> ps. meta analysis of 60 years of Vitamin C studies with placebo controls showed the opposite of what you are remembering, C did not prevent or reduce the comm

> ps. meta analysis of 60 years of Vitamin C studies with placebo controls showed the opposite of what you are remembering, C did not prevent or reduce the common cold symptoms/severity Looks like there were two conflicting studies [1][2]. One concludes Vitamin C reduces frequency of common cold, but has no effect on severity, and the other concludes Vitamin C reduces severity of common cold, but has no effect on incidence. This is disconcerting, because I recall quite clearly that the study was around 2010, was a massive study and concluded as I described above in my reply to OP. But these studies are from 2005 and 2013. Another from 2005, concerning a boost to immune system, states "These trials document that adequate intakes of vitamin C and zinc ameliorate symptoms and shorten the duration of respiratory tract infections including the common cold. Furthermore, vitamin C and zinc reduce the incidence and improve the outcome of pneumonia, malaria, and diarrhea infections, especially in children in developing countries." [3] [1] https://www.nature.com/articles/1602261 https://www.nature.com/articles/1602261 [2] https://pubmed.ncbi.nlm.nih.gov/23440782/ https://pubmed.ncbi.nlm.nih.gov/23440782/ [3] https://pubmed.ncbi.nlm.nih.gov/16373990/ https://pubmed.ncbi.nlm.nih.gov/16373990/