well, if you're feeling a cold coming on, and plenty of us are this winter as it drags on, you might want to start taking zinc supplements. a new study finds taken within 24 hours of the onset of the cold, it can shorten that cold by at least a day and says you'll have less severe symptoms and that zinc can actually reduce your risk of getting a cold. we asked dr. richard besser about that. >> reporter: everyone's looking for a silver bullet when it comes to prevention. in theory it may prevent the rhinovirus from attaching to your nose and throat and prevent the virus from multiplying in your body. the theory is great. the study is not. they're not looking at any new data. they're looking at everything that's been published so far. some studies show it works but in those studies some people were taken a 10 milligram lozenge every hour and a half they were awake. that's a lot of zinc. many people experience that metallic taste as well as nausea. you have to weigh those benefits -- i mean, those