Pioneer Calcium Magnesium also features vitamin D, trace minerals and bone protein for a complex, bone nourishing formula. This product features exceptionally well-utilized forms of calcium (microcrystalline hydroxyapatite [MCH], citrate and malate), plus vitamin D-3, boron and magnesium from three sources for enhanced bioavailability. Pioneer's pure quality MCH comes from the freeze-dried, whole bone of pasture-fed New Zealand or Australian cattle. This naturally proportioned complex of inherent bone matrix proteins and key trace minerals delivers added nutritive support for healthy bone density. This product has been independently verified gluten free. It contains no added artificial preservatives, colors or flavors and undergoes a rigorous heavy metal, pesticide, herbicide and fungicide screening process.