When it comes to daily values for vitamins in food, 100% refers to the minimum amount a "normal" human being needs to be optimally healthy, and nothing more. How much over the optimal amount becomes toxic varies widely from vitamin to vitamin, so the DV doesn't really say how much you have to go over the DV value before you start feeling ill effects.

For example, the 100% Daily Value for Vitamin A is 3,000 IU, while the amount needed for it to become toxic is about 300,000 (for a single use) or about 30,000 (if you're doing it every day for an extended period of time), which correspond to 10000% and 1000% of the daily value, respectively.