This indicates that it adheres to the strict standards of the U.S. Pharmacopoeia for dissolution, meaning that it will break down completely. The latest findings show that calcium citrate is most absorbable in supplement form, and may be taken between OR with meals. However, calcium citrate is difficult to pack into a pill. You have to take lots of pills to get the RDA of 800 mg. This is a very expensive way to get your calcium.
Calcium carbonate is the next best form, and a lot more calcium is available per pill.
Vitamin D helps assimilate calcium into our bones. Generally, drinking fortified milk and getting some sunshine is enough for most people. Elderly folks sometimes have a problem in this area.