Dr. Mark Moyad (Univ. of Michigan Medical Center, Director of Preventitve & Alternate Medicine) published a booklet, titled "Promoting Wellness for Prostate Cancer Patients". In the section dealing with dietary supplements and other over-counter products he states for calcium, "If any concern exists about bone health, take calcium supplements (1000 to 1500 mg/day), but those with a history of calcium stones need to take calcium citratre."
In his booklet, Dr. Moyad is cautious about the use of muti-vitamins. He states (page 46), "... less is more when it comes to multivitamins. It is possible that higher doses of these pills may feed prostate tumors. The real problem is that many men's multivitamins contain too high a concentration of antioxidants. Taking a women's multivitamin without iron or simply a children's multivitamin several times a week, not to exceed one multivitamin pill a day, makes sense."
I switched to a one a day multi-vitamin (without minerals). I take it every other day.
Hope this helps.