The effect of vitamin C on upper respiratory infections in adolescent swimmers: a randomized trial
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Naama W. Constantini & Gal Dubnov-Raz & Ben-Bassat Eyal & Elliot M. Berry & Avner H. Cohen & Harri Hemilن
- چاپ و سال / کشور: 2011
Description
The risk of upper respiratory infections (URIs) is increased in people who are under heavy physical stress, including recreational and competitive swimmers. Additional treatment options are needed, especially in the younger age group. The aim of this study was to determine whether 1 g/day vitamin C supplementation affects the rate, length, or severity of URIs in adolescent swimmers. We carried out a randomized, double-blind, placebo-controlled trial during three winter months, among 39 competitive young swimmers (mean age 13.8±1.6 years) in Jerusalem, Israel. Vitamin C had no effect on the incidence of URIs (rate ratio=1.01; 95% confidence interval (CI)=0.70–1.46). The duration of respiratory infections was 22% shorter in vitamin C group, but the difference was not statistically significant. However, we found a significant interaction between vitamin C effect and sex, so that vitamin C shortened the duration of infections in male swimmers by 47% (95% CI: -80% to -14%), but had no effect on female swimmers (difference in duration: +17%; 95% CI: -38% to +71%). The effect of vitamin C on the severity of URIs was also different between male and female swimmers, so that vitamin C was beneficial for males, but not for females. Our study indicates that vitamin C does not affect the rate of respiratory infections in competitive swimmers. Nevertheless, we found that vitamin C decreased the duration and severity of respiratory infections in male swimmers, but not in females. This finding warrants further research.
Eur J Pediatr (2011) 170:59–63 DOI 10.1007/s00431-010-1270-z Received: 3 April 2010 / Accepted: 24 July 2010 / Published online: 6 August 2010
