Vitamin D is not associated with serologic response to influenza vaccine in adults over 50 years old

Vitamin D deficiency has been implicated in risk of respiratory illness. We determined whether serum vitamin D levels are related to influenza vaccine response measured by hemagglutination antibody inhibition (HAI) titer in adults aged ≥50 years old. The study was a prospective cohort study conducted over two influenza seasons (fall 2008–spring 2009 and fall 2009–spring 2010) in Marshfield, WI and Nashville, TN including 1103 community-dwelling...