Does vitamin C really help your immune system?

Numerous studies in the past have reported that increasing your intake of vitamin C helps boost immune response. This study was designed to determine the specific effects of vitamin C deficiency on the immune response to infection with influenza virus.

Lab animals inoculated with influenza were treated with vitamin C three weeks before inoculation. There were no differences in lung influenza virus between vitamin C–adequate and –deficient mice; however, signs of infection in the lungs in the vitamin C–deficient mice were greater at 1 and 3 days after infection but less at day seven compared with vitamin C–adequate mice. Also, at 3 days after infection, male vitamin C–deficient mice had less immune cell response compared with male controls. Vitamin C–deficient male mice also had greater immune activation as early as 1 day after infection compared with male controls. There were no differences in female mice. This study suggests that vitamin C is required for an efficient immune response in limiting lung infections after influenza virus infection.1

References:
1. J. Nutr. 136:2611-2616, October 2006