BACKGROUND: To our knowledge, no rigorously designed clinical trials have evaluated the relation between vitamin D and physician-diagnosed seasonal influenza. OBJECTIVE: We investigated the effect of vitamin D supplements on the incidence of seasonal influenza A in schoolchildren. DESIGN: From December 2008 through March 2009, we conducted a randomized, double-blind, placebo-controlled trial comparing vitamin D(3) supplements (1200 IU/d) with placebo in schoolchildren. The primary outcome was the incidence of influenza A, diagnosed with influenza antigen testing with a nasopharyngeal swab specimen. RESULTS: Influenza A occurred in 18 of 167 (10.8%) children in the vitamin D(3) group compared with 31 of 167 (18.6%) children in the placebo group [relative risk (RR), 0.58; 95% CI: 0.34, 0.99; P = 0.04]. The reduction in influenza A was more prominent in children who had not been taking other vitamin D supplements (RR: 0.36; 95% CI: 0.17, 0.79; P = 0.006) and who started nursery school after age 3 y (RR: 0.36; 95% CI: 0.17, 0.78; P = 0.005). In children with a previous diagnosis of asthma, asthma attacks as a secondary outcome occurred in 2 children receiving vitamin D(3) compared with 12 children receiving placebo (RR: 0.17; 95% CI: 0.04, 0.73; P = 0.006). CONCLUSION: This study suggests that vitamin D(3) supplementation during the winter may reduce the incidence of influenza A, especially in specific subgroups of schoolchildren. This trial was registered at https://center.umin.ac.jp as UMIN000001373.
RCT Entities:
BACKGROUND: To our knowledge, no rigorously designed clinical trials have evaluated the relation between vitamin D and physician-diagnosed seasonal influenza. OBJECTIVE: We investigated the effect of vitamin D supplements on the incidence of seasonal influenza A in schoolchildren. DESIGN: From December 2008 through March 2009, we conducted a randomized, double-blind, placebo-controlled trial comparing vitamin D(3) supplements (1200 IU/d) with placebo in schoolchildren. The primary outcome was the incidence of influenza A, diagnosed with influenza antigen testing with a nasopharyngeal swab specimen. RESULTS: Influenza A occurred in 18 of 167 (10.8%) children in the vitamin D(3) group compared with 31 of 167 (18.6%) children in the placebo group [relative risk (RR), 0.58; 95% CI: 0.34, 0.99; P = 0.04]. The reduction in influenza A was more prominent in children who had not been taking other vitamin D supplements (RR: 0.36; 95% CI: 0.17, 0.79; P = 0.006) and who started nursery school after age 3 y (RR: 0.36; 95% CI: 0.17, 0.78; P = 0.005). In children with a previous diagnosis of asthma, asthma attacks as a secondary outcome occurred in 2 children receiving vitamin D(3) compared with 12 children receiving placebo (RR: 0.17; 95% CI: 0.04, 0.73; P = 0.006). CONCLUSION: This study suggests that vitamin D(3) supplementation during the winter may reduce the incidence of influenza A, especially in specific subgroups of schoolchildren. This trial was registered at https://center.umin.ac.jp as UMIN000001373.
Authors: Brunhild M Halm; Jennifer F Lai; Ian Pagano; William Cooney; Reni A Soon; Adrian A Franke Journal: J Am Coll Nutr Date: 2013 Impact factor: 3.169
Authors: R P Laursen; L Lauritzen; C Ritz; C B Dyssegaard; A Astrup; K F Michaelsen; C T Damsgaard Journal: Eur J Clin Nutr Date: 2014-12-10 Impact factor: 4.016
Authors: G Michael Allan; Lynda Cranston; Adrienne Lindblad; James McCormack; Michael R Kolber; Scott Garrison; Christina Korownyk Journal: J Gen Intern Med Date: 2016-03-07 Impact factor: 5.128
Authors: Yueh-Ying Han; Josh Blatter; John M Brehm; Erick Forno; Augusto A Litonjua; Juan C Celedón Journal: Lancet Respir Med Date: 2013-07-31 Impact factor: 30.700