Randomized controlled trial on influenza published today

March 12, 2010

Press Release:

This morning, the American Journal of Clinical Nutrition published a

multicenter, randomized, double-blind, placebo controlled trial of school

children showing vitamin D prevents influenza. A secondary finding was that

asthmatic children on placebo had six times more asthma attacks than did

children on vitamin D.

For information, contact the lead author, Dr. Mitsuyoshi Urashima at

urashima@...

Am J Clin Nutr. 2010 Mar 10. [Epub ahead of print]

Randomized trial of vitamin D supplementation to prevent seasonal influenza A in

schoolchildren.

Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H.

Division of Molecular Epidemiology Jikei University School of Medicine Minato-ku

Tokyo Japan.

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.

PMID: 20219962 [PubMed - as supplied by publisher

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