Does your calcium come from stone or the living sea? Stones are not part of our regular diet so why do we feed ourselves with chalk (calcium carbonate) as it is delivered in most calcium supplements? Royal Green Bone Food complex is developed with one goal: to contribute to the maintenance of normal bones. For this purpose we 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 but from a pure plant source which after harvest is instantly dried to retain and concentrate all nutrients (of which many different minerals). Then we add the best absorbable vitamin K2 (MK-7) and vitamin D3 for an optimal result in the body.