A patient takes 500mg of elemental Calcium daily from Calcium Citrate tablets. Pharmacy only has in stock Calcium Carbonate bottles which come as 1000mg of Calcium Carbonate per tablet. How many tablets of Calcium Carbonate must the patient take to get the same amount of calcium daily? I understand that you have to go through the mEqs and mmols. I'm supposed to calculate the MW of CaCO3 which equals 100mg. Thus 100mg = 1 mmol of Ca in CaCO3. And 100mg = 2 mEqs of Ca ions, 50mg = 1 mEqs. So patient takes 10 mEqs of Calcium daily and there are 20 mEqs of Ca per tablet of CaCO3. So the answer should be that patient takes 1/2tab of Calcium Carbonate? Or must I always revert back to mEqs and mmols? Another thing I wanted to bring up was, I remember reading that Iron had X% of Fe/tab in one formulation while another formulation had Y% of Fe/tab. Could I apply that method, finding the amount of elemental iron in each tablet and figuring out how many tabs to give?