Caltrate with vitamin D contains 600 mg of calcium carbonate (elemental calcium) and 800 IU of vitamin D (cholecalciferol) per tablet. Vitamin D aids in the absorption of calcium. Aging significantly decreases the capacity to produce vitamin D, so adults over the age of 65 are particularly susceptible to vitamin D deficiency. You may also be at risk if you do not consume dairy products, since most consumption of vitamin D comes from fortified milk and cereal products.
