We have previously discussed that vitamin C is not a useful supplement for lowering the risk of the [http://glenn-glenncardwell.blogspot.com/2011/01/vitamin-c.html common cold]. Our good friends at the Cochrane Database has crunched the science behind what might be a useful adjunct to scare away the common cold virus far better than an onion. The answer is zinc, but you have to get in early.
Zinc taken as a lozenge or syrup within 24 hours of cold symptoms being detected reduced both the severity and duration of the cold in otherwise healthy people. The zinc supplement will need to be taken for at least five days. For some, taking zinc can create side-effects of nausea, especially with the lozenges.
The problem is that no-one is really sure what is the effective dose of zinc. We need between 8mg (women) and 14mg (men) of zinc each day. The Nutrient Reference Values recommend that we don’t consume more than 40mg of zinc a day. There is also evidence that vitamin D, often low in winter, also helps keep the common cold at bay. Maybe, just maybe, D + Zinc could help you sail through your next cold.
Singh M, Das RR. Zinc for the common cold. Cochrane Database of Systemic Reviews 2011, Issue 2 (just put this info into your search engine and you will easily find this free downloadable pdf).