I've been prescribed 50mg daily by my dermatologist for hair loss. It makes me nauseous if I don't have it directly after or with a meal and sometimes forget to take it.
If I forget too often I really start to notice it, dry and itchy skin, sensitivity to some metal jewelry and last but not least, wrinkles in my face!
I was tested before I started and was low. I suggest you get tested first too as it probably won't do much if you're not deficient.
I have no idea whether it will do anything for warts though, aren't they viral?