vs 3.8 infections per 1,000 resident-days, odds ratio (OR)=0.92, 95% confidence interval (CI)=0.82-1.03, P=.12). There was a reduction in antibiotic usage in the supplementation group, but this was not significant in the multivariate model. There was no difference in the number of hospital visits. In the multivariate analysis, the effect of multivitamin use on total number of infections was not significant (OR=0.77, 95% CI=0.54-1.1). Subjects without dementia had a greater rate of infections than those with dementia (OR=1.44, 95% CI=1.19-1.76). In post hoc subgroup analysis, subjects without dementia who received supplementation had a significantly lower rate of infections than those who received placebo (relative risk=0.81, 95% CI=0.66-0.99).


CONCLUSIONS
Overall, multivitamin and mineral supplementation does not have a significant effect on the incidence of infections in institutionalized seniors, although the subgroup of residents in long-term care without dementia may benefit from supplementation. Further research is needed to determine its effect in high-risk subgroups within the nursing home population.
Liu
Barbara A
BA
Department of Medicine, Regional Geriatric Program of Toronto, Toronto, ON, Canada. barbara.liu@sunnybrook.ca
McGeer
Allison
A
McArthur
Margaret A
MA
Simor
Andrew E
AE
Aghdassi
Elaheh
E
Davis
Lori
L
Allard
Johane P
JP
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D019587:Dietary Supplements; D005260:Female; D006707:Homes for the Aged; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D017053:Infection Control / Q000379:methods*; D007239:Infections / Q000188:drug therapy / Q000453:epidemiology*; D008297:Male; D008903:Minerals / Q000627:therapeutic use*; D009735:Nursing Homes; D014815:Vitamins / Q000627:therapeutic use*
D000900:Anti-Bacterial Agents; D008903:Minerals; D014815:Vitamins