Progressive Labs Coral Calcium offers support for bones and teeth by providing both with the needed calcium. Coral minerals are predigested by small sea animals that ingest the ionic ocean minerals and secrete them into a coral formation. Magnesium is very alkaline and maintains the body's proper pH. Vitamin D is added to aid in the absorption of calcium from the intestinal tract and the breakdown and assimilation of phosphorus. Recommended use: Take 2 vegetable capsules twice daily, or as directed by a healthcare professional.