Vitamin E may worsen acute respiratory tract infections in the elderly

ABSTRACT

BACKGROUND: The geriatric population has a potentially increased risk of infectious diseases and related sequelae because of decreasing immunocompetency. Currently available trials assessing efficacy of multivitamins and minerals are limited and contradictory. In this study the authors compared whether daily supplementation with a multivitamin containing minerals, with or without vitamin E, or vitamin E alone, affected the incidence and severity of acute respiratory tract infections in elderly individuals.

POPULATION STUDIED: The study population included 652 noninstitutionalized men and women living in the Netherlands who were at least 60 years of age. Patients were excluded if they were taking immunosuppressive agents, anticoagulants that could interfere with vitamin K metabolism, or dietary supplements within the preceding 2 months. Additional exclusion criteria included a history of cancer, liver disease, or fat malabsorption within the preceding 5 years.

STUDY DESIGN AND VALIDITY: Allocation assignment was concealed in this randomized, placebo-controlled trial. Participants took either 2 capsules daily of a multivitamin and mineral complex; vitamin E (200 mg/dL α-tocopheryl acetate); multivitamin-mineral complex plus vitamin E; or placebo for a maximum of 15 months. Doses of multivitamins were at recommended daily allowance (RDA) levels and doses of minerals were 25% to 50% of RDA levels. Patients recorded signs and acute symptoms of respiratory tract infections using a diary. A study nurse confirmed possible respiratory tract infections based on predetermined definitions. Data analysis was performed on an intention-to-treat and per-protocol basis.

OUTCOMES MEASURED: The primary outcomes measured were incidence and severity of acute respiratory tract infections. Microbiology and serology testing for 9 common respiratory pathogens was preformed for a random subsample of symptomatic patients. Baseline and post-study plasma levels of α-tocopherol, ascorbic acid, retinol, and carotenoids were also measured.

RESULTS: After a median study duration of 441 days, 1024 episodes of acute respiratory tract infections were reported by 68% of the participants. Of the 74.4% of these reported to the study nurse, 99.2% were confirmed as respiratory tract infections. Of the 107 symptomatic episodes randomly selected for microbiological testing, 58% had a confirmed pathogen, the most common being rhinovirus (54%). When treatment groups were evaluated individually compared with placebo, results were similar for all aspects of incidence and severity of acute respiratory tract infection, except that more patients in the multivitamin-mineral treatment group experienced a significant reduction in activity restriction (34.8% vs 48.5%; P = .04; number needed to treat = 8). Participants taking either multivitamin-mineral or vitamin E supplementation did not have a decreased incidence rate ratio of acute respiratory tract infections, 0.95 (95% CI, 0.75–1.15) and 1.12 (95% CI, 0.88–1.25), respectively. Multivitamin-mineral supplementation had no effect on severity of infection, whereas vitamin E supplementation was associated with illnesses of significantly greater severity: median illness duration was 19 versus 14 days (P = .02); median number of symptoms was 6 versus 4 (P = .03); fever occurrence in 37% versus 25% (P = .009); and restriction of activity in 52% versus 41% (P = .02).

ABSTRACT

BACKGROUND: The geriatric population has a potentially increased risk of infectious diseases and related sequelae because of decreasing immunocompetency. Currently available trials assessing efficacy of multivitamins and minerals are limited and contradictory. In this study the authors compared whether daily supplementation with a multivitamin containing minerals, with or without vitamin E, or vitamin E alone, affected the incidence and severity of acute respiratory tract infections in elderly individuals.

POPULATION STUDIED: The study population included 652 noninstitutionalized men and women living in the Netherlands who were at least 60 years of age. Patients were excluded if they were taking immunosuppressive agents, anticoagulants that could interfere with vitamin K metabolism, or dietary supplements within the preceding 2 months. Additional exclusion criteria included a history of cancer, liver disease, or fat malabsorption within the preceding 5 years.

STUDY DESIGN AND VALIDITY: Allocation assignment was concealed in this randomized, placebo-controlled trial. Participants took either 2 capsules daily of a multivitamin and mineral complex; vitamin E (200 mg/dL α-tocopheryl acetate); multivitamin-mineral complex plus vitamin E; or placebo for a maximum of 15 months. Doses of multivitamins were at recommended daily allowance (RDA) levels and doses of minerals were 25% to 50% of RDA levels. Patients recorded signs and acute symptoms of respiratory tract infections using a diary. A study nurse confirmed possible respiratory tract infections based on predetermined definitions. Data analysis was performed on an intention-to-treat and per-protocol basis.

