Oystercal 500Mg Tab 60’S Is A Combination Medication That Contains Calcium Carbonate And Vitamin D. It Is Used To Prevent Or Treat Low Blood Calcium Levels In People Who Do Not Get Enough Calcium From Their Diets. Calcium Is Necessary For Many Normal Functions Of The Body, Especially Bone Formation And Maintenance. Vitamin D Helps Your Body Absorb Calcium And Phosphorus