Bone protein, particularly in the form of bone morphogenetic proteins (BMPs) and other non-collagenous proteins found in bone matrix, has been studied mostly for its role in bone regeneration and healing rather than directly treating calcium deficiency. The rationale for its use in supporting calcium deficiency is based on the fact that bone proteins play a role in stimulating bone formation and remodeling. When used in the context of bone grafts or supplements derived from animal bone, bone protein may provide a scaffold and signaling molecules that help the body deposit new bone, which could theoretically support better calcium utilization and bone mineralization.

However, the direct evidence that bone protein supplementation treats or corrects calcium deficiency in humans is limited. Most clinical research focuses on BMPs in orthopedic and dental procedures for localized bone growth, not systemic calcium homeostasis. There are no large-scale, high-quality clinical trials demonstrating that oral or supplemental bone protein reverses or prevents calcium deficiency on its own. The scientific support for its use in this context is therefore weak, rating a 2 on the evidence scale—reflecting some plausible mechanism and indirect support, but a lack of direct, robust evidence. More research is needed to clarify any benefits for calcium deficiency beyond general bone health.