Ok, so I heard from some sources that Vitamin C can damage DNA, but several others say that this is unsupported. I was jsut wondering if the Teeming Millions could issue the final verdict since after checking the archives the great cecil has not addressed it.
If you mix pure DNA in solution with very high concentration ascorbic acid (vitamin C) there is some chance of degradation just because the pH of the solution might contribute to hydrolysis. Eating a few oranges a day is far too little vitamin C in far too much body to have anything like this effect. Likewise, in a cell, DNA is almost always intimately associated with all manner of proteins and is in a buffered solution.
Cite: Check any modern collegiate cell biology textbook.