Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren.
Am J Clin Nutr. 2010 May;91(5):1255-60. doi: 10.3945/ajcn.2009.29094. Epub 2010 Mar 10.
Am J Clin Nutr. 2010.
PMID: 20219962
Clinical Trial.