Vitamin D supplementation does not increase immunogenicity of seasonal influenza vaccine in HIV-infected adults

The influence of vitamin D on influenza vaccine immunogenicity in HIV was assessed using data from a phase 3, randomized trial conducted during the 2008-2009 influ-enza season. Thirty-three percent of participants were on supplemental vitamin D at baseline. Neither seroconversion nor seroprotection were predicted by vitamin D use for any of the 3 vaccine strains. There is no evidence of improved influenza vaccine immunogenicity with vitamin D supplementation in this HIV-positive population.