A recent study found that vitamin D supplements reduced the incidence of influenza A in schoolchildren. The multicentre, randomised, double-blind, placebo-controlled, parallel-group trial studied 430 schoolchildren aged 6-15 years, over the Japanese winter between December 2008 and March 2009. The children were assigned a total of 1200IU of vitamin D3 daily (3 x 200IU tablets twice daily) or placebo. Asthma attacks were also prevented by vitamin D3 supplementation.
Source: Am J Clin Nutr 2010 May;91(5):1255-1260.
