I started taking vitamins during my six-month supervised diet since my dietitian wanted me to get used to taking them (but I think it was just the multi she had me taking, now that I think of it...), but most surgeons, regardless of the surgery, will have you stop taking vitamins and any non-prescription meds a week or two before surgery. I had to stop taking them before both of my plastic surgery procedures, too - evidently some can thin the blood too much, which can interfere with the surgery.
as for your anxiety meds (or any other prescription med), ask your doctor.