Calcium alone does not build bone. It needs partners. Bone Support pairs 600 mg of calcium with 300 mg of magnesium (a 2:1 ratio), then adds vitamin D3, vitamin K1, vitamin K2 as MK-7, boron and horsetail, so the minerals have what your body uses to put them to work.What each part does Calcium and magnesium: the building blocks of bone, in citrate and malate forms. Vitamin D3: supports calcium absorption. 1,000 IU per serving. Vitamin K1 and K2 (MK-7): support healthy calcium use in bone. Boron and horsetail: trace mineral and silica support for bone structure. What’s inside (per 4 capsules) Vitamin D3, 25 mcg (1,000 IU), 125% DV Vitamin K1, 500 mcg, 417% DV Calcium, 600 mg, 46% DV, as calcium citrate and malate Magnesium, 300 mg, 71% DV, as magnesium citrate, glycinate and malate Boron, 1,500 mcg, as boron citrate Horsetail (whole herb), 33 mg, 7% silica Vitamin K2, 12 mcg, as MK-7 (menaquinone-7) 45 servings per bottle (180 capsules) Other ingredients: vegetarian capsule (hypromellose, purified water), rice flour Common questionsHow do I take it?4 capsules a day, ideally split into two doses with meals, or as your practitioner recommends.Who should check with a practitioner first?Anyone taking a blood thinner such as warfarin (it contains vitamin K), anyone with kidney disease or a history of kidney stones, and anyone on thyroid medication or antibiotics. Calcium can interfere with some of these, so take them at least 4 hours apart.Why is there vitamin K in a bone formula?Vitamin K helps direct calcium to bone. This formula uses both K1 and the longer-lasting K2 form, MK-7.Formulated by practitioners, including Stephanie Grutz, ARNP, FNP-C. Made in an FDA-inspected, cGMP-compliant facility and third-party tested for identity, purity and potency.