Citracals Maximum Plus are Calcium Citrate caplets that are designed to provide the calcium and vitamin D3 you may not get enough of from the foods you eat each day. Calcium is an essential mineral needed for bone health. Vitamin D3 promotes calcium absorption. Citracals Maximum Plus contains 650 mg of Calcium Citrate, minerals such as zinc, copper and manganese and 25 mcg (1000 IU) of vitamin D3 per serving to help achieve optimal bone health and defy bone aging.