The calcium in this product is bonded with natural citric acid and is specially formulated form people with insufficient stomach acid. With Vitamin D for enhanced absorption.

Ingredients: Calcium (as Calcium Citrate, Calcium Hydroxide) 1000 mg, Vitamin D (as Cholecalciferol) (D-3)  400 IU 

Other Ingredients: Gelatin Capsule, Magnesium Stearate, Silica, Watercress Leaf, Dandelion Root and Parsley Leaf.