Royal Green Bone Food Complex was developed to contribute to the maintenance of normal bones. For this purpose Royal Green have used the 4 most important ingredients from nature. The exclusive calcium and magnesium complex comes from a special red algae (Algas calcareas). So not from stone (for instance calcium carbonate), but from a pure plant source. Added to this is the best absorbable vitamin K2 (MK-7) and vitamin D3 for the optimal transport and absorption of the calcium and magnesium in the body. Calcium, magnesium, vitamin D and vitamin K contribute to the maintenance of normal bones,contribute to a normal functioning of the muscles, the maintenance of teeth and the normal functioning of the immune system.