How many different vitamins and Herbal supplements can I take at a time?

I want to start taking different vitamins and herbs for different things that bother me like mood swings, hormones, headaches, irregular cycle, ect. But everyone prescribes something different to take. Can I take everything that they prescribe at once? People have said to take st. johns wort, 5htp, b50 complex, magnesium, b2, b6What do you think?

vitamins don't cure anything but vitamin deficiency. just take vitimins if you don't have a well balanced meals.

I take the prenatal vitimin, 250mg (I think) magnesium, and a multi-mineral supplement. I just spoke with my Dr. about all those last Friday and she had no worries about taking them altogether and for TTC also. I've tried St. John's Wort (and kava kava or something like that) and didn't see any change in my mild depression. I don't know what 5htp is but all the others should be fine to take together. I learned from my nutrition classes is that you will absorb your vitamins from food and if you take a supplement you will absorb what else you need from that and probably flush the rest.