OUTCOMES MEASURED: The primary outcomes measured were incidence and severity of acute respiratory tract infections. Microbiology and serology testing for 9 common respiratory pathogens was preformed for a random subsample of symptomatic patients. Baseline and post-study plasma levels of α-tocopherol, ascorbic acid, retinol, and carotenoids were also measured.

RESULTS: After a median study duration of 441 days, 1024 episodes of acute respiratory tract infections were reported by 68% of the participants. Of the 74.4% of these reported to the study nurse, 99.2% were confirmed as respiratory tract infections. Of the 107 symptomatic episodes randomly selected for microbiological testing, 58% had a confirmed pathogen, the most common being rhinovirus (54%). When treatment groups were evaluated individually compared with placebo, results were similar for all aspects of incidence and severity of acute respiratory tract infection, except that more patients in the multivitamin-mineral treatment group experienced a significant reduction in activity restriction (34.8% vs 48.5%; P = .04; number needed to treat = 8). Participants taking either multivitamin-mineral or vitamin E supplementation did not have a decreased incidence rate ratio of acute respiratory tract infections, 0.95 (95% CI, 0.75–1.15) and 1.12 (95% CI, 0.88–1.25), respectively. Multivitamin-mineral supplementation had no effect on severity of infection, whereas vitamin E supplementation was associated with illnesses of significantly greater severity: median illness duration was 19 versus 14 days (P = .02); median number of symptoms was 6 versus 4 (P = .03); fever occurrence in 37% versus 25% (P = .009); and restriction of activity in 52% versus 41% (P = .02).

ABSTRACT

BACKGROUND: The geriatric population has a potentially increased risk of infectious diseases and related sequelae because of decreasing immunocompetency. Currently available trials assessing efficacy of multivitamins and minerals are limited and contradictory. In this study the authors compared whether daily supplementation with a multivitamin containing minerals, with or without vitamin E, or vitamin E alone, affected the incidence and severity of acute respiratory tract infections in elderly individuals.

POPULATION STUDIED: The study population included 652 noninstitutionalized men and women living in the Netherlands who were at least 60 years of age. Patients were excluded if they were taking immunosuppressive agents, anticoagulants that could interfere with vitamin K metabolism, or dietary supplements within the preceding 2 months. Additional exclusion criteria included a history of cancer, liver disease, or fat malabsorption within the preceding 5 years.

STUDY DESIGN AND VALIDITY: Allocation assignment was concealed in this randomized, placebo-controlled trial. Participants took either 2 capsules daily of a multivitamin and mineral complex; vitamin E (200 mg/dL α-tocopheryl acetate); multivitamin-mineral complex plus vitamin E; or placebo for a maximum of 15 months. Doses of multivitamins were at recommended daily allowance (RDA) levels and doses of minerals were 25% to 50% of RDA levels. Patients recorded signs and acute symptoms of respiratory tract infections using a diary. A study nurse confirmed possible respiratory tract infections based on predetermined definitions. Data analysis was performed on an intention-to-treat and per-protocol basis.

OUTCOMES MEASURED: The primary outcomes measured were incidence and severity of acute respiratory tract infections. Microbiology and serology testing for 9 common respiratory pathogens was preformed for a random subsample of symptomatic patients. Baseline and post-study plasma levels of α-tocopherol, ascorbic acid, retinol, and carotenoids were also measured.

RESULTS: After a median study duration of 441 days, 1024 episodes of acute respiratory tract infections were reported by 68% of the participants. Of the 74.4% of these reported to the study nurse, 99.2% were confirmed as respiratory tract infections. Of the 107 symptomatic episodes randomly selected for microbiological testing, 58% had a confirmed pathogen, the most common being rhinovirus (54%). When treatment groups were evaluated individually compared with placebo, results were similar for all aspects of incidence and severity of acute respiratory tract infection, except that more patients in the multivitamin-mineral treatment group experienced a significant reduction in activity restriction (34.8% vs 48.5%; P = .04; number needed to treat = 8). Participants taking either multivitamin-mineral or vitamin E supplementation did not have a decreased incidence rate ratio of acute respiratory tract infections, 0.95 (95% CI, 0.75–1.15) and 1.12 (95% CI, 0.88–1.25), respectively. Multivitamin-mineral supplementation had no effect on severity of infection, whereas vitamin E supplementation was associated with illnesses of significantly greater severity: median illness duration was 19 versus 14 days (P = .02); median number of symptoms was 6 versus 4 (P = .03); fever occurrence in 37% versus 25% (P = .009); and restriction of activity in 52% versus 41% (P = .02).