A. Simply put, more forms of calcium ensure more complete availability in the body. Each calcium salt -- that is, each calcium attached to a different mineral -- offers differing quantities of elemental calcium. Elemental calcium is the "bottom line" amount of calcium you absorb from food or a supplement. While some calcium/mineral combinations have more elemental calcium than others, they're not always easy to absorb. For example, calcium lactate is about 32 percent absorbed while calcium citrate is approximately 30 percent absorbed. Tricalcium phosphate is an important addition to the formula because is the most prevalent form of calcium in human bone.

A. Calcium absorption varies based on many things, including the form of calcium as well as the presence of food in the digestive tract. While some research suggests that absorption might be a little better with food, it is not necessary to take calcium supplements with food to receive health benefits. If an individual has a sensitive stomach, we do recommend taking supplements with food to lessen the chance for stomach upset.