I fail to see why people would take this form of calcium which is insoluble in water (meaning it will either right through you, or accumulate as deposits) with not much background on its biological activity (as a supplement), when there are scientifically proven calcium supplements out there that are fully absorbable with less chances of causing harm. Is it the calicum you want to supplement? Calcium Citrate has good reputation of being absorbed well (I have tested this on msa with great feedback) or any ionic calcium solutions (Water oz and I think concentrace carry these).
Mike