my dr, today asked me to take 2,000 units a day i,am 76 yrs old. When I went to store, found Coral Calcium 1,000 mg plus it has Vit D 3 & Magnesium, havent taken a bone supplemeny for a year or so , on Drs. order, now this calcium, want to make sure this is ok ( I now takeCentrum silver Women 50 Plus.) to take or should I wait to ask DR. should it be just calcium only. I dont want to get kidney stones,ect