I've made the transition
and what I take is a "senior" multi-vitamin (has no iron for one thing) plus calcium 2x a day, which gives me about 1200 mg, and I rely on my food to give me the rest to make at least 1500 mg/day. Your doctor may have some other suggestions, and there are certainly lots of other vitamins/supplements out there. I took premarin for the hot flashes (I've had a hysterectomy so didn't need the progesterin that's in Prempro), and have found that the new lower dose does the trick.