As you will read from the link Chris gives you no supplements are needed and will most likely interfere with the fasting process. You will also read about the best way to get your vitamin D which is by getting some sun. Check out a few facts about vitamin D here:
It is well to be careful of getting duped into taking supplements you don't need in general. There can be good reason to take some (apparently) but in most cases you are guaranteed to get enough of what you need should you eat a healthy and varied diet.