Define Absorption of Calcium from dietary calcium supplements?

Absorption from dietary calcium supplements is important to know, since they are almost universally recommended for post menopausal women. As far as supplement tablets are concerned, tablet disintegration is an important consideration. In one study, absorption from different supplements were studied under similar test conditions and compared with absorption from milk. When 250 mg of calcium was given along with breakfast meal, the absorption was from calcium-citrate-inalate (35%), calcium carbonate (27%) and tri calcium phosphate (25%) which was similar to the calcium absorption from milk (29%). Another finding of importance is that calcium from calcium carbonate in achlorhydric patients is reduced only when taken on all empty stomach. When taken with a meal, the absorption is greatest when calcium is taken in doses of 500 mg or less and with foods.