I looked up the name of the vitamine C supplement I take. It is a highly pure vitamine c and is absorbed througout 24h, so you don't have an outburst of effects and then nothing.
Ok, it is from the company NOW, and is called Vitamin C 1000 complex.
Nomally, you sould take one pill per day but I found two pills to do more for the motility. It is safe to take more vitamine C as it is water-soluble; the rest is exreted with your urine, so you don't do any harm to your body when taking more.
Hope it helps somewhat.