Doctor's Best Calcium Bone Maker Complex with Mch-Cal and VitaMK7 provides key bone nutrients in their most bioactive forms. Vitamin C assists bone matrix formation. Vitamin D3 helps support the absorption of calcium in the bone, while vitamin K2 helps direct the calcium to the bones. Mch-Cal contains natural elements founds in healthy bone including calcium, phosphorus, and type 1 collagen. Calcium helps support the muscles, nerves and blood vessels to move blood throughout the body that effect almost every function of the human body. Collagen helps build and support bone matrix and connective tissue. Mch-Cal helps support optimal bone mineral composition and overall bone health.