Microcrystalline Hydroxyapatite (M.C.H.A.), also known as Micro-crystalline Calcium Hydroxyapatite Complex (M.C.H.C.), is derived from raw bone and prepared by a special low temperature process (below 37 C) to preserve the protein content. The calcium thus provided is in an extremely bioavailable form. Vitamin D3 is because it is required for the absorption and utilization of calcium and phosphorus and is especially important for normal growth and development of bones and teeth. Vitamin K (both K1 and K2) is added support the synthesis of osteocalcin, the protein in bone tissue upon which calcium crystallizes.* However, because of its role in blood clotting, patients who have a problem in this area or who are taking medications to prevent blood clotting must carefully monitor their intake of vitamin K. For an MCHC product without vitamin K, see #834.Suggested Use One capsule four times daily. Four capsules supply 100% of the R.D.I. for calcium. Microcrystalline calcium hydroxyapatite is raw bone prepared by a special low temperature process (below 37C) to preserve the protein content. The calcium thus provided is in an extremely bioavailable form. In addition, the product may contain trace amounts of other beneficial minerals.Serving Size:1 Capsule Servings Per Container: 120 Amount Per Serving % Daily Value Vitamin D3 (as cholecalciferol) 250 IU 63% Vitamin K 45 mcg 56% Vitamin K2 (as menaquinone-7) 25 mcg Vitamin K1 (as phytonadione) 20 mcg Calcium (from M.C.H.A. and calcium citrate) 250 mg 25% Phosphorus (from M.C.H.A.) 56 mg 6% Boron (as boron aspartate) 750 mcg Other Ingredients: gelatin, vegetable lubricant Warnings Pregnant and/or lactating women should consult their physician prior to use. May contain soy. Tamper evident band around cap and seal on bottle. Do not use if either seal is broken or missing. Keep out of reach of children.