There is an "overkill" limit to Vitamin C. After you body takes what it can use .... the rest gets flushed out, so don'y go crazy. I remember someone telling me about 2500 Mg is about all most people can handle at a time. The rest is just wasted.
I guess in juice form, you can't hurt anything... but the pills can make your stomache ache....and your urine output will be BRIGHT yellow. (useless footnote)