If you are not seriously ill- do not take this much vitamin C. It is an  
antagonist to both zinc and copper from my understanding. At these levels you  
will develop a deficiency of both of these minerals. Pauling clearly had a  
copper deficiency at death. The white hair and the wrinkles are clear  
indications. 
You may be able to do it for years, but eventually it will kill  you. You may 
die at eighty but what if you would have died at a hundred instead?  Take 
super doses if you have cancer sure- it will enhance the lymphatic system's  
ability to carry out toxins and cancer cells. Of course this is just my  
understanding and I've been wrong before. Check out Dr. Joel Wallach's company  
American Longevity and call 'em up. They'll tell you about the copper/zinc  
thing.