CALCIUM CITRATE+MAGNESIUM+ZINC+VITAMIN D3 is a combination of four supplements, namely: Calcium citrate, vitamin D3, magnesium and zinc. Calcium citrate makes the bones stronger by increasing their density. It helps in treating and preventing low calcium levels. Vitamin D3 is a form of vitamin D which helps in the absorption of calcium. Magnesium aids in the absorption of calcium by converting vitamin D into its active form. Zinc is necessary for bone-building cells and inhibits the formation of cells that cause the breakdown of bones. Together, CALCIUM CITRATE+MAGNESIUM+ZINC+VITAMIN D3 helps in strengthening of bones.