Calcium is necessary to maintain normal bones and teeth. Calcium contributes to normal muscle function and normal functioning of digestive enzymes. It participates in normal energy-producing metabolic processes and normal impulse transmission. Calcium plays a role in cell division processes and cell specialization. Vitamin D contributes to the normal absorption/utilization of calcium and phosphorus, the maintenance of normal calcium levels in the blood, the maintenance of healthy bones, muscle function, and normal teeth. Vitamin D contributes to the normal functioning of the immune system and plays a role in cell division. Vitamin K is involved in the maintenance of normal bones and normal blood clotting